Genetic Diversity and Population Structure of Germplasm Resources in Sesame (<I>Sesamum indicum</I> L.) by SSR Markers

Abstract Genetic diversity and structure analysis using molecular markers is necessary for efficient utilization and sustainable management of gladiolus germplasm. Genetic analysis of gladiolus germplasm using SSR markers is largely missing due to scarce genomic information. In the present investigation, we report 66.66% cross transferability of Gladiolus palustris SSRs whereas 48% of Iris EST-SSRs were cross transferable across the gladiolus genotypes used in the study. A total of 17 highly polymorphic SSRs revealed a total 58 polymorphic loci ranging from two to six in each locus with an average of 3.41 alleles per marker. PIC values ranged from 0.11 to 0.71 with an average value of 0.48. Four SSRs were selectively neutral based on Ewens-Watterson test. Analysis of genetic structure of 84 gladiolus genotypes divided whole germplasm into two subpopulations. 35 genotypes were assigned to subpopulation 1 whereas 37 to subpopulation 2 and rest of the genotypes recorded as admixture. Analysis of molecular variance indicated maximum variance (53.59%) among individuals within subpopulations whereas 36.55% of variation observed among individuals within total population. Least variation (9.86%) was noticed between two subpopulations. Moderate (FST = 0.10) genetic differentiation of two subpopulations was observed. Grouping pattern of population structure was consistent with UPGMA dendrogram based on simple matching dissimilarity coefficient (ranged from 01.6 to 0.89) and PCoA. Genetic relationships assessed among the genotypes of respective clusters assist the breeders in selecting desirable parents for crossing. SSR markers from present study can be utilized for cultivar identification, conservation and sustainable utilization of gladiolus genotypes for crop improvement.

Download Full-text

Genetic diversity and population structure of Hemibagrus guttatus (Bagridae, Siluriformes) in the larger subtropical Pearl River based on COI and Cyt b genes analysis

Annales de Limnologie - International Journal of Limnology ◽

10.1051/limn/2021005 ◽

2021 ◽

Vol 57 ◽

pp. 7

Author(s):

Tianxu Kuang ◽

Fangmin Shuai ◽

Xinhui Li ◽

Weitao Chen ◽

Sovan Lek

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Sustainable Use ◽

Haplotype Diversity ◽

Pearl River ◽

Germplasm Resources ◽

Geographical Populations ◽

Commercially Important ◽

The Pearl River ◽

F Statistics

Understanding the genetic diversity and population structure of fish species is crucial for the sustainable use and protection of fish germplasm resources. Hemibagrus guttatus (Bagridae, Siluriformes) is widely distributed in the large subtropical Pearl River (China) and is commercially important. It's population have been declining. The genetic diversity of wild H. guttatus is not clear, despite its important ecological significance. In this paper, genes mitochondrial cytochrome c oxidase subunit I (COI) and cytochrome b (Cyt b) were used to analyze the genetic structure of H. guttatus population collected from six geographical populations in the main streams of the Pearl River. The results showed that the nucleotide diversity (π) and haplotype diversity (Hd) of wild H. guttatus was low (π < 0.005; Hd < 0.5). In addition, H. guttatus haplotypes did not cluster into clades according to geographical distribution, as revealed by neighbor-joining tree analysis. Analysis of molecular variance analysis (AMOVA) and F-statistics (Fst) values showed high homogeneity among wild H. guttatus populations. Our results suggest that there is degradation in germplasm resources of H. guttatus that could destabilize the sustainable use of this species and there was an urgent need for conservation of this species in South China.

Download Full-text