A test of genetic divergence of a bird existing in the Sichuan Basin and its surrounding mountain ranges

Island ecosystems,serving as natural laboratories,facilitate geographical isolation,ecological specialization,and species divergence.The Sichuan Basin,surrounded by mountain ranges,represents a typical continental island due to its marked environmental spatial heterogeneity.This heterogeneity may contribute to geographical isolation and habitat heterogeneity,resulting in genetic divergence within populations.Therefore,we used the White-browed Laughingthrush(Garrulax sannio)as a model specimen to investigate the genetic divergence in the Sichuan Basin and its surrounding mountain ranges,given its presence in various habitats within and beyond this basin.Employing a RAD-seq dataset of 140 G.sannio individuals from 17 distinct ecological zones in the Sichuan Basin and its surrounding mountain ranges,we conducted PCA,population structure analysis,phylogenetic tree construction,and gene flow analysis to comprehensively analyze G.sannio groups.Additionally,in conjunction with geographical and ecological data,we performed isolation by distance,isolation by environment,PCA,and latent factor mixed model analysis to identify factors influencing the genetic divergence among these G.sannio groups.In summary,the 17 G.sannio groups were categorized into high-elevation,medium-elevation,and lowelevation groups.Genetic divergence in G.sannio may be attributed to both geographical distance and key ecological factors,particularly elevation and key climatic variables.Notably,the high-elevation group exhibited a greater number of SNPs and selected genes associated with the key ecological factors compared to the lowelevation group.The ADCY9 gene and several associated key pathways were identified as crucial elements driving ecological adaptation(elevation and key climatic variables)in the high-elevation group.Furthermore,climate changes during the glacial cycles may have facilitated gene flow among these groups residing in the Sichuan Basin and its surrounding mountain ranges.Our findings provide evidence of genetic divergence in G.sannio influenced by the geographical distance and key ecological factors between the Sichuan Basin and its surrounding mountain ranges.These results lay the groundwork for future research on the molecular systematics of continental islands.

Evaluation of Genetic Divergence in Various Potato Genotypes Grown in Bangladesh through Different Traits Assessment

The goal of the study was to quantify the genetic diversity of different potato varieties. Five groups were named to classify the 25 genres of potatoes as: Cluster I (Lalpakri, Diamond), Cluster II (Hagrai, Green Mountain, G.M.O., Elvera), Cluster III (Atlantic, Shepody, Raja, Fundy, Multa, Granulla, Shibilati, Japanese Red), Cluster IV (Atlas, Brondy, Yucon Gold, Monona, Petrones, Cheroki), and Cluster V (Calwhite, Prelude, Allblue, Russet, Burbank, TPS-67). The highest and lowest genotypes are found in Clusters III and I, respectively. The two groups’ maximum inter-cluster distance (the cluster’s distance between them) demonstrates the enormous diversity between Clusters II & III. Cluster III had the greatest intra-cluster distance (distance within a set), whereas Cluster V had the smallest. In most cases, the distance between gaps was more significant than the distance within the holes, showing greater genetic diversity between different groups’ genotypes. The highest, second highest, and third highest eigenvalues, accompanying the positive canonical values for Vectors I and II of three characteristics: average tuber weight in each plant, the tubers number in each plant, and the eyes number in each tuber, showed the most outstanding contribution to the complete difference between genotypes. Of the nine features, the smaller leaves number in each plant, the shorter plant height, the more minor genotypes, the fewer eyes per tube generated from Cluster I, the maximum height of the plants, the high-quality tubers in each plant, the tubers number in each plant, the fresh weight in each plant, and the leaf number in each plant from Cluster II could be chosen in the role of parents in this program for hybridization. Given the size of the genetic distance, the various characteristics that contribute to the overall difference, and the average population size, Hagrai, Green Mountain, O.M.G., Elvera Cluster II and Cluster I, Lalpakri, and Diamond genotypes can be regarded as parents of hybridization programs in the future. Thus, producers can get guidance to enhance genetic diversity by selecting materials from different relatives and reducing their vulnerability to diseases and climate change.

Genetic variability and divergence studies in pod and seed traits of Pongamia pinnata(L.) Pierre., accessions in Bay Islands

In this study, we assessed the variability in pod, seed traits and oil content of 24 accessions of Pongamia pinnata collected from different parts of the Andaman and Nicobar Islands, India. The experiment was conducted at the Central Agricultural Research Institute, Port Blair during 2010 to 2011. The variability studies for pod and seed traits revealed that, the accession CPT-6 collected from New Wandoor in South Andaman recorded the maximum values for eight traits viz. pod length （75.51 mm）, pod width （34.62 mm）, pod thickness （17.55 mm）, 100 pod weight （770.33 g）, seed width （21.23 mm）, 100 seed weight （377.00 g）, oil percentage （43.92%） and germination percentage （94.7%）. However, the maximum seed length （26.46 mm） was recorded from CPT 2 and the maximum pod-seed ratio was obtained from CPT 13 and CPT 4 （2.50 and 2.44 respectively）. The phenotypic and genotypic coefficients of variations were also close to each other for all traits, but the 100 pod and seed weight exhibited higher phenotypic and genotypic coefficient of variation than the other traits. Estimates of broad sense heritability ranged from 0.30 （for seed length） to 0.95 （pod length） and genetic ad- vance as percent of the mean ranged between 11.66% and 57.40% with seed length giving the lowest value and 100 pod weight giving the high- est value. Both the phenotypic and genotypic correlation between pod length, pod width, pod thickness, 100 pod weight, seed width and 100 seed weight and between pod thickness, 100 pod weight, seed width, 100 seed weight and germination percentage were found to be strong. On the basis of non hierarchical Euclidian cluster analysis, 24 accessions were grouped into six clusters. The maximum numbers of seven accessions were included in cluster VI. The maximum intra cluster distance （10.238）shown by cluster VI and the maximum inter cluster distance （17.021） between V and HI followed by III and II （15.942）. Among the six clus- ters formed the cluster III recorded maximum oil percentage, 100 pod weight, 100 seed ,weight, pod length, pod thickness, pod width, seed width and. germination percentage, while cluster V recorded maximum pod seed ratio and germination percentage. The present findings suggest that the crossing between accessions of cluster V and cluster III will result in a wide spectrum of variability in subsequent generations.

Genetic and morphological divergence in the purple sea urchin Paracentrotus lividus(Echinodermata,Echinoidea)across the African Mediterranean coast

The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tunisian Strait on gene flow disruption in this highly dispersive echinoid species. For this purpose, patterns of morphological and genetic variation were assessed among its populations from the western and eastern Mediterranean coasts. A total of 302 specimens from seven Tunisian sites were collected and examined for morphometric variability at twelve morphometric traits. Concordant results, inferred from CDA（canonical discriminant analyses）, pairwise NPMANOVA（non parametric multivariate analysis of variance） comparisons and MDS（multidimensional scaling） plot, unveiled significant inter-population differences in the measured traits among the studied populations. Furthermore, the combined use of the one way ANOSIM（analysis of similarities） and the Discriminant/Hotelling analysis allowed unravelling two morphologically differentiated groups assigned to both western and eastern Mediterranean basins. The SIMPER（similarity percentages） routine analysis showed that total dry weight, test diameter and spine length were major contributors to the morphometric separation between locations and between groups. Pattern of phenotypic divergence discerned in P. lividus across the Siculo-Tunisian Strait is interestingly in congruence with that inferred from the genetic investigation of the purple sea urchin populations from the same region based on the analysis of the mt DNA COI（cytochrome oxidase I） gene in 314 specimens from nineteen locations covering a wider geographic transect, streching westward to the Algerian coast and eastward to the Libyan littoral. The specific haplotypic composition characterizing each Mediterranean basin,as inferred from the minimum spanning network, confirmed the geographic partioning of genetic variation, as revealed by F-statistics and AMOVA（analysis of molecular variance） analyses, yielding significant genetic differentiation between eastern and western Mediterranean populations. The newly detected phylogeographic patterns, observed for the first time in P. lividus throughout the explored distribution range, suggest the involvement of different biotic and abiotic processes in shaping such variation, and provide evidence that a large and geographically exhaustive dataset is necessary to unveil phylogeographic structure within widespread marine species, previously cathegorized as panmictic in part of their distribution range.

Genetic divergence for growth and wood parameters in different clones of Dalbergia sissoo Roxb

The wood analysis for different parameters was carried out in a clonal seed orchard ofDalbergia sissoo Roxb. established during 1997 at Hoshiarpur, Punjab, India. Twelve clones with higher index value were subjected to Euclidean Cluster Analysis based on wood and growth parameters to group into seven clusters. Cluster I and II contained four and three clones, respectively, and remaining clusters bad just one clone each. Clone originated from Barielly, Uttar Pradesh of cluster VII was found to be the most divergent clone. Cluster II with three clones main- tained greater inter cluster distance with other clusters. The divergence analysis has confirmed that the clones planted in the clonal seed orchard are sufficiently divergent and seed harvested from the orchard would maintain high diversity.

D2 analysis for estimating genetic divergence in different clones of Dalbergia sissoo

Genetic divergence was studied in selected 36 genotypes of Dalbergia sissoo Roxb. on the basis of seven morphological parameters. The divergence among genotypes was estimated by Mahalanobis method and genotypes were grouped into clusters by Tocher＇s method. All the genotypes were classified into seven distinct clusters on the basis of seven morphological traits. Cluster 1 was the largest with 25 genotypes followed by Cluster 2 （four genotypes）. Cluster 3, 5, 6 and 7 were the divergent clusters. The D2 analysis revealed that D2 value （39.42） between clone 5040 and clone 201 was recorded maximum. The intra-cluster distance ranged from 0.00 （Cluster 3, 5, 6 and 7） to 3.89 （Cluster 1）, the Cluster 3 （clone 33） was the most divergent cluster with maximum inter cluster distance （13.97） with the Cluster 7. By the divergence analysis, the parents for hybridization from diverse clusters could be selected for heterotic hybrids.

Genetic Differentiation Among Populations of Octopus minor Based on Simple Sequence Repeats Mined from Transcriptome Data

Octopus minor(Sasaki 1920)is an important commercial cephalopod species in China.This species has declined sharply in recent years.Hence,genetic studies of O.minor are imperative to exploit and manage the wild resource.In this study,46192 microsatellite loci were discovered in 70174 unigenes from the transcriptomic data.Among all of the simple sequence repeat(SSR)unit categories,di-nucleotide and tri-nucleotide SSRs accounted for 45.26%and 14.49%,respectively.A total of 108 SSRs were tested,of which 21 were neutral and polymorphic.Seven SSRs were selected for genetics analyses of the O.minor populations in the Bohai Sea,the Yellow Sea,and the southwest coast of the Taiwan Strait region.Significant pairwise F_(st) values were detected among the samples.The UPGMA tree based on genetic distances suggested that the sampling locations could be arranged in three clusters.These markers are evidence that the populations in this region may be structured,with samples from Penghu differing remarkably from those in northern China.The present study characterized genetic markers for population assessment,management,and conservation of O.minor.

Assessment of Different Traits to Evaluate Genetic Divergence in Some Wheat (<i>Triticum aestivum</i>L.) Genotypes under Late Sowing Condition

The research work was undertaken to identify the extent of genetic diversity in different parameters of wheat related to heat tolerance mechanism. Performances of currently available 25 spring wheat genotypes were studied at the Regional Wheat Research Institute, Shyampur, Rajshahi during the winter season of 2016/2017. All these genotypes (25) were grouped into five clusters on the basis of non-hierarchical clustering parameters viz. cluster I (G2, G5, G6, G16, G20), II (G4, G7, G9, G11, G12, G17), III (G10, G24), IV (G1, G13, G19, G21) and V (G3, G8, G14, G15, G18, G22, G23, G25). These groups were arranged into five (5) pairs of clusters viz. cluster I and III;II and III;II and V;III and IV;IV and V considering their similar potentiality of different traits. Results revealed that the maximum number of genotypes (8) was found in cluster V while cluster III comprised minimum genotypes (2). The inter-cluster distance was higher than intra-cluster distances. The highest and second highest eigenvalues belonged to spike/m2 (25.23%) and spikelets/spike (20.18%) respectively, along with positive canonical values in both the vectors 1 and 2 for these two traits identified them as major traits by exposing their highest potential toward genetic divergence. Cluster III produced the highest spike/m2 (388.8), grain/spike (48.1), plant height (89.5 cm), SPAD (54.2), yield (2799 kg/ha) and biomass (7758.1 Kg/ha) with lowest heading days (64.7 days), maturity days (98.7 days), canopy temperature at vegetative stage (21.7°C) and canopy temperature at grain filling stage (22.4°C). In contrast, cluster V produced the lowest 1000-grain weight (30.4 g) and grain yield (2172 kg/ha) belonging to the highest canopy temperature at both stages (23.8°C and 24.7°C). However, results suggested that the genotypes G10 and G24 under the cluster III, and genotypes G01, G13, G19 and G21 under the cluster IV could be considered as parents for future hybridization program, as well as the five pairs of clusters viz. cluster I and III;II and III;II and V;III and IV;IV and V might be matched as considered for getting more heterotic F1. The results of the study would help to identify the divergent genotypes associate with heat tolerance and this might be helpful in designing future breeding program.

Identification of diverse genotypes with high oil content in Madhuca latifolia for further use in tree improvement

Madhuca latifolia Macb.commonly known as Indian butter tree,is an open-pollinated plant.Improvement in seed and oil yields depends on the progress in the desired characters in the base material and the genetic variability available in the collected germplasm.We evaluated 23 genotypes of M.latifolia to understand genetic variability,character association and divergence in seed traits and oil content for use in breeding programs.Variation was recorded in seed length（27.3–38.6 mm）,seed breadth（15.6–19.1 mm）,two dimensional（2D） surface area（328.3–495.4 mm2）,100 seed weight（216.8–285.3 g）,acid value（13.4–25.8 mg KOH/g）,iodine number（62.4–78.6） and oil content（37.8–51.0 %）.High estimates of genotypic coefficient of variation,broad senseheritability and genetic gain were observed for seed oil content.Variability studies for seed traits revealed that genotype CPT-16 had the highest 100-seed weight（281.5 g） and oil content（51 %）.Highly significant genotypic and phenotypic correlations were observed.The100-seed weight was positively and significantly correlated with oil content at both phenotypic（r = 0.57） and genotypic（r = 0.60） levels.Cluster analysis of the scores of the first three principle components（80.83 %） resulted in four clusters,consisting of 4,7,3 and 9 genotypes in the first,second,third and fourth clusters,respectively.Cluster 3was distinguished from others based on significantly higher means for most seed traits except seed breadth,acid value,iodine number and oil content.Cluster 1 appeared more divergent as it had significantly higher means for acid value and iodine number.A comparative assessment of means of the four clusters for 100-seed weight and oil content suggested that cluster 3 would be useful for higher 100-seed weight and oil content.Hence these genotypes,CPT-3,CPT-6 and CPT-15 in cluster 3 can be used for direct selection and utilization in breeding programs.