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The diverse microclimatic belts of the Western Himalayan region of India are considered hot spots for genetic diversity of common bean (Phaseolus vulgaris L.). Western Himalayan beans are known for various agronomically superior/important traits including unique aroma, taste and cooking quality. In the present study, 25 unlinked genomic simple sequence repeat (SSR) markers distributed across the common bean genome were used to assess the genetic/allelic diversity among and within populations belonging to the Jammu and Kashmir regions of the Western Himalayas. These two regions are considered most important hot-spots for common bean diversity in western-Himalayas. The analysis of genotypic data of SSR markers revealed a total of 263 alleles with an average of 10.52 alleles per locus. The genetic diversity analysis revealed higher variability in bean landraces belonging to Jammu region (H e = 0.73) as compared to genotypes from Kashmir region (H e = 0.647) and some exotic genotypes (0.71). The genotypes were also phenotyped for four important nutritional traits and the analysis of trait data revealed that sugar content was highest in common bean genotypes from Jammu region, while protein, starch and phenol content were highest in exotic common bean genotypes. Therefore, the superiority of common bean germplasm from Jammu region may be due to a higher level of allelic diversity, more private alleles and higher sugar content. The diverse genotypes based on genotypic data and trait performance will prove useful in future breeding programs aimed at enhancing nutritional contents of common bean varieties. We collected common bean germplasm from two hot-spot regions in the Western Himalayas and evaluated it acrossfour nutritional traits: sugar, starch, protein and phenol contents. We present a comparison of germplasm from these two hot-spots based on trait data and allelic diversity detected by 25 SSR markers. [ABSTRACT FROM AUTHOR]

The north-western Indian Himalayas possesses vast diversity in common bean germplasm due to several years of natural adaptation and farmer's selection. Systematic efforts have been made for the first time for the characterization and use of this huge diversity for the identification of genes/quantitative trait loci (QTLs) for yield and yield-contributing traits in common bean in India. A core set of 96 diverse common bean genotypes was characterized using 91 genome-wide genomic and genic simple sequence repeat (SSR) markers. The study of genetic diversity led to the identification of 691 alleles ranging from 2 to 21 with an average of 7.59 alleles/locus. The gene diversity (expected heterozygosity, He) varied from 0.31 to 0.93 with an average of 0.73. As expected, the genic SSR markers detected less allelic diversity than the random genomic SSR markers. The traditional clustering and Bayesian clustering (structural analysis) analyses led to a clear cut separation of a core set of 96 genotypes into two distinct groups based on their gene pools (Mesoamerican and Andean genotypes). Genome-wide association mapping for pods/plant, seeds/pod, seed weight, and yield/plant led to the identification of 39 significant marker–trait associations (MTAs) including 15 major, 15 stable, and 13 both major and stable MTAs. Out of 39 MTAs detected, 29 were new MTAs reported for the first time, whereas the remaining 10 MTAs were already identified in earlier studies and therefore declared as validation of earlier results. A set of seven markers was such, which were found to be associated with multiple (two to four) different traits. The important MTAs will be used for common bean molecular breeding programs worldwide for enhancing common bean yield. [ABSTRACT FROM AUTHOR]