Genetic diversity and population structure of Greek lentil landraces and cultivars using Inter-Simple Sequence Repeat (ISSR) markers

Abstract

Lentil (Lens culinaris Medik. subsp. culinaris) constitutes one of the most important legumes globally, considering a major food source of protein, carbohydrates, and essential micronutrients. Nowadays, its cultivation is under increasing threat due to adverse climatic conditions. Knowledge of the genetic diversity and structure of the lentil germplasm will lead to a better optimization of its genetic resources in breeding programs in order to adapt to climate change. This study aimed to assess the genetic diversity and population structure of 31 lentil accessions consisting of 22 landraces and 9 commercial cultivars of small-and large-seeded types from Greece using ISSR markers. The ISSR-based characterization of the evaluated lentil populations revealed moderate genetic diversity, with polymorphism ranging from 14.29% to 45.45% and corresponding variation in Nei’s gene diversity (GD = 0.063-0.202) and Shannon’s information index (I = 0.091-0.289). Results from AMOVA indicated that 75% of the total variation fell within populations and so revealed strong intra-population heterogeneity, despite the species being highly self-pollinating. UPGMA and PCoA analyses revealed a central cluster of closely related populations and a set of genetically distinct lineages (DIG, KOR, PEL), while geographic structuring was not detected, suggesting the shaping impact of farmer-mediated seed exchange. Thus, these genetically diverse populations are considered important resources for widening the lentil gene pool for breeding, whereas those presenting low diversity may maintain locally adapted or rare alleles. In conclusion, the obtained results provide an important molecular basis for the conservation and further exploitation of Greek lentil landraces in future breeding programs.