Genetic Characterization and Population Structure of Pea (Pisum sativum L.) by Molecular Markers against Rust (Uromyces viciae-fabae) in Newly Developed Genotypes

The understanding of the genetic diversity of germplasm of any crop is necessary for genetic improvement. Pea (Pisum sativum L.) is a very important legume crop that provides protein and several essential vitamins, carbohydrates, and minerals. The genetic diversity and population structure of pea germplasm consisted of 115 entries of Australian accessions and 4 entries of Indian varieties used as checks with varying responses and severities of rust, which were analysed using 31 polymorphic SSR (Simple Sequence Repeats) markers. The combination of the markers revealed that 78 alleles were present at 32 loci. It was also observed that each marker had three alleles with an average PIC (Polymorphic Information Content) value of 0.272. The population structure analysis showed the genetic differentiation of the entries. The model-based population structure grouped the entries into three sub-populations of SP1, SP2, and SP3 having 37, 35, and 32 entries, respectively with 15 entries as admixtures. AMOVA (Analysis of Molecular Variance) disclosed that there was 56% variation among the individuals and 20% within the population. A mean fixation index (Fst) of 0.240 among the pea entries exhibited relatively significant variation in population. This study provides basic information to select parental lines for developing rust resistant varieties to meet the ultimate goal of sustainable agriculture.

Automated summary

Understanding the genetic diversity and population structure of pea germplasm is necessary for developing rust resistant varieties. This study analyzed 115 Australian accessions and 4 Indian varieties using 31 polymorphic SSR markers, revealing 78 alleles and three alleles per marker on average. The population structure analysis identified three sub-populations and showed significant variation among the pea entries.