Understanding genetic diversity and population structure in forage pea (Pisum sativum var. arvense L.) using inter-primer binding site (iPBS) retrotransposon marker

Forage peas are widely utilized as a source of animal feed, and their fresh shoots, fruits, and pods exhibit considerable potential for human consumption. This study aimed to assess the genetic diversity and population structure of 61 Turkish forage pea genotypes using inter-primer binding site (iPBS) retrotransposon markers. A total of 37 highly polymorphic iPBS primers were employed, producing an average of 69 bands per primer and a cumulative total of 2529 bands. The average polymorphism information content (PIC) was determined to be 0.345. The results revealed significant genetic diversity within the germplasm, as indicated by diversity indices such as the average effective number of alleles (0.704) and a Shannon’s information index (0.299). Molecular analysis of variance (AMOVA) indicated that 74% of the total genetic variation occurred within populations. Population structure analysis identified four distinct subpopulations among the genotypes, with expected heterozygosity values ranging from 0.2404 in the fourth subpopulation to 0.3094 in the second subpopulation, with an overall average of 0.2702. This study represents the first comprehensive investigation of genetic diversity and population structure in forage pea germplasm using the iPBS retrotransposon marker system. The findings highlight the effectiveness of iPBS markers in genetic diversity research and underscore their potential for broader application in the characterization of diverse forage pea collections across different geographic regions.