Ecology, Environment and Conservation Paper

GENETIC DIVERGENCE FOR IRON AND ZINC IN PIGEONPEA GENOTYPES USING MOLECULAR MARKERS

Sweta Mishra and Suresh Acharya2

Abstract

The molecular characterization of the pigeonpea genotypes using RAPD markers revealed 79.75 per cent polymorphism. Nineteen RAPD markers produced informative bands varying from 473 to 2546 bp for seed iron and seed zinc concentrations in different genotypes. The markers OPH 5, OPH 10, OPH 17 and OPP 2 were able to discriminate 82.7 per cent of the genotypes. OPX 13 exclusively amplified 784 bp in high seed iron containing genotypes, while OPI 18 specifically amplified a 900 bp band in low seed zinc containing genotypes. Pairwise genetic similarity indices varied from 0.38 to 0.91 among different genotypes indicating a wide range of genetic diversity in the pigeonpea genotypes at molecular level. The UPGMA clustering grouped the pigeonpea genotypes into two clusters entailing 79 and 24 genotypes, respectively. Cluster II had high values for seed iron and seed zinc concentrations than cluster I. The cultivated Indian C. cajan exhibited lower level of molecular variability than the wild types. All the genotypes of C. scarabaeoides were grouped together and all the genotypes from the quaternary gene pool (1C. platycarpus, R. rothii, R. cana, R. rufescens and R. suaveolens) were grouped into another cluster. C. cajanifolius was found to be closely related to Indian C. cajan while C. scarabaeoides may have contributed to the evolution of the cultivated African species. The clustering of the Indo-African genotypes separate from the Indian and African C. cajan accessions suggests that these genotypes represent distinct germplasm and could be used to construct highly polymorphic populations.