Genomic Insights into Cold-Tolerant Pea Genotypes: A Molecular Diversity Study Using ISSR Markers

Abstract

Pea (Pisum sativum L.) is a valuable legume species used in human and animal nutrition due to its rich protein, carbohydrate, vitamin, and mineral content. However, its adaptation to dry and warm climates is limited, necessitating early spring sowing to ensure successful growth and yield. Therefore, the development of cold-tolerant cultivars has become a key objective in pea breeding programs, particularly to enhance adaptability and stability in temperate regions. Molecular marker-based analyses provide a complementary approach to traditional selection methods, offering insights into genetic diversity and parental relationships that are critical for effective hybridization strategies. In the present study, genetic relationships among 32 pea genotypes, including advanced lines, hybrids, and registered varieties, were assessed using 19 Inter Simple Sequence Repeat (ISSR) markers. A total of 88 scorable bands were obtained, with polymorphism levels ranging from 20% to 100%. The mean polymorphism rate across markers was 67%, while the average resolving power ranged from 0.09 to 0.88. Genetic similarity coefficients among genotypes ranged from 0.60 to 0.93. Most hybrids were found to cluster more closely with their cold-tolerant parental lines, suggesting successful introgression of desired traits. The clustering analysis further confirmed the presence of sufficient genetic variability to support ongoing selection and recombination within the breeding program. Overall, the findings highlight the utility of ISSR markers as a reliable tool for assessing genetic diversity and informing the selection of elite lines in pea breeding. The integration of molecular data with morphological and phenological evaluations can significantly accelerate the development of high-yielding, cold-tolerant pea cultivars adapted to early spring sowing conditions.