Investigation of IRAP transposon-based molecular markers for analysis of genetic diversity in pea germplasm

Retrotransposons diversity has been extensively studied in monocots, but it is not well documented in dicot species. Transposition activity of transposons creates DNA polymorphism and their abundant presence in genomes is making transposons a promising marker system for varietal identification and fingerprinting. In this study, four transposon-based markers (two DNA- and two RNA-transposons) were employed to evaluate the effectiveness of Inter-Retrotransposon Amplified Polymorphism (IRAP) transposon system in assessing genetic diversity in pea germplasm accessions. A total of 28 alleles were detected across the 35 pea accessions with number of alleles per locus ranged from 5 (Mutator) to 9 (Cyclops). RNA transposons produced a higher number of polymorphic alleles (Ogre: 8, Cyclops: 9) than DNA transposon markers (Mutator: 5, MITE: 6). Overall mean PIC value and D values for these transposon markers were 0.810 and 0.817 respectively. Genetic similarity values ranged from 0.143 to 0.823 with a mean similarity value of 0.403. Cluster analysis classified pea genotypes into six major groups that were somewhat consistent with their geographical origins. The molecular analyses differentiated all the 35 accessions and generated higher PIC and D values that can be useful for MAS-based breeding programs in pea.