Genetic parameter evaluation for growth and cold resistance traits of the giant freshwater prawn Macrobrachium rosenbergii

The giant freshwater prawn Macrobrachium rosenbergii distributed from tropical to subtropical regions,is a warm-water species,and its survival temperature is 14-35°C,which greatly limits its culture cycle and culture area in China.Therefore,it is urgent to cultivate a new high quality,high yield variety with improved cold-resistance,but the genetic parameters for cold-resistance traits are unknown in M.rosenbergii.In this study,the cold-resistance of adult M.rosenbergii populations was tested using the indoor artificial cooling method.Individuals were selected from 139 families of Shufeng G3 generation and cultured for 200 days.A linear mixed model was constructed by ASReml-R to evaluate the genetic parameters of the cold-resistance trait(cooling degree hours,CDH)and growth traits(body weight,BW,and body length,BL)based on the restricted maximum likelihood(REML)method.The results show that the heritability of CDH was low(0.12±0.05),while the growth traits(BW and BL)had low to moderate heritability,with 0.20±0.06 for BW and 0.06±0.04 for BL.The phenotypic and genetic correlation between BW and BL was significantly positive,but significantly negative phenotypic and genetic correlations were detected between CDH and BW and between CDH and BL.Furthermore,the analysis of the differences between cold-resistance and phenotypic traits showed that the female reproductive status,exoskeleton hardness and claw number of adult prawns had a great influence on the cold-resistance of M.rosenbergii(P<0.05),indicating that adults with claws and hard exoskeletons are preferred as parents in subsequent breeding selection.The present results can be attributed to the selection and breeding of a new cold-resistant variety of M.rosenbergii.

Remote sensing of quality traits in cereal and arable production systems:A review

Cereal is an essential source of calories and protein for the global population.Accurately predicting cereal quality before harvest is highly desirable in order to optimise management for farmers,grading harvest and categorised storage for enterprises,future trading prices,and policy planning.The use of remote sensing data with extensive spatial coverage demonstrates some potential in predicting crop quality traits.Many studies have also proposed models and methods for predicting such traits based on multiplatform remote sensing data.In this paper,the key quality traits that are of interest to producers and consumers are introduced.The literature related to grain quality prediction was analyzed in detail,and a review was conducted on remote sensing platforms,commonly used methods,potential gaps,and future trends in crop quality prediction.This review recommends new research directions that go beyond the traditional methods and discusses grain quality retrieval and the associated challenges from the perspective of remote sensing data.

Genome-wide association study identifies 12 new genetic loci associated with growth traits in pigs

Growth traits are among the most important economic traits in pigs and are regulated by polygenes with complex regulatory mechanisms.As the major indicators of growth performance,the backfat thickness(BFT),loin eye area(LEA),and days to 100 kg(D100)traits are commonly used to the genetics improvement in pigs.However,the available genetic markers for these traits are limited.To uncover novel loci and candidate genes associated with growth performance,we collected the phenotypic information of BFT,LEA,and D100 in 1,186 pigs and genotyped all these individuals using the Neogen GGP porcine 80K BeadChip.We performed a genome-wide association study(GWAS)using 4 statistical models,including mixed linear models(MLM),fixed and random model circulating probability unification(FarmCPU),settlement of MLM under progressively exclusive relationships(SUPER),Bayesian-information and linkage-disequilibrium Iteratively nested keyway(Blink),and identified 5,3,and 6 high-confidence single nucleotide polymorphisms(SNPs)associated with BFT,LEA,and D100,respectively.Variant annotation and quantitative trait locus(QTL)mapping analysis suggested that6 genes(SKAP2,SATB1,PDE7B,PPP1R16B,WNT3,and WNT9B)were potentially associated with growth performance in pigs.Transcriptome analysis suggested that the expression of Src Kinase Associated Phosphoprotein 2(SKAP2)was higher in prenatal muscles than in postnatal muscles,and the expression of Phosphodiesterase 7B(PDE7B)continuously increased during the prenatal stages and gradually decreased after birth,implying their potential roles in prenatal skeletal muscle development.Overall,this study provides new candidate loci and genes for the genetic improvement of pigs.

Comparative Preliminary Evaluation of Agronomic and Quality Traits of New"Zhongtang"Superior Lines

[Objectives]Sugarcane is the most significant sugar cash crop in the tropical and subtropical regions of China.However,it is notable for its narrow genetic basis,limited trait improvement,weak adaptability of varieties,and poor planting efficiency.In order to accelerate the process of sugarcane variety replacement and expand the basis of genetic variation,interspecific hybridization and multiple mutagenesis are the most effective methods for obtaining new sugarcane varieties.The evaluation and identification of phenotypic traits of germplasm represents a significant analytical method.The"Zhongtang"series of sugarcane varieties is distinguished by its high yield and high sugar content.New sugarcane germplasms with excellent agronomic and quality traits can be identified and developed as breeding parents and new breeding lines through comprehensive evaluation of the existing germplasm.[Methods]A total of 181 new lines were selected through genetic origin and orientation,and evaluated and appraised for growth,yield,and economic characteristics.The data on 6 important agronomic and quality traits,including tillering,initial plant height,plant height,stem diameter,number of effective stems,and brix at maturity,were used to discover superior lines.These traits were evaluated during the two production seasons of the participant lines.[Results]A comprehensive evaluation of seedling growth traits and economic traits at maturity of the experimental lines identified 30 excellent new germplasms of sugarcane.Among the selected lines,1501 and 1701 exhibited superior agronomic and quality traits,rendering them suitable as parental lines for sugarcane breeding or breeding as new varieties.[Conclusions]The exemplary results obtained in this study provide a solid foundation for the improvement of sugarcane germplasm,with the goal of enhancing quality and efficiency.These findings are of great scientific and practical significance to the study of sugarcane yield and sugar-related genes,as well as the exploration of the evaluation and utilization of sugarcane germplasm resources.

Genetic analysis and candidate gene identification of salt tolerancerelated traits in maize

Soil salinization poses a threat to maize production worldwide,but the genetic mechanism of salt tolerance in maize is not well understood.Therefore,identifying the genetic components underlying salt tolerance in maize is of great importance.In the current study,a teosinte-maize BC2F7 population was used to investigate the genetic basis of 21 salt tolerance-related traits.In total,125 QTLs were detected using a high-density genetic bin map,with one to five QTLs explaining 6.05–32.02%of the phenotypic variation for each trait.The total phenotypic variation explained(PVE)by all detected QTLs ranged from 6.84 to 63.88%for each trait.Of all 125 QTLs,only three were major QTLs distributed in two genomic regions on chromosome 6,which were involved in three salt tolerance-related traits.In addition,10 pairs of epistatic QTLs with additive effects were detected for eight traits,explaining 0.9 to 4.44%of the phenotypic variation.Furthermore,18 QTL hotspots affecting 3–7 traits were identified.In one hotspot(L5),a gene cluster consisting of four genes(ZmNSA1,SAG6,ZmCLCg,and ZmHKT1;2)was found,suggesting the involvement of multiple pleiotropic genes.Finally,two important candidate genes,Zm00001d002090 and Zm00001d002391,were found to be associated with salt tolerance-related traits by a combination of linkage and marker-trait association analyses.Zm00001d002090 encodes a calcium-dependent lipid-binding(CaLB domain)family protein,which may function as a Ca^(2+)sensor for transmitting the salt stress signal downstream,while Zm00001d002391 encodes a ubiquitin-specific protease belonging to the C19-related subfamily.Our findings provide valuable insights into the genetic basis of salt tolerance-related traits in maize and a theoretical foundation for breeders to develop enhanced salt-tolerant maize varieties.

Effects of wind speed,underlying surface,and seed morphological traits on the secondary seed dispersal in the Tengger Desert,China

The maintenance of sand-fixing vegetation is important for the stability of artificial sand-fixing systems in which seed dispersal plays a key role.Based on field wind tunnel experiments using 11 common plant species on the southeastern edge of the Tengger Desert,China,we studied the secondary seed dispersal in the fixed and semi-fixed sand dunes as well as in the mobile dunes in order to understand the limitations of vegetation regeneration and the maintenance of its stability.Our results indicated that there were significant variations among the selected 11 plant species in the threshold of wind speed(TWS).The TWS of Caragana korshinskii was the highest among the 11 plant species,whereas that of Echinops gmelinii was the lowest.Seed morphological traits and underlying surface could generally explain the TWS.During the secondary seed dispersal processes,the proportions of seeds that did not disperse(no dispersal)and only dispersed over short distance(short-distance dispersal within the wind tunnel test section)were significantly higher than those of seeds that were buried(including lost seeds)and dispersed over long distance(long-distance dispersal beyond the wind tunnel test section).Compared with other habitats,the mobile dunes were the most difficult places for secondary seed dispersal.Buried seeds were the easiest to be found in the semi-fixed sand dunes,whereas fixed sand dunes were the best sites for seeds that dispersed over long distance.The results of linear mixed models showed that after controlling the dispersal distance,smaller and rounder seeds dispersed farther.Shape index and wind speed were the two significant influencing factors on the burial of seeds.The explanatory power of wind speed,underlying surface,and seed morphological traits on the seeds that did not disperse and dispersed over short distance was far greater than that on the seeds that were buried and dispersed over long distance,implying that the processes and mechanisms of burial and long-distance dispersal are more complex.In summary,most seeds in the study area either did not move,were buried,or dispersed over short distance,promoting local vegetation regeneration.

Variation Characteristics of Root Traits of Different Alfalfa Cultivars under Saline-Alkaline Stress and their Relationship with Soil Environmental Factors

Soil salinization is the main factor that threatens the growth and development of plants and limits the increase of yield.It is of great significance to study the key soil environmental factors affecting plant root traits to reveal the adaptation strategies of plants to saline-alkaline-stressed soil environments.In this study,the root biomass,root morphological parameters and root mineral nutrient content of two alfalfa cultivars with different sensitivities to alkaline stress were analyzed with black soil as the control group and the mixed saline-alkaline soil with a ratio of 7:3 between black soil and saline-alkaline soil as the saline-alkaline treatment group.At the same time,the correlation analysis of soil salinity indexes,soil nutrient indexes and the activities of key enzymes involved in soil carbon,nitrogen and phosphorus cycles was carried out.The results showed that compared with the control group,the pH,EC,and urease(URE)of the soil surrounding the roots of two alfalfa cultivars were significantly increased,while soil total nitrogen(TN),total phosphorus(TP),organic carbon(SOC),andα-glucosidase activity(AGC)were significantly decreased under saline-alkaline stress.There was no significant difference in root biomass and root morphological parameters of saline-alkaline tolerant cultivar GN under saline-alkaline stress.The number of root tips(RT),root surface area(RS)and root volume(RV)of AG were reduced by 61.16%,44.54%,and 45.31%,respectively,compared with control group.The ratios of K^(+)/Na^(+),Ca^(2+)/Na^(+)and Mg^(2+)/Na^(+)of GN were significantly higher than those of AG(p<0.05).The root fresh weight(RFW)and dry weight(RDW),root length(RL),RV and RT of alfalfa were positively regulated by soil SOC and TN,but negatively regulated by soil pH,EC,and URE(p<0.01).Root Ca^(2+)/Na+ratio was significantly positively correlated with soil TN,TP and SOC(p<0.01).The absorption of Mg and Ca ions in roots is significantly negatively regulated by soilβ-glucosidase activity(BGC)and acid phosphatase activity(APC)(p<0.05).This study improved knowledge of the relationship between root traits and soil environmental factors and offered a theoretical framework for elucidating how plant roots adapt to saline-alkaline stressed soil environments.

Species’ geographical range, environmental range and traits lead to specimen collection preference of dominant plant species of grasslands in Northern China

Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate.

The Impact of Big Five Personality Traits on Older Europeans’ Physical Health

Investigating the role of Big Five personality traits in relation to various health outcomes has been extensively studied. The impact of “Big Five” on physical health is here explored for older Europeans with a focus on examining age groups differences. The study sample included 378,500 respondents derived from the seventh data wave of Survey of Health, Aging and Retirement in Europe (SHARE). The physical health status of older Europeans was estimated by constructing an index considering the combined effect of well-established health indicators such as the number of chronic diseases, mobility limitations, limitations with basic and instrumental activities of daily living, and self-perceived health. This index was used for an overall physical health assessment, for which the higher the score for an individual, the worst health level. Then, through a dichotomization process applied to the retrieved Principal Component Analysis scores, a two-group discrimination (good or bad health status) of SHARE participants was obtained as regards their physical health condition, allowing for further con-structing logistic regression models to assess the predictive significance of “Big Five” and their protective role for physical health. Results showed that neuroti-cism was the most significant predictor of physical health for all age groups un-der consideration, while extraversion, agreeableness and openness were not found to significantly affect the self-reported physical health levels of midlife adults aged 50 up to 64. Older adults aged 65 up to 79 were more prone to open-ness, whereas the oldest old individuals aged 80 up to 105 were mainly affected by openness and conscientiousness. .

Analyses of Chicken Tenderness Traits Based on Transcriptome Sequencing

The calpain system is ubiquitous in cells, mainly comprising calpains and calpain inhibitors, and is a widespread calcium-dependent cysteine protease in organisms that is involved in many cellular processes such as muscle degradation in vivo and affects the tenderness of meat after animal slaughter. The study found 128 DEGs that probably regulated tenderness traits were selected from 16 significantly enriched GO terms by transcriptome sequencing analysis, and found that the developmental changes in the expression levels of the CAPN1 gene in the pectoral and leg muscles were significantly positively correlated ( P <0.05) with the cumulative growth values of live weight and comb weight. The developmental changes in the expression levels of the CAST gene in the pectoral and leg muscles were not significantly correlated with the cumulative growth values of live weight and comb weight. Our results helped demonstrate the potential molecular mechanisms of tenderness in chickens and provide valuable information for chicken breeding.

Effects of Seeding Date and Density on Yield and Agronomic Traits of Millet : A Case Study of Wangu 098 Variety of Millet

[Objectives]To find out a suitable cultivation technique of Wangu 098 in Nanyang area,speed up the popularization,demonstration and application of Wangu 098,and provide a theoretical and practical basis for adjusting the planting structure and realizing the matching of improved varieties and methods.[Methods]The new self-bred millet variety Wangu 098 was used as the material,and the two-factor split zone experimental design was adopted.The effects of different sowing dates and densities on the yield,growth period and agronomic characters of millet were studied.[Results]The interaction of seeding date and density had a great effect on the yield and plant traits of millet.Millet yield was significantly and positively correlated with plant height,panicle length,single panicle weight,panicle grain weight and tiller number.[Conclusions]The reasonable combination of seeding date and density could give full play to the yield potential of millet.According to the experimental results and cultivation experience,the suitable seeding date of millet in Nanyang area is in the first and middle ten days of June,and the best density is about 750000 plants/ha.However,after June 30,the seeding millet did not tiller,so the density should be increased to more than 900000 plants/ha to obtain higher yield.In terms of cultivation and management,timely seeding,reasonable close planting,and coordination of vegetative growth and reproductive growth can make the plant tall and strong,panicle long and thick,and improve the yield of millet.

Host plant traits play a crucial role in shaping the composition of epiphytic microbiota in the arid desert,Northwest China

Phyllosphere microorganisms are a crucial component of environmental microorganisms,highly influenced by host characteristics,and play a significant role in plant health and productivity.Nonetheless,the impact of host characteristics on shaping phyllosphere microbial communities of plants with different life forms remains ambiguous.Utilizing high-throughput sequencing technology,this study analyzed the diversity and community composition of phyllosphere epiphytic microorganisms(e.g.,bacteria and fungi)of various plant life forms in the hinterland of the Gurbantunggut Desert,Northwest China.Functional annotation of prokaryotic taxa(FAPROTAX)and fungi function guild(FUNGuild)were employed to assess the ecological functions of microorganisms and to investigate the role of stochastic and deterministic processes in shaping phyllosphere microbial communities.Result showed a diverse array of phyllosphere epiphytic microorganisms in the desert plants,with Proteobacteria,Cyanobacteria,and Actinobacteriota dominating bacterial community,while Ascomycota and Basidiomycota were prevalent in fungal community.Comparison across different plant life forms highlighted distinct microbial communities,indicating strong filtering effects by plant characteristics.FAPROTAX prediction identified intracellular parasites(accounting for 27.44%of bacterial community abundance),chemoheterotrophy(10.12%),and phototrophy(17.41%)as the main functions of epiphytic bacteria on leaves of different life form plants.FUNGuild prediction indicated that phyllosphere epiphytic fungi primarily served as Saprotrophs(81.77%),Pathotrophs(17.41%),and Symbiotrophs(0.82%).Co-occurrence network analysis demonstrated a predominance of positive correlations among different microbial taxa.Raup-Crick dissimilarity index analysis revealed that deterministic processes predominantly influenced phyllosphere bacterial and fungal community assembly.Variance partitioning analysis and random forest modeling suggested that plant leaf functional traits significantly impacted both bacterial and fungal community composition,with fungal community composition showing a closer association with leaf nutrients and physiology compared with bacterial community composition.The distinct responses of bacterial and fungal communities to plant traits were attributed to the differing properties of bacteria and fungi,such as bacteria having higher potential dispersal rates and broader ecological niches than fungi.Overall,the results indicate that phyllosphere bacterial and fungal communities undergo similar community assembly processes,with fungi being more influenced by plant characteristics than bacteria.These findings offer novel insights into the ecology of phyllosphere microbial communities of desert plants.

An Expanded View of Complex Traits:From Polygenic to Omnigenic

A central goal of genetics is to understand the links between genetic variation and disease.Intuitively,one might expect diseasecausing variants to cluster into key pathways that drive disease etiology.But for complex traits,association signals tend to be spread across most of the genome-including near many genes without an obvious connection to disease.

Genome-wide association study of 23 f lowering phenology traits and 4 f loral agronomic traits in tree peony (Paeonia section Moutan DC.) reveals five genes known to regulate f lowering time

Tree peony is a unique traditional f lower in China,with large,fragrant,and colorful f lowers.However,a relatively short and concentrated f lowering period limits the applications and production of tree peony.A genome-wide association study(GWAS)was conducted to accelerate molecular breeding for the improvement of f lowering phenology traits and ornamental phenotypes in tree peony.A diverse panel of 451 tree peony accessions was phenotyped for 23 f lowering phenology traits and 4 f loral agronomic traits over 3 years.Genotyping by sequencing(GBS)was used to obtain a large number of genome-wide single-nucleotide polymorphisms(SNPs)(107050)for the panel genotypes,and 1047 candidate genes were identified by association mapping.Eighty-two related genes were observed during at least 2 years for f lowering,and seven SNPs repeatedly identified for multiple f lowering phenology traits over multiple years were highly significantly associated with five genes known to regulate f lowering time.We validated the temporal expression profiles of these candidate genes and highlighted their possible roles in the regulation of f lower bud differentiation and f lowering time in tree peony.This study shows that GWAS based on GBS can be used to identify the genetic determinants of complex traits in tree peony.The results expand our understanding of f lowering time control in perennial woody plants.Identification of markers closely related to these f lowering phenology traits can be used in tree peony breeding programs for important agronomic traits.

Resequencing of sweetpotato germplasm resources reveals key loci associated with multiple agronomic traits

Sweetpotato is an important crop that exhibits hexaploidy and high heterozygosity,which limits gene mining for important agronomic traits.Here,314 sweetpotato germplasm resources were deeply resequenced,and 4599509 SNPs and 846654 InDels were generated,among which 196124 SNPs were nonsynonymous and 9690 InDels were frameshifted.Based on the Indels,genome-wide marker primers were designed,and 3219 of 40366 primer pairs were selected to construct the core InDel marker set.The molecular ID of 104 sweetpotato samples verified the availability of these primers.The sweetpotato population structures were then assessed through multiple approaches using SNPs,and diverse approaches demonstrated that population stratification was not obvious for most Chinese germplasm resources.As many as 20 important agronomic traits were evaluated,and a genome-wide association study was conducted on these traits.A total of 19 high-confidence loci were detected in both models.These loci included several candidate genes,such as IbMYB1,IbZEP1,and IbYABBY1,which might be involved in anthocyanin metabolism,carotenoid metabolism,and leaf morphogenesis,respectively.Among them,IbZEP1 and IbYABBY1 were first reported in sweetpotato.The variants in the promoter and the expression levels of IbZEP1 were significantly correlated with f lesh color(orange or not orange)in sweetpotato.The expression levels of IbYABBY1 were also correlated with leaf shape.These results will assist in genetic and breeding studies in sweetpotato.

Large-scale population structure and genetic architecture of agronomic traits of garlic

Garlic,an asexually propagated crop,is the second important bulb crop after the onion and is used as a vegetable and medicinal plant.Abundant and diverse garlic resources have been formed over thousands of years of cultivation.However,genome variation,population structure and genetic architecture of garlic agronomic traits were still not well elucidated.Here,1100258 single nucleotide polymorphisms(SNPs)were identified using genotyping-by-sequencing in 606 garlic accessions collected from43 countries.Population structure,principal component and phylogenetic analysis showed that these accessions were divided into five subpopulations.Twenty agronomic traits,including above-ground growth traits,bulb-related and bolt-related traits in two consecutive years were implemented in a genome-wide association study.In total,542 SNPs were associated with these agronomic traits,among which 188 SNPs were repeatedly associated with more than two traits.One SNP(chr6:1896135972)was repeatedly associated with ten traits.These associated SNPs were located within or near 858 genes,56 of which were transcription factors.Interestingly,one non-synonymous SNP(Chr4:166524085)in ribosomal protein S5 was repeatedly associated with above-ground growth and bulb-related traits.Additionally,gene ontology enrichment analysis of candidate genes for genomic selection regions between complete-bolting and non-bolting accessions showed that these genes were significantly enriched in‘vegetative to reproductive phase transition of meristem’,‘shoot system development’,‘reproductive process’,etc.These results provide valuable information for the reliable and efficient selection of candidate genes to achieve garlic genetic improvement and superior varieties.

Genetic dissection of crown root traits and their relationships with aboveground agronomic traits in maize

The crown root system is the most important root component in maize at both the vegetative and reproductive stages. However, the genetic basis of maize crown root traits(CRT) is still unclear, and the relationship between CRT and aboveground agronomic traits in maize is poorly understood. In this study, an association panel including 531 elite maize inbred lines was planted to phenotype the CRT and aboveground agronomic traits in different field environments. We found that root traits were significantly and positively correlated with most aboveground agronomic traits, including flowering time, plant architecture and grain yield. Using a genome-wide association study(GWAS)coupled with resequencing, a total of 115 associated loci and 22 high-confidence candidate genes were identified for CRT. Approximately one-third of the genetic variation in crown root was co-located with 46 QTLs derived from flowering and plant architecture. Furthermore, 103 (89.6%) of 115 crown root loci were located within known domestication-and/or improvement-selective sweeps, suggesting that crown roots might experience indirect selection in maize during domestication and improvement. Furthermore, the expression of Zm00001d036901, a high-confidence candidate gene, may contribute to the phenotypic variation in maize crown roots, and Zm00001d036901 was selected during the domestication and improvement of maize. This study promotes our understanding of the genetic basis of root architecture and provides resources for genomics-enabled improvements in maize root architecture.

Genetic relatedness and association mapping of horticulturally valuable traits for the Ceiba plants using ddRAD sequencing

Ceiba species have high ornamental value and are widely cultivated in tropical regions.However,genetic background of cultivated Ceiba plants remains unclear.To understand the genetic relatedness of cultivated Ceiba plants and genetic basis of key horticultural traits,here we explored the genetic relatedness of 153 accessions of Ceiba plants cultivated in Southern China and identified SNPs associated with five horticultural traits,based on 11704 SNPs derived from double-digest restriction-site associated DNA sequencing(ddRAD-seq).Clustering analysis revealed that these accessions were composed of three groups:C.speciosa group,C.insignis group,and hybrid group.The GWAS identified two,four,two,three,and four SNPs related to petal color,petal striation number,flowering time,trunk shape,and prickles on the trunk and branches,respectively.One to two candidate genes were found near the SNPs strongly associated with these traits.This study revealed the genetic relatedness in the Ceiba plants cultivated in Southern China and presented the first GWAS analysis for five horticultural traits for them,laying a foundation for phenotype-related marker selection and molecular breeding.

Genome-wide association and linkage mapping strategies reveal the genetic loci and candidate genes of important agronomic traits in Sichuan wheat

Increasing wheat yield is a long-term goal for wheat breeders around the world.Exploiting elite genetic resources and dissecting the genetic basis of important agronomic traits in wheat are the necessary methods for high-yield wheat breeding.This study evaluated nine crucial agronomic traits found in a natural population of 156 wheat varieties and77 landraces from Sichuan,China in seven environments over two years.The results of this investigation of agronomic traits showed that the landraces had more tillers and higher kernel numbers per spike (KNS),while the breeding varieties had higher thousand-kernel weight (TKW) and kernel weight per spike (KWS).The generalized heritability (H2) values of the nine agronomic traits varied from 0.74 to 0.95.Structure analysis suggested that the natural population could be divided into three groups using 43 198 single nucleotide polymorphism (SNP) markers from the wheat 55K SNP chip.A total of 67 quantitative trait loci (QTLs) were identified by the genome-wide association study (GWAS) analysis based on the Q+K method of a mixed linear model.Three important QTLs were analyzed in this study.Four haplotypes of QFTN.sicau-7BL.1 for fertile tillers number (FTN),three haplotypes of QKNS.sicau-1AL.2 for KNS,and four haplotypes of QTKW.sicau-3BS.1 for TKW were detected.FTN-Hap2,KNS-Hap1,and TKW-Hap2 were excellent haplotypes for each QTL based on the yield performance of 42 varieties in regional trials from 2002 to 2013.The varieties with all three haplotypes showed the highest yield compared to those with either two haplotypes or one haplotype.In addition,the KASP-AX-108866053 marker of QTL QKNS.sicau-1AL.2 was successfully distinguished between three haplotypes(or alleles) in 63 varieties based on the number of kernels per spike in regional trials between 2018 and 2021.These genetic loci and reliable makers can be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of wheat yield.

Geographical differences of leaf traits of the endangered plant Litsea coreana Levl.var.sinensis and its relationship with climate

Seventeen morphological and anatomical characteristics of the leaves were selected from five natural populations to explore the variation in leaf traits of Lits ea core ana var.sinensis and the effects of geographical environment on these variations.Nested analysis of variance,multiple comparisons,principal component analysis(PCA),and correlation analysis were conducted to explore the variations within and between populations and their correlation with geographical and climatic factors.Significant differences in the 17 leaf traits were observed within and among populations.On average,the relative contribution of within population variation to total variation was 24.8%,which was lower than among population variation(54.6%).The average differentiation coefficient of the traits was 65.8%,and the average coefficient of variation 11.8%,ranging from6.7%for main vein thickness to 21.4%for petiole length.The PC A results showed that morphological characteristics were divided into two categories,and the level of variation was greater than that of leaf anatomy.Most of the leaf traits were significantly correlated with geography and climate and showed a gradual variation with longitude,latitude,and altitude.In areas with high temperatures,less rainfall,and strong seasonal rainfall,the leaves are larger,longer and thicker.This study shows that variations in leaf traits of L.coreana var.sinensis mainly come from variations among populations.The level of trait differentiation among populations is high and the level of variation within populations low.These findings help further understand leaf morphological characteristics of this species and can provide a valuable reference for the protection and sustainable utilization of this natural resource.