Objective Campylobacter jejuni NCTC11168 is commonly used as a standard strain for flagellar biosynthesis research.In this report,two distinguished phenotypic isolates(CJ1Z,flhA mutant strain,lawn;CJ2S,flhA complement...Objective Campylobacter jejuni NCTC11168 is commonly used as a standard strain for flagellar biosynthesis research.In this report,two distinguished phenotypic isolates(CJ1Z,flhA mutant strain,lawn;CJ2S,flhA complemented strain,normal colony)appeared during laboratory passages for NCTC11168.Methods Phenotypic assessments,including motility plates,transmission electron microscopy,biofilm formation assay,autoagglutination assay,and genome re-sequencing for these two isolates(CJ1Z,flhA mutant strain;CJ2S,flhA complemented strain)were carried out in this study.Results Transmission electron microscopy revealed that the flagellum was lost in CJ1Z.Phenotypic assessments and genome sequencing of the two isolates were performed in this study.The capacity for biofilm formation,colony auto-agglutination,and isolate motility was reduced in the mutant CJ1Z.Comparative genomic analysis indicated a unique native nucleotide insertion in flhA(nt,2154)that caused the I719Y and I720Y mutations and early truncation in flhA.Conclusion FlhA has been found to influence the expression of flagella in C.jejuni.To the best of our knowledge,this is the first study to describe the function of the C-terminal of this protein.展开更多
Phoebe bournei(Hemsl.) Yang is a rare and protected plant in China. This study was conducted to determine the phenotypic variation in this species and to document phenotypic variation within and among populations of...Phoebe bournei(Hemsl.) Yang is a rare and protected plant in China. This study was conducted to determine the phenotypic variation in this species and to document phenotypic variation within and among populations of P. bournei. Nested analysis of variance, coefficient of variation, multiple comparisons, principal component analysis(PCA) and correlation analysis were used to analyze ten phenotypic traits in ten natural populations of P.bournei from both the northeastern and the primary region of the range of this species. Significant differences among and within populations were observed in leaf and seed phenotypic traits. Variation among populations(34.92%)was greater than that within populations(26.19%). The mean phenotypic differentiation coefficient was 53.77% among populations, indicating that variation among populations comprised the majority of the phenotypic variation of P. bournei. The coefficient of variance(CV) of ten traits varied from 6.44 to 18.45%, with an average of 12.03%.The CV of leaf traits among populations(15.64%) was higher than that of seed traits(8.60%), indicating that seed traits were more stable. The results from CV and PCA indicated that leaf area, leaf length and thousand seed weight were the main factors accounting for the observed phenotypic variations. Significant or highly significant correlations were observed among most leaf and/or in seed phenotypic traits, whereas no significant correlations were observed between phenotypic traits and geographic factors.Based on cluster analysis, the ten populations can be divided into three clusters. These clusters were not a result of geographic distances.展开更多
To analyze the degree and pattern of phenotypic variation in leaves of Tetracentron sinense Oliv from the perspective of genetic and environmental adaptation and thus contribute to effective evidence-based conservatio...To analyze the degree and pattern of phenotypic variation in leaves of Tetracentron sinense Oliv from the perspective of genetic and environmental adaptation and thus contribute to effective evidence-based conservation and management strategies for germplasm resources,we measured 17 morphological and epidermal micromorphological leaf traits from 24 natural populations of T.sinense.Nested analysis of variance,multiple comparison,principal component analysis(PCA),cluster analysis,and correlation analysis were used to explore phenotypic leaf variation among and within populations and potential correlations with geographic and environmental factors.There were significant differences in 17 leaf phenotypic traits among and within populations.The mean phenotypic differentiation coefficient of the 17 traits was 56.34%,and the variation among populations(36.4%)was greater than that within populations(27.2%).The coefficient of variation(CV)of each trait ranged from 4.6 to 23.8%,and the mean was 11.8%.Phenotypic variation of leaves was related to environmental factors such as average annual sunshine hours,average July temperature,and average annual rainfall.The variation changed along gradients of longitude,latitude,and altitude.The PCA clustered the 24 natural populations into four groups.Our study suggests that phenotypic variation in T.sinense occurred primarily among populations,with moderate levels of phenotypic differentiation among populations and low levels of phenotypic variation within populations.The plant’s poor adaptability to the environment is likely an important contributor to its endangerment.Accordingly,conservation strategies are proposed to protect and manage the natural populations of T.sinense.展开更多
Mauremys mutica(Cantor,1842)is an endangered species in China.Main phenotypic variations inbody color,body weight,body shape,clutch size,egg size,and hatchling size were revealed betweenthe southern and northern popul...Mauremys mutica(Cantor,1842)is an endangered species in China.Main phenotypic variations inbody color,body weight,body shape,clutch size,egg size,and hatchling size were revealed betweenthe southern and northern populations.Both populations have the phenomenon of'larger male'sexualsize dimorphism(SSD),especially in the southern population.Furthermore,genetic variations betweenthe two populations were analyzed by RAPD band patterns of 30 random individuals in each population.The average genetic distance was 0.299±0.108 among the samples of two populations.The average ge-netic distance between southern and northern populations was 0.305±0.046.Cluster analysis indicatedthat all the individuals from the southern and northern populations were clustered among themselves toform two distinct clades.A total of 20 population-specific RAPD fragments were scored from 16 primers,and could be used as RAPD markers for distinguishing the southern and the northern population.Basedon the nucleotide sequences of two RAPD markers,two pairs of SCAR primers(SC1-S and SC2-S)weredesigned,which could be used as SCAR markers for the southern population.According to the significantphenotypic and genetic variations,we suggested that the northern population and southern populationmight be considered as two separate taxa,the'northern taxon'and the'southern taxon',and the con-servation should be respectively conducted on the two taxa.展开更多
Lespedeza bicolor Turcz is a native shrub in the temperate region of China. Thirteen provenances of L. bicolor were investigated in our study. Morphological diversity among and within provenances were analyzed based o...Lespedeza bicolor Turcz is a native shrub in the temperate region of China. Thirteen provenances of L. bicolor were investigated in our study. Morphological diversity among and within provenances were analyzed based on 19 phenotypic traits, including seven vegetative growth characteristics, nine floral traits and three pod characteristics. The coefficient of variation (CV) ranged from 6.4% to 65.4% and the phenotypic differentiation coefficient from 43.3% to 97.3%. Analyses of variance showed that there were extremely significant variations among and within provenances in pod length. Differences in plant height, inter-nodal length, number of branches, leaf width, leaf length and leaf area were not remarkable among provenance, but distinct within provenances. Other traits showed evidence of contrasts. Variation among provenances was the main part of phenotypic variation. Correlation analysis indicated that there were highly significant positive correlations between plant height and other vegetative growth characteristics. Floral traits were not associated with vegetative growth characteristics. The 13 provenances of L. bicolor investigated can be classified into three groups according to a UPGMA cluster analysis.展开更多
The phenotypic variation and its distribution among species,morphotypes,and among and within populations was estimated in 71 populations pertaining to 15 morphotypes of three domesticated species of Capsicum from Mexi...The phenotypic variation and its distribution among species,morphotypes,and among and within populations was estimated in 71 populations pertaining to 15 morphotypes of three domesticated species of Capsicum from Mexico.Collections were made in the states of Sinaloa,Nayarit,Oaxaca,Tabasco,and Yucatán in two agroecosystems:Backyard-garden and monoculture.Fifteen phenotypic characteristics were analyzed through one-way variance analysis and multivariate analyses of principal components analysis(PCA)and hierarchical clustering using Ward’s method.The study was performed in a uniform greenhouse experiment.A high variation was found among and within populations in all the measured characteristics.Of the total variation,13.0%was distributed among species,27.9%among morphotypes,8.1%among populations,and 51.0%within populations.Because plants grew in a uniform environment,these results indicate that the differences observed among and within species,morphotypes,and populations have a genetic basis.Univariate and multivariate analyses clearly differentiated morphotypes,suggesting that the category of morphotypes must be used to nominate the infraspecific variation in the domesticated Capsicum.The principal components analysis identified a total of 15 principal components that contributed to explain the total variation.The first two components explained 59.64%of the total variation and seven components explained more than 90%of the total variation.Among the measured characteristics,number of seed per fruit,weight of the fruit,width of the fruit,length of the fruit,stem diameter,days to flowering,and height of the plant contributed to component 1 variation,whereas width of the leaf,length of the leaf,and number of locules,number of fruits and number of seeds per plant contributed to component 2.The hierarchical clustering separated the populations and the morphotypes in two large different groups.One group consisted of populations collected in monoculture conditions and the other group corresponded to population collected from backyard-garden conditions.The monoculture populations were characterized mainly by their longer,wider,and higher weight fruits,plants were of less height,had smaller stem diameters,and lower number of fruits than the populations collected from the backyard-garden conditions.The backyard-garden populations of the Capsicum annuum and Capsicum frutescens species,considered wild or semi-domesticated,constituted a non-differentiated phenotypic group that does not allow dividing them in different species.展开更多
Of the various strategies adopted by an invasive plant species for expanding its niche breadth,phenotypic differentiation(either due to plasticity and/or adaptive evolution) is proven to be the most successful.Lately,...Of the various strategies adopted by an invasive plant species for expanding its niche breadth,phenotypic differentiation(either due to plasticity and/or adaptive evolution) is proven to be the most successful.Lately,we studied the persistence of substantial morpho-functional variations within the individuals of alien invasive plant,Parthenium hysterophorus in Chandigarh,India,through field surveys.Based on observed differences,the individuals were categorized into two morphotypes,PAand PB.PAhad higher leaf area,leaf biomass,and chlorophyll content as compared with PB.However,PBhad a higher stem circumference,stem specific density,twig dry matter content,profuse branching,bigger canopy,and better reproductive output than PA.To substantiate the persistence of intraspecific variations in P. hysterophorus and to deduce the possible genesis of these variations,we propagated both the morphotypes under experimental conditions in winter and summer.Apart from the key morpho-functional differences observed during the field studies,protein and carbohydrate metabolism were studied in leaves and roots of the propagated plants.Differences in plant metabolism were observed only during the early growth period,whereas the morpho-functional traits varied in the mature flowering plants.The effect of growth season was highly significant on all the studied morpho-functional and biochemical parameters(p ≤0.05).Parent morphotypes(P) and interactions between morphotypes and seasons significantly affected several growth parameters(p ≤0.05).The analyses revealed that the contrasting growth conditions at the time of transplantation and early growth may regulate the phenotype of P. hysterophorus.The pattern of intraspecific variations observed during the study is justified to consider morphotype PAas winter biotype and morphotype PBas summer biotype of P. hysterophorus.The study points towards the role of plasticity or a combination of genetic and environmental(G×E) factors in producing the phenotypic variability observed in the population of P. hysterophorus.展开更多
Gene expression changes contribute greatly to phenotypic variations in nature.Studying patterns of regulators of gene expression is important to fully understand the molecular mechanism underlying phenotypic variation...Gene expression changes contribute greatly to phenotypic variations in nature.Studying patterns of regulators of gene expression is important to fully understand the molecular mechanism underlying phenotypic variations.In horseshoe bats,the cochleae are fnely tuned to echoes of call frequency.Here,using 2 recently diverged subspecies of the intermediate horseshoe bat(Rhinolophus affnis hainanus and R.a.himalayanus)with great acoustic variations as the system,we aim to explore relative roles of different regulators of gene expression(differential gene expression,alternative splicing(AS)and long non-coding RNAs(lncRNAs))in phenotypic variation with a combination of Illumina short-read and Nanopore long-read RNA-seq data from the cochlea.Compared to R.a.hainanus,R.a.himalayanus exhibited much more upregulated differentially expressed genes(DEGs)and multiple of them may play important roles in the maintenance and damage repair of auditory hair cells.We identifed 411 differentially expressed lncRNAs and their target DEGs upregulated in R.a.himalayanus were also mainly involved in a protective mechanism for auditory hair cells.Using 3 different methods of AS analysis,we identifed several candidate alternatively spliced genes(ASGs)that expressed different isoforms which may be associated with acoustic divergence of the 2 subspecies.We observed signifcantly less overlap than expected between DEGs and ASGs,supporting complementary roles of differential gene expression and AS in generating phenotypic variations.Overall,our study highlights the importance of a combination of short-read and long-read RNA-seq data in examining the regulation of gene expression changes responsible for phenotypic variations.展开更多
X-linked adrenoleukodystrophy(X-ALD),an inborn error of peroxisomalβ-oxidation,is caused by defects in the ATP Binding Cassette Subfamily D Member 1(ABCD1)gene.X-ALD patients may be asymptomatic or present with sever...X-linked adrenoleukodystrophy(X-ALD),an inborn error of peroxisomalβ-oxidation,is caused by defects in the ATP Binding Cassette Subfamily D Member 1(ABCD1)gene.X-ALD patients may be asymptomatic or present with several clinical phenotypes varying from severe to mild,severe cerebral adrenoleukodystrophy to mild adrenomyeloneuropathy(AMN).Although most female heterozygotes present with AMN-like symptoms after 60 years of age,occasional cases of females with the cerebral form have been reported.Phenotypic variability has been described within the same kindreds and even among monozygotic twins.There is no association between the nature of ABCD1 mutation and the clinical phenotypes,and the molecular basis of phenotypic variability in X-ALD is yet to be resolved.Various genetic,epigenetic,and environmental influences are speculated to modify the disease onset and severity.In this review,we summarize the observations made in various studies investigating the potential modifying factors regulating the clinical manifestation of X-ALD,which could help understand the pathogenesis of the disease and develop suitable therapeutic strategies.展开更多
The investigation was carried out in focusing the genetic variability for different traits of wheat influenced by heat tolerance mechanism to find out relationships among phenological, physiological and yield contribu...The investigation was carried out in focusing the genetic variability for different traits of wheat influenced by heat tolerance mechanism to find out relationships among phenological, physiological and yield contributing traits. Spring wheat cultivar of 25 genotypes were selected and cultivated under late sowing condition at the Regional Wheat Research Institute, Shympur, Rajshahi, Bangladesh from December, 2016 to April, 2017. Significant variability among the genotypes exposed for different traits related to heat tolerance. Results showed that the genotypes G24, G10, G01, G13, G16, G25 and G14 </span><span style="font-family:Verdana;">ranked as better category considering maximum number of traits in mean</span><span style="font-family:Verdana;"> performance indicating their tolerance to heat stress under late sowing condition. Phenotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>) of all traits were greater than those of genotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>). The same trends were also found in their co-efficient of variances. The phenotypic co-efficient of variances (PCV) of all traits were greater compare to those of genotypic co-efficient of variances (GCV) and their values were closer to each other. The heading days (HD), canopy temperature at vegetative stage (CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">), canopy temperature at grain filling stage </span><span><span style="font-family:Verdana;">(CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">), biomass, plant height (PH), spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> (SPM), spikelet/spike (SPS), </span></span><span style="font-family:Verdana;">grain/</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">spike (GPS), thousand grain weight (TGW) and yield exhibited higher heritability (<i></span><span style="font-family:Verdana;">h<sub>b</sub><sup style="margin-left:-6px;">2</sup></span><span style="font-family:""><span style="font-family:Verdana;"></i>) estimated under irrigated late sowing (ILS) condition. Under the same ILS condition SPAD, SPM, SPS, GPS, TGW and yield showed moderate to high genetic advance (GA) obtained through computing their mean percentage (%) and the rest traits HD, maturity days (MD), CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">, CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">, biomass, PH and harvest index (HI) exposed smaller genetic advance (% mean). The co-efficient of variation (CV%) of all attributes in all genotypes were significantly lower (1.36</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">- 6.96). Both heritability and genetic advance were found lower for MD, SPAD and HI indicated their non additive genetic effects for </span><span style="font-family:Verdana;">which these traits might not be recommended for selection. However, </span><span style="font-family:Verdana;">spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">spikelet/spike, grain/spike, thousand grain weight and yield belonged to </span><span style="font-family:Verdana;">higher heritability and high to moderate genetic advance in mean percentage (%) along with wide genetic variation and lower environmental influence in heat stress situation indicated the most likely heritability due to the effects of additive genes that might be suggested as effective process of selection for these traits in heat stress condition.展开更多
Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh.It grows well in moderate saline zones with full sunlight.This study presents leaf morphological plasticity in ...Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh.It grows well in moderate saline zones with full sunlight.This study presents leaf morphological plasticity in B.sexangula to saline zones.Leaves were sampled from different saline zones and various morphological traits were measured.The results exposed a wide deviations of leaf size parameters:leaf length varied 6.6–17.3 cm;width 2.7–7.8 cm;upper quarter width 2.2–6.5 cm;down quarter width 2.5–7.3 cm;and petiole length 0.17–1.43 cm.Leaf length was significantly larger in fresh water than in other salinity zones,whereas,leaf width,upper and lower leaf quarters were significantly larger in medium saline zone.Leaf shape parameters showed a large variation among saline zones.Leaf base angle was significantly larger in both medium and strong salinity zones.Tip angle was significantly greater in medium salinity zone.Leaf perimeter was significantly larger in fresh water but leaf area was significantly bigger in medium saline zone.Leaf index and specific leaf area were maximum in moderate saline zone.Plasticity index was the highest in moderate saline for almost all the parameters presented.The ordination(PCA)showed clusters of leaf samples although there were some overlap among them which suggested a salt-stress relationship among salinity zones.The results indicate that B.sexangula had a plasticity strategy on leaf morphological parameters to salinity in the Sundarbans.This study will provide basic information of leaf plasticity of this species among saline zones which will help for site selection of coastal planting and will also provide information for policy makers to take necessary steps for its conservation.展开更多
Characterization of the reproductive morphology in genus </span><i><span style="font-family:Verdana;">Zingiber</span></i><span style="font-family:Verdana;"> is &...Characterization of the reproductive morphology in genus </span><i><span style="font-family:Verdana;">Zingiber</span></i><span style="font-family:Verdana;"> is </span><span style="font-family:Verdana;">still relevant on classical taxonomic studies because most of the species are phenotypically similar and difficult to distinguish in the absence of the flowering stage. Reports mainly derived based on the herbarium collections are insufficient for the detailed morphological review. </span><i><span style="font-family:Verdana;">Zingiber</span></i><span style="font-family:Verdana;"> <i>barbatum</i> </span><span style="font-family:Verdana;">(Wall.) belongs to the genus </span><i><span style="font-family:Verdana;">Zingiber</span></i><span> </span><span style="font-family:Verdana;">and has been neglected for a long time. Existed intraspecific morphological and genetic variations also intricate the description of this sp</span><span style="font-family:Verdana;">ecies. The objective of this study was to characterize the reproductive morphology</span><span style="font-family:Verdana;"> of under-exploited </span><i><span style="font-family:Verdana;">Z.</span></i><span style="font-family:Verdana;"> <i>barbatum</i> </span><span style="font-family:Verdana;">species. The study was done based on the traditional description of morphology and habit of inflorescence and flowers, with a recording of minimum quantitative and qualitative parameters and phenological observation regarding inflorescence life span and duration of blossom. Assessment of reproductive morphology dis</span><span style="font-family:Verdana;">played phenotypic variations regarding inflorescences habit during the growth</span><span style="font-family:Verdana;"> stage and morphological features of the flower. Perhaps, an existed variation was driven by eco-geographical factors resulting in reproductive isolation due to which genetic divergence might occur. The taxonomic affiliation of </span><i><span style="font-family:Verdana;">Z.</span></i><span style="font-family:Verdana;"> <i>barbatum</i> </span><span style="font-family:Verdana;">based on inflorescence habit has been confirmed. This is the first comprehensive report regarding flower biology on </span><i><span style="font-family:Verdana;">Z.</span></i><span style="font-family:Verdana;"> <i>barbatum</i></span><span style="font-family:Verdana;">.展开更多
The study investigated genotypic and phenotypic co-efficients of variation, heritability, genetic advance at 5% selection intensity and in percentage of population mean of nine characters (plant height, leaf number, l...The study investigated genotypic and phenotypic co-efficients of variation, heritability, genetic advance at 5% selection intensity and in percentage of population mean of nine characters (plant height, leaf number, length and width of leaf lamina, number and weight of cormels per plant, weight of corm per plant, dry matter percentage in the tubers and tuber yield per from 14 cultivars of taro [Colocasia esculenta (L.) Schott]). Results indicated highest genotypic co-efficient of variation for dry matter percentage (47.91), which was 95.78% of the phenotypic co-efficient of variation, whereas tuber yield per plant showed the widest range (819.37). Number of cormels per plant and dry matter percentage ehibited considerably higher heritability (84.90% and 91.70%, respectively) and genetic advance (81.19 and 79.00, respectively), indicating the potentiality of selection for improvement of such characters. These two characters were found to be positively correlated to tuber yield per plant. Path analysis revealed that weight of cormels per plant possessed the highest direct effect on tuber yield, indicating the importance of selection based on this character to increase tuber yield per plant.展开更多
Transposable elements(TEs), originally discovered in maize as controlling elements, are the main components of most eukaryotic genomes. TEs have been regarded as deleterious genomic parasites due to their ability to u...Transposable elements(TEs), originally discovered in maize as controlling elements, are the main components of most eukaryotic genomes. TEs have been regarded as deleterious genomic parasites due to their ability to undergo massive amplification. However, TEs can regulate gene expression and alter phenotypes. Also, emerging findings demonstrate that TEs can establish and rewire gene regulatory networks by genetic and epigenetic mechanisms. In this review, we summarize the key roles of TEs in fine-tuning the regulation of gene expression leading to phenotypic plasticity in plants and humans, and the implications for adaption and natural selection.展开更多
Understanding the genetic mechanisms for cadmium (Cd) uptake and translocation in common wheat (Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat culti...Understanding the genetic mechanisms for cadmium (Cd) uptake and translocation in common wheat (Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat cultivars was collected from the North China Plain. The cultivars were evaluated in terms of their phenotypic variations in response to Cd stress and subjected to a genome-wide association study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with the phenotypic variations at the seedling stage. Significant phenotypic variations with high heritability were observed among the wheat cultivars exposed to 40 μmol L-1 Cd for the studied traits, including root length (RL), shoot length (SL), root and shoot dry biomasses (RDW and SDW, respectively), root and shoot Cd concentrations (RCD and SCD, respectively), and Cd translocation factor (TF). Mean RCD, SCD, and TF ranged from 1.0 to 33.8, 0.125 to 2.022, and 0.009 to 0.321 mg g-1, respectively. Cluster analysis showed that wheat cultivars with higher RL, SL, RDW, and SDW under Cd stress were able to accumulate more Cd in root, leading to a lower Cd TF. Mixed linear model-based association analysis detected 17 novel significant marker-trait associations (MTAs), four of which were significant at a genome-wide scale. Most of the significant MTAs controlled Cd TF and explained 17.17%–26.47% of the phenotypic variations. Some of the SNP loci were physically close to a reported Cd-related quantitative trait locus or gene on wheat chromosomes. Results of this study provided a list of wheat cultivars with the potential of low Cd accumulation and enriched our knowledge on the genetic basis of Cd uptake and translocation in wheat. Pyramiding breeding of superior alleles detected in this study may additionally reduce Cd accumulation of improved wheat cultivars with excellent agronomic traits.展开更多
Fluctuating environments pose tremendous challenges to bacterial populations. It is observed in numerous bacterial species that individual cells can stochastically switch among multiple phenotypes for the population t...Fluctuating environments pose tremendous challenges to bacterial populations. It is observed in numerous bacterial species that individual cells can stochastically switch among multiple phenotypes for the population to survive in rapidly changing environments. This kind of phenotypic heterogeneity with stochastic phenotype switching is generally understood to be an adaptive bet-hedging strategy. Mathematical models are essential to gain a deeper insight into the principle behind bet-hedging and the pattern behind experimental data. Traditional deterministic models cannot provide a correct description of stochastic phenotype switching and bet-hedging, and traditional Markov chain models at the cellular level fail to explain their underlying molecular mechanisms. In this paper, we propose a nonlinear stochastic model of multistable bacterial systems at the molecular level. It turns out that our model not only provides a clear description of stochastic phenotype switching and bet-hedging within isogenic bacterial populations, but also provides a deeper insight into the analysis of multidimensional experimental data. Moreover, we use some deep mathematical theories to show that our stochastic model and traditional Markov chain models are essentially consistent and reflect the dynamic behavior of the bacterial system at two different time scales. In addition, we provide a quantitative characterization of the critical state of multistable bacterial systems and develop an effective data-driven method to identify the critical state without resorting to specific mathematical models.展开更多
Aims More data are needed about how genetic variation(GV)and envi-ronmental factors influence phenotypic variation within the natural populations of long-lived species with broad geographic distribu-tions.To fill this...Aims More data are needed about how genetic variation(GV)and envi-ronmental factors influence phenotypic variation within the natural populations of long-lived species with broad geographic distribu-tions.To fill this gap,we examined the correlations among envi-ronmental factors and phenotypic variation within and among 13 natural populations of Pinus tabulaeformis consisting of four demo-graphically distinct groups within the entire distributional range.Methods Using the Akaike’s information Criterion(AiC)model,we measured 12 morphological traits and constructed alternative candidate models for the relationships between each morphological trait and key climatic variables and genetic groups.We then compared the AiC weight for each candidate model to identify the best approximating model for ecogeographical variation of P.tabulaeformis.The partitioning of vari-ance was assessed subsequently by evaluating the independent vari-ables of the selected best models using partial redundancy analysis.Important Findings Significant phenotypic variation of the morphological traits was observed both within individual populations and among populations.Variation partition analyses showed that most of the phenotypic variation was co-determined by both GV and climatic factors.GV accounted for the largest proportion of reproductive trait variation,whereas local key climatic factors(i.e.actual evapotranspiration,AET)accounted for the largest proportion of phenotypic variation in the remaining investigated traits.Our results indicate that both genetic divergence and key environmental factors affect the phenotypic variation observed among populations of this species,and that reproductive and vegetative traits adaptively respond differently with respect to local environmental conditions.This partitioning of factors can inform those making predictions about phenotypic variation in response to future changes in climatic conditions(particularly those affecting AET).展开更多
Morphological variation of snails from the genus Trochulus is so huge that their taxonomy is unclear. The greatest variability concerns forms hispidus and sericeus/plebeius, which are often considered as separate spec...Morphological variation of snails from the genus Trochulus is so huge that their taxonomy is unclear. The greatest variability concerns forms hispidus and sericeus/plebeius, which are often considered as separate species. To evidence the species barriers, we carried out crossbreeding ex- periments between these two sympatric morphs. Moreover, we compared the shell morphology of laboratory-bred offspring with their wild parents to test if the variation can be explained by the phenotypic plasticity model. We found that the two Trochulus morphs show no reproductive bar- riers. The fecundity rates, the mean clutch size, and F~ viability observed for all crosses were not significantly different. In hybrid crosses (in F2 generation), we also recorded reproduction compati- bility, similar fecundity, and hatching success as in their parents. Accordingly, phylogenetic ana- lyses revealed the significant grouping of sequences from these different morphs and supported no constrains in reproduction between them. Comparison of shell morphology between wild and laboratory samples showed that various characters appeared highly plastic. The average shell shape of the hispidus morph changed significantly from flat with wide umbilicus to elevated with narrower umbilicus such as in the sericeus/plebeius morph. All these findings indicate that the examined morphs do not represent separate biological species and the evolutionary process is not advanced enough to separate their genetic pool. Therefore, phenotypic plasticity has played a sig- nificant role in the evolution of Trochulus shell polymorphism. The two morphs can evolve inde- pendently in separate phylogenetic lineages under the influence of local environmental conditions.展开更多
A fun dame ntal question in biology is how diversity evolves and why some clades are more diverse than others.Phenotypic diversity has often been shown to result from morphological adaptation to different habitats.The...A fun dame ntal question in biology is how diversity evolves and why some clades are more diverse than others.Phenotypic diversity has often been shown to result from morphological adaptation to different habitats.The role of behavioral interactions as a driver of broadscale phenotypic diversity has received comparatively less attention.Behavioral interactions,however,are a key agent of natural selection.Antagonistic behavioral interactions with predators or with parasites can have significant fitness consequences,and hence act as strong evolutionary forces on the phe no type of species,ultimately gen erating diversity betwee n species of both victims and exploiters.Avian obligate brood parasites lay their eggs in the nests of other species,their hosts,and this behavioral interaction between hosts and parasites is often considered one of the best examples of coevolution in the natural world.In this review,we use the coevolution between brood parasites and their hosts to illustrate the potential of behavioral interactions to drive evolution of phenotypic diversity at different taxonomic scales.We provide a bridge between behavioral ecology and macroevolution by describing how this interaction has increased avian phenotypic diversity not only in the brood parasitic clades but also in their hosts.展开更多
Bodies of plants are modularly organized. Development proceeds by adding new modules to open endings with a potential for branching. Each module is autonomous to some extent. Development relies on the self-organized p...Bodies of plants are modularly organized. Development proceeds by adding new modules to open endings with a potential for branching. Each module is autonomous to some extent. Development relies on the self-organized patterns that emerge from the interactions of individual modules. Interactions include both competition and cooperation,and several types of positive and negative feedback loops are involved. Development can be open to external influences, thus enabling the plant to adjust its form to the environment,for example, to the spatial distribution of ecological resources. This paper provides a review on adaptive plasticity in plants.展开更多
基金supported by the National Key Research and Development Program of China[2021YFC2301000]the Project for Novel Detection Techniques of Bacterial Pathogens[32073]+1 种基金Enhancement of Comprehensive Monitoring,Prevention,and Control Capabilities for Traditional Infectious Diseases Such as Plague,Cholera,and Brucellosis[102393230020020000002]Prevention and Intervention of Bacterial and Fungal Infectious Diseases[102393220020020000031]。
文摘Objective Campylobacter jejuni NCTC11168 is commonly used as a standard strain for flagellar biosynthesis research.In this report,two distinguished phenotypic isolates(CJ1Z,flhA mutant strain,lawn;CJ2S,flhA complemented strain,normal colony)appeared during laboratory passages for NCTC11168.Methods Phenotypic assessments,including motility plates,transmission electron microscopy,biofilm formation assay,autoagglutination assay,and genome re-sequencing for these two isolates(CJ1Z,flhA mutant strain;CJ2S,flhA complemented strain)were carried out in this study.Results Transmission electron microscopy revealed that the flagellum was lost in CJ1Z.Phenotypic assessments and genome sequencing of the two isolates were performed in this study.The capacity for biofilm formation,colony auto-agglutination,and isolate motility was reduced in the mutant CJ1Z.Comparative genomic analysis indicated a unique native nucleotide insertion in flhA(nt,2154)that caused the I719Y and I720Y mutations and early truncation in flhA.Conclusion FlhA has been found to influence the expression of flagella in C.jejuni.To the best of our knowledge,this is the first study to describe the function of the C-terminal of this protein.
基金financially supported by the Major Science and Technology Project(No.2010C12009)Agricultural New Varieties Breeding Project(No.2012C12908-4)Key Research and Development Plan(No.2017C02028)of Zhejiang Province,China
文摘Phoebe bournei(Hemsl.) Yang is a rare and protected plant in China. This study was conducted to determine the phenotypic variation in this species and to document phenotypic variation within and among populations of P. bournei. Nested analysis of variance, coefficient of variation, multiple comparisons, principal component analysis(PCA) and correlation analysis were used to analyze ten phenotypic traits in ten natural populations of P.bournei from both the northeastern and the primary region of the range of this species. Significant differences among and within populations were observed in leaf and seed phenotypic traits. Variation among populations(34.92%)was greater than that within populations(26.19%). The mean phenotypic differentiation coefficient was 53.77% among populations, indicating that variation among populations comprised the majority of the phenotypic variation of P. bournei. The coefficient of variance(CV) of ten traits varied from 6.44 to 18.45%, with an average of 12.03%.The CV of leaf traits among populations(15.64%) was higher than that of seed traits(8.60%), indicating that seed traits were more stable. The results from CV and PCA indicated that leaf area, leaf length and thousand seed weight were the main factors accounting for the observed phenotypic variations. Significant or highly significant correlations were observed among most leaf and/or in seed phenotypic traits, whereas no significant correlations were observed between phenotypic traits and geographic factors.Based on cluster analysis, the ten populations can be divided into three clusters. These clusters were not a result of geographic distances.
基金funded by the Sichuan Science and Technology Program,Sichuan Province,China(No.2017JY0164)the Special Fund for the Fourth General Survey of Chinese Medicine Resources in China(No.2018PC001)+1 种基金Meritocracy Research Funds of China West Normal University(No.17YC325)the Fundamental Research Funds of China West Normal University(No.18B026).
文摘To analyze the degree and pattern of phenotypic variation in leaves of Tetracentron sinense Oliv from the perspective of genetic and environmental adaptation and thus contribute to effective evidence-based conservation and management strategies for germplasm resources,we measured 17 morphological and epidermal micromorphological leaf traits from 24 natural populations of T.sinense.Nested analysis of variance,multiple comparison,principal component analysis(PCA),cluster analysis,and correlation analysis were used to explore phenotypic leaf variation among and within populations and potential correlations with geographic and environmental factors.There were significant differences in 17 leaf phenotypic traits among and within populations.The mean phenotypic differentiation coefficient of the 17 traits was 56.34%,and the variation among populations(36.4%)was greater than that within populations(27.2%).The coefficient of variation(CV)of each trait ranged from 4.6 to 23.8%,and the mean was 11.8%.Phenotypic variation of leaves was related to environmental factors such as average annual sunshine hours,average July temperature,and average annual rainfall.The variation changed along gradients of longitude,latitude,and altitude.The PCA clustered the 24 natural populations into four groups.Our study suggests that phenotypic variation in T.sinense occurred primarily among populations,with moderate levels of phenotypic differentiation among populations and low levels of phenotypic variation within populations.The plant’s poor adaptability to the environment is likely an important contributor to its endangerment.Accordingly,conservation strategies are proposed to protect and manage the natural populations of T.sinense.
基金the National Basic Research Program of China(No.2004CB117405)the Key Research Program of Ocean and Fishery Bureau of Guangdong province(No.2001A09)
文摘Mauremys mutica(Cantor,1842)is an endangered species in China.Main phenotypic variations inbody color,body weight,body shape,clutch size,egg size,and hatchling size were revealed betweenthe southern and northern populations.Both populations have the phenomenon of'larger male'sexualsize dimorphism(SSD),especially in the southern population.Furthermore,genetic variations betweenthe two populations were analyzed by RAPD band patterns of 30 random individuals in each population.The average genetic distance was 0.299±0.108 among the samples of two populations.The average ge-netic distance between southern and northern populations was 0.305±0.046.Cluster analysis indicatedthat all the individuals from the southern and northern populations were clustered among themselves toform two distinct clades.A total of 20 population-specific RAPD fragments were scored from 16 primers,and could be used as RAPD markers for distinguishing the southern and the northern population.Basedon the nucleotide sequences of two RAPD markers,two pairs of SCAR primers(SC1-S and SC2-S)weredesigned,which could be used as SCAR markers for the southern population.According to the significantphenotypic and genetic variations,we suggested that the northern population and southern populationmight be considered as two separate taxa,the'northern taxon'and the'southern taxon',and the con-servation should be respectively conducted on the two taxa.
文摘Lespedeza bicolor Turcz is a native shrub in the temperate region of China. Thirteen provenances of L. bicolor were investigated in our study. Morphological diversity among and within provenances were analyzed based on 19 phenotypic traits, including seven vegetative growth characteristics, nine floral traits and three pod characteristics. The coefficient of variation (CV) ranged from 6.4% to 65.4% and the phenotypic differentiation coefficient from 43.3% to 97.3%. Analyses of variance showed that there were extremely significant variations among and within provenances in pod length. Differences in plant height, inter-nodal length, number of branches, leaf width, leaf length and leaf area were not remarkable among provenance, but distinct within provenances. Other traits showed evidence of contrasts. Variation among provenances was the main part of phenotypic variation. Correlation analysis indicated that there were highly significant positive correlations between plant height and other vegetative growth characteristics. Floral traits were not associated with vegetative growth characteristics. The 13 provenances of L. bicolor investigated can be classified into three groups according to a UPGMA cluster analysis.
基金This research was funded by the Universidad Autónoma de Sinaloa(Project PROFAPI 2015/123).
文摘The phenotypic variation and its distribution among species,morphotypes,and among and within populations was estimated in 71 populations pertaining to 15 morphotypes of three domesticated species of Capsicum from Mexico.Collections were made in the states of Sinaloa,Nayarit,Oaxaca,Tabasco,and Yucatán in two agroecosystems:Backyard-garden and monoculture.Fifteen phenotypic characteristics were analyzed through one-way variance analysis and multivariate analyses of principal components analysis(PCA)and hierarchical clustering using Ward’s method.The study was performed in a uniform greenhouse experiment.A high variation was found among and within populations in all the measured characteristics.Of the total variation,13.0%was distributed among species,27.9%among morphotypes,8.1%among populations,and 51.0%within populations.Because plants grew in a uniform environment,these results indicate that the differences observed among and within species,morphotypes,and populations have a genetic basis.Univariate and multivariate analyses clearly differentiated morphotypes,suggesting that the category of morphotypes must be used to nominate the infraspecific variation in the domesticated Capsicum.The principal components analysis identified a total of 15 principal components that contributed to explain the total variation.The first two components explained 59.64%of the total variation and seven components explained more than 90%of the total variation.Among the measured characteristics,number of seed per fruit,weight of the fruit,width of the fruit,length of the fruit,stem diameter,days to flowering,and height of the plant contributed to component 1 variation,whereas width of the leaf,length of the leaf,and number of locules,number of fruits and number of seeds per plant contributed to component 2.The hierarchical clustering separated the populations and the morphotypes in two large different groups.One group consisted of populations collected in monoculture conditions and the other group corresponded to population collected from backyard-garden conditions.The monoculture populations were characterized mainly by their longer,wider,and higher weight fruits,plants were of less height,had smaller stem diameters,and lower number of fruits than the populations collected from the backyard-garden conditions.The backyard-garden populations of the Capsicum annuum and Capsicum frutescens species,considered wild or semi-domesticated,constituted a non-differentiated phenotypic group that does not allow dividing them in different species.
文摘Of the various strategies adopted by an invasive plant species for expanding its niche breadth,phenotypic differentiation(either due to plasticity and/or adaptive evolution) is proven to be the most successful.Lately,we studied the persistence of substantial morpho-functional variations within the individuals of alien invasive plant,Parthenium hysterophorus in Chandigarh,India,through field surveys.Based on observed differences,the individuals were categorized into two morphotypes,PAand PB.PAhad higher leaf area,leaf biomass,and chlorophyll content as compared with PB.However,PBhad a higher stem circumference,stem specific density,twig dry matter content,profuse branching,bigger canopy,and better reproductive output than PA.To substantiate the persistence of intraspecific variations in P. hysterophorus and to deduce the possible genesis of these variations,we propagated both the morphotypes under experimental conditions in winter and summer.Apart from the key morpho-functional differences observed during the field studies,protein and carbohydrate metabolism were studied in leaves and roots of the propagated plants.Differences in plant metabolism were observed only during the early growth period,whereas the morpho-functional traits varied in the mature flowering plants.The effect of growth season was highly significant on all the studied morpho-functional and biochemical parameters(p ≤0.05).Parent morphotypes(P) and interactions between morphotypes and seasons significantly affected several growth parameters(p ≤0.05).The analyses revealed that the contrasting growth conditions at the time of transplantation and early growth may regulate the phenotype of P. hysterophorus.The pattern of intraspecific variations observed during the study is justified to consider morphotype PAas winter biotype and morphotype PBas summer biotype of P. hysterophorus.The study points towards the role of plasticity or a combination of genetic and environmental(G×E) factors in producing the phenotypic variability observed in the population of P. hysterophorus.
基金supported by the Scientifc and Technological Innovation Plan of the Shanghai Science and Technology Committee(20ZR1417000).
文摘Gene expression changes contribute greatly to phenotypic variations in nature.Studying patterns of regulators of gene expression is important to fully understand the molecular mechanism underlying phenotypic variations.In horseshoe bats,the cochleae are fnely tuned to echoes of call frequency.Here,using 2 recently diverged subspecies of the intermediate horseshoe bat(Rhinolophus affnis hainanus and R.a.himalayanus)with great acoustic variations as the system,we aim to explore relative roles of different regulators of gene expression(differential gene expression,alternative splicing(AS)and long non-coding RNAs(lncRNAs))in phenotypic variation with a combination of Illumina short-read and Nanopore long-read RNA-seq data from the cochlea.Compared to R.a.hainanus,R.a.himalayanus exhibited much more upregulated differentially expressed genes(DEGs)and multiple of them may play important roles in the maintenance and damage repair of auditory hair cells.We identifed 411 differentially expressed lncRNAs and their target DEGs upregulated in R.a.himalayanus were also mainly involved in a protective mechanism for auditory hair cells.Using 3 different methods of AS analysis,we identifed several candidate alternatively spliced genes(ASGs)that expressed different isoforms which may be associated with acoustic divergence of the 2 subspecies.We observed signifcantly less overlap than expected between DEGs and ASGs,supporting complementary roles of differential gene expression and AS in generating phenotypic variations.Overall,our study highlights the importance of a combination of short-read and long-read RNA-seq data in examining the regulation of gene expression changes responsible for phenotypic variations.
基金Supported by Department of Biotechnology,New Delhi,India.No.BT/PR26150/MED/12/768/2017.
文摘X-linked adrenoleukodystrophy(X-ALD),an inborn error of peroxisomalβ-oxidation,is caused by defects in the ATP Binding Cassette Subfamily D Member 1(ABCD1)gene.X-ALD patients may be asymptomatic or present with several clinical phenotypes varying from severe to mild,severe cerebral adrenoleukodystrophy to mild adrenomyeloneuropathy(AMN).Although most female heterozygotes present with AMN-like symptoms after 60 years of age,occasional cases of females with the cerebral form have been reported.Phenotypic variability has been described within the same kindreds and even among monozygotic twins.There is no association between the nature of ABCD1 mutation and the clinical phenotypes,and the molecular basis of phenotypic variability in X-ALD is yet to be resolved.Various genetic,epigenetic,and environmental influences are speculated to modify the disease onset and severity.In this review,we summarize the observations made in various studies investigating the potential modifying factors regulating the clinical manifestation of X-ALD,which could help understand the pathogenesis of the disease and develop suitable therapeutic strategies.
文摘The investigation was carried out in focusing the genetic variability for different traits of wheat influenced by heat tolerance mechanism to find out relationships among phenological, physiological and yield contributing traits. Spring wheat cultivar of 25 genotypes were selected and cultivated under late sowing condition at the Regional Wheat Research Institute, Shympur, Rajshahi, Bangladesh from December, 2016 to April, 2017. Significant variability among the genotypes exposed for different traits related to heat tolerance. Results showed that the genotypes G24, G10, G01, G13, G16, G25 and G14 </span><span style="font-family:Verdana;">ranked as better category considering maximum number of traits in mean</span><span style="font-family:Verdana;"> performance indicating their tolerance to heat stress under late sowing condition. Phenotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>) of all traits were greater than those of genotypic variances (<i>σ<sub>g</sub><sup style="margin-left:-6px;">2</sup></i>). The same trends were also found in their co-efficient of variances. The phenotypic co-efficient of variances (PCV) of all traits were greater compare to those of genotypic co-efficient of variances (GCV) and their values were closer to each other. The heading days (HD), canopy temperature at vegetative stage (CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">), canopy temperature at grain filling stage </span><span><span style="font-family:Verdana;">(CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">), biomass, plant height (PH), spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> (SPM), spikelet/spike (SPS), </span></span><span style="font-family:Verdana;">grain/</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">spike (GPS), thousand grain weight (TGW) and yield exhibited higher heritability (<i></span><span style="font-family:Verdana;">h<sub>b</sub><sup style="margin-left:-6px;">2</sup></span><span style="font-family:""><span style="font-family:Verdana;"></i>) estimated under irrigated late sowing (ILS) condition. Under the same ILS condition SPAD, SPM, SPS, GPS, TGW and yield showed moderate to high genetic advance (GA) obtained through computing their mean percentage (%) and the rest traits HD, maturity days (MD), CT</span><sub><span style="font-family:Verdana;">vg</span></sub><span style="font-family:Verdana;">, CT</span><sub><span style="font-family:Verdana;">gf</span></sub><span style="font-family:Verdana;">, biomass, PH and harvest index (HI) exposed smaller genetic advance (% mean). The co-efficient of variation (CV%) of all attributes in all genotypes were significantly lower (1.36</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">- 6.96). Both heritability and genetic advance were found lower for MD, SPAD and HI indicated their non additive genetic effects for </span><span style="font-family:Verdana;">which these traits might not be recommended for selection. However, </span><span style="font-family:Verdana;">spike/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">spikelet/spike, grain/spike, thousand grain weight and yield belonged to </span><span style="font-family:Verdana;">higher heritability and high to moderate genetic advance in mean percentage (%) along with wide genetic variation and lower environmental influence in heat stress situation indicated the most likely heritability due to the effects of additive genes that might be suggested as effective process of selection for these traits in heat stress condition.
基金supported by JSPS RONPAKU Program FY2018,Japan(R11810)Bangladesh University Grants Commission(UGC/SciTech/Agri(Crop-47)-26/2017/4915)。
文摘Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh.It grows well in moderate saline zones with full sunlight.This study presents leaf morphological plasticity in B.sexangula to saline zones.Leaves were sampled from different saline zones and various morphological traits were measured.The results exposed a wide deviations of leaf size parameters:leaf length varied 6.6–17.3 cm;width 2.7–7.8 cm;upper quarter width 2.2–6.5 cm;down quarter width 2.5–7.3 cm;and petiole length 0.17–1.43 cm.Leaf length was significantly larger in fresh water than in other salinity zones,whereas,leaf width,upper and lower leaf quarters were significantly larger in medium saline zone.Leaf shape parameters showed a large variation among saline zones.Leaf base angle was significantly larger in both medium and strong salinity zones.Tip angle was significantly greater in medium salinity zone.Leaf perimeter was significantly larger in fresh water but leaf area was significantly bigger in medium saline zone.Leaf index and specific leaf area were maximum in moderate saline zone.Plasticity index was the highest in moderate saline for almost all the parameters presented.The ordination(PCA)showed clusters of leaf samples although there were some overlap among them which suggested a salt-stress relationship among salinity zones.The results indicate that B.sexangula had a plasticity strategy on leaf morphological parameters to salinity in the Sundarbans.This study will provide basic information of leaf plasticity of this species among saline zones which will help for site selection of coastal planting and will also provide information for policy makers to take necessary steps for its conservation.
文摘Characterization of the reproductive morphology in genus </span><i><span style="font-family:Verdana;">Zingiber</span></i><span style="font-family:Verdana;"> is </span><span style="font-family:Verdana;">still relevant on classical taxonomic studies because most of the species are phenotypically similar and difficult to distinguish in the absence of the flowering stage. Reports mainly derived based on the herbarium collections are insufficient for the detailed morphological review. </span><i><span style="font-family:Verdana;">Zingiber</span></i><span style="font-family:Verdana;"> <i>barbatum</i> </span><span style="font-family:Verdana;">(Wall.) belongs to the genus </span><i><span style="font-family:Verdana;">Zingiber</span></i><span> </span><span style="font-family:Verdana;">and has been neglected for a long time. Existed intraspecific morphological and genetic variations also intricate the description of this sp</span><span style="font-family:Verdana;">ecies. The objective of this study was to characterize the reproductive morphology</span><span style="font-family:Verdana;"> of under-exploited </span><i><span style="font-family:Verdana;">Z.</span></i><span style="font-family:Verdana;"> <i>barbatum</i> </span><span style="font-family:Verdana;">species. The study was done based on the traditional description of morphology and habit of inflorescence and flowers, with a recording of minimum quantitative and qualitative parameters and phenological observation regarding inflorescence life span and duration of blossom. Assessment of reproductive morphology dis</span><span style="font-family:Verdana;">played phenotypic variations regarding inflorescences habit during the growth</span><span style="font-family:Verdana;"> stage and morphological features of the flower. Perhaps, an existed variation was driven by eco-geographical factors resulting in reproductive isolation due to which genetic divergence might occur. The taxonomic affiliation of </span><i><span style="font-family:Verdana;">Z.</span></i><span style="font-family:Verdana;"> <i>barbatum</i> </span><span style="font-family:Verdana;">based on inflorescence habit has been confirmed. This is the first comprehensive report regarding flower biology on </span><i><span style="font-family:Verdana;">Z.</span></i><span style="font-family:Verdana;"> <i>barbatum</i></span><span style="font-family:Verdana;">.
文摘The study investigated genotypic and phenotypic co-efficients of variation, heritability, genetic advance at 5% selection intensity and in percentage of population mean of nine characters (plant height, leaf number, length and width of leaf lamina, number and weight of cormels per plant, weight of corm per plant, dry matter percentage in the tubers and tuber yield per from 14 cultivars of taro [Colocasia esculenta (L.) Schott]). Results indicated highest genotypic co-efficient of variation for dry matter percentage (47.91), which was 95.78% of the phenotypic co-efficient of variation, whereas tuber yield per plant showed the widest range (819.37). Number of cormels per plant and dry matter percentage ehibited considerably higher heritability (84.90% and 91.70%, respectively) and genetic advance (81.19 and 79.00, respectively), indicating the potentiality of selection for improvement of such characters. These two characters were found to be positively correlated to tuber yield per plant. Path analysis revealed that weight of cormels per plant possessed the highest direct effect on tuber yield, indicating the importance of selection based on this character to increase tuber yield per plant.
基金supported by the National Natural Science Foundation of China(3121010390131123007)+2 种基金the National Basic Research Program of China(2013CB835200)the State Key Laboratory of Plant Genomics(2015B0129-01)Liya Wei was supported by the China Postdoctoral Science Foundation(2015M570170)
文摘Transposable elements(TEs), originally discovered in maize as controlling elements, are the main components of most eukaryotic genomes. TEs have been regarded as deleterious genomic parasites due to their ability to undergo massive amplification. However, TEs can regulate gene expression and alter phenotypes. Also, emerging findings demonstrate that TEs can establish and rewire gene regulatory networks by genetic and epigenetic mechanisms. In this review, we summarize the key roles of TEs in fine-tuning the regulation of gene expression leading to phenotypic plasticity in plants and humans, and the implications for adaption and natural selection.
基金supported by the Hebei Science Fund for Distinguished Young Scholars,China(No.D2018503005)the National Key Research and Development Program of China(No.2018YFD0800306)the CAS Preside nfs In ternational Fellowship In itiative Fund(No.2018PB0084).
文摘Understanding the genetic mechanisms for cadmium (Cd) uptake and translocation in common wheat (Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat cultivars was collected from the North China Plain. The cultivars were evaluated in terms of their phenotypic variations in response to Cd stress and subjected to a genome-wide association study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with the phenotypic variations at the seedling stage. Significant phenotypic variations with high heritability were observed among the wheat cultivars exposed to 40 μmol L-1 Cd for the studied traits, including root length (RL), shoot length (SL), root and shoot dry biomasses (RDW and SDW, respectively), root and shoot Cd concentrations (RCD and SCD, respectively), and Cd translocation factor (TF). Mean RCD, SCD, and TF ranged from 1.0 to 33.8, 0.125 to 2.022, and 0.009 to 0.321 mg g-1, respectively. Cluster analysis showed that wheat cultivars with higher RL, SL, RDW, and SDW under Cd stress were able to accumulate more Cd in root, leading to a lower Cd TF. Mixed linear model-based association analysis detected 17 novel significant marker-trait associations (MTAs), four of which were significant at a genome-wide scale. Most of the significant MTAs controlled Cd TF and explained 17.17%–26.47% of the phenotypic variations. Some of the SNP loci were physically close to a reported Cd-related quantitative trait locus or gene on wheat chromosomes. Results of this study provided a list of wheat cultivars with the potential of low Cd accumulation and enriched our knowledge on the genetic basis of Cd uptake and translocation in wheat. Pyramiding breeding of superior alleles detected in this study may additionally reduce Cd accumulation of improved wheat cultivars with excellent agronomic traits.
文摘Fluctuating environments pose tremendous challenges to bacterial populations. It is observed in numerous bacterial species that individual cells can stochastically switch among multiple phenotypes for the population to survive in rapidly changing environments. This kind of phenotypic heterogeneity with stochastic phenotype switching is generally understood to be an adaptive bet-hedging strategy. Mathematical models are essential to gain a deeper insight into the principle behind bet-hedging and the pattern behind experimental data. Traditional deterministic models cannot provide a correct description of stochastic phenotype switching and bet-hedging, and traditional Markov chain models at the cellular level fail to explain their underlying molecular mechanisms. In this paper, we propose a nonlinear stochastic model of multistable bacterial systems at the molecular level. It turns out that our model not only provides a clear description of stochastic phenotype switching and bet-hedging within isogenic bacterial populations, but also provides a deeper insight into the analysis of multidimensional experimental data. Moreover, we use some deep mathematical theories to show that our stochastic model and traditional Markov chain models are essentially consistent and reflect the dynamic behavior of the bacterial system at two different time scales. In addition, we provide a quantitative characterization of the critical state of multistable bacterial systems and develop an effective data-driven method to identify the critical state without resorting to specific mathematical models.
基金Program from Chinese National Basic Research Program(2014CB954203)grants from the National Natural Science Foundation of China(31322010,31270753,31000286)the National Youth Top-notch Talent Support Program to J.D.and Fundamental Research Funds for Central Universities(lzujbky-2012-k23).
文摘Aims More data are needed about how genetic variation(GV)and envi-ronmental factors influence phenotypic variation within the natural populations of long-lived species with broad geographic distribu-tions.To fill this gap,we examined the correlations among envi-ronmental factors and phenotypic variation within and among 13 natural populations of Pinus tabulaeformis consisting of four demo-graphically distinct groups within the entire distributional range.Methods Using the Akaike’s information Criterion(AiC)model,we measured 12 morphological traits and constructed alternative candidate models for the relationships between each morphological trait and key climatic variables and genetic groups.We then compared the AiC weight for each candidate model to identify the best approximating model for ecogeographical variation of P.tabulaeformis.The partitioning of vari-ance was assessed subsequently by evaluating the independent vari-ables of the selected best models using partial redundancy analysis.Important Findings Significant phenotypic variation of the morphological traits was observed both within individual populations and among populations.Variation partition analyses showed that most of the phenotypic variation was co-determined by both GV and climatic factors.GV accounted for the largest proportion of reproductive trait variation,whereas local key climatic factors(i.e.actual evapotranspiration,AET)accounted for the largest proportion of phenotypic variation in the remaining investigated traits.Our results indicate that both genetic divergence and key environmental factors affect the phenotypic variation observed among populations of this species,and that reproductive and vegetative traits adaptively respond differently with respect to local environmental conditions.This partitioning of factors can inform those making predictions about phenotypic variation in response to future changes in climatic conditions(particularly those affecting AET).
文摘Morphological variation of snails from the genus Trochulus is so huge that their taxonomy is unclear. The greatest variability concerns forms hispidus and sericeus/plebeius, which are often considered as separate species. To evidence the species barriers, we carried out crossbreeding ex- periments between these two sympatric morphs. Moreover, we compared the shell morphology of laboratory-bred offspring with their wild parents to test if the variation can be explained by the phenotypic plasticity model. We found that the two Trochulus morphs show no reproductive bar- riers. The fecundity rates, the mean clutch size, and F~ viability observed for all crosses were not significantly different. In hybrid crosses (in F2 generation), we also recorded reproduction compati- bility, similar fecundity, and hatching success as in their parents. Accordingly, phylogenetic ana- lyses revealed the significant grouping of sequences from these different morphs and supported no constrains in reproduction between them. Comparison of shell morphology between wild and laboratory samples showed that various characters appeared highly plastic. The average shell shape of the hispidus morph changed significantly from flat with wide umbilicus to elevated with narrower umbilicus such as in the sericeus/plebeius morph. All these findings indicate that the examined morphs do not represent separate biological species and the evolutionary process is not advanced enough to separate their genetic pool. Therefore, phenotypic plasticity has played a sig- nificant role in the evolution of Trochulus shell polymorphism. The two morphs can evolve inde- pendently in separate phylogenetic lineages under the influence of local environmental conditions.
基金McKenzie Fellowship from University of Melbourne.N.E.L.the Australian Research Council grant DPI80100021a Wolfson Merit Award from the Royal Society.
文摘A fun dame ntal question in biology is how diversity evolves and why some clades are more diverse than others.Phenotypic diversity has often been shown to result from morphological adaptation to different habitats.The role of behavioral interactions as a driver of broadscale phenotypic diversity has received comparatively less attention.Behavioral interactions,however,are a key agent of natural selection.Antagonistic behavioral interactions with predators or with parasites can have significant fitness consequences,and hence act as strong evolutionary forces on the phe no type of species,ultimately gen erating diversity betwee n species of both victims and exploiters.Avian obligate brood parasites lay their eggs in the nests of other species,their hosts,and this behavioral interaction between hosts and parasites is often considered one of the best examples of coevolution in the natural world.In this review,we use the coevolution between brood parasites and their hosts to illustrate the potential of behavioral interactions to drive evolution of phenotypic diversity at different taxonomic scales.We provide a bridge between behavioral ecology and macroevolution by describing how this interaction has increased avian phenotypic diversity not only in the brood parasitic clades but also in their hosts.
基金This research was subsidized by the Hungarian National Research Fund(OTKA T35009,and NWOOTKA N34028),the Hungarian Ministry of Education(FKFP 0187/1990,Istvn Szchenyi Scolarship),and the International Program of the Santa Fe Institute,NM,USA.
文摘Bodies of plants are modularly organized. Development proceeds by adding new modules to open endings with a potential for branching. Each module is autonomous to some extent. Development relies on the self-organized patterns that emerge from the interactions of individual modules. Interactions include both competition and cooperation,and several types of positive and negative feedback loops are involved. Development can be open to external influences, thus enabling the plant to adjust its form to the environment,for example, to the spatial distribution of ecological resources. This paper provides a review on adaptive plasticity in plants.