Genetic Diversity Analysis in White Yam (Dioscorea rotundata Poir.) using Random Amplified Polymorphic DNA (RAPD) Markers

Abstract

White yam (Dioscorea rotundata Poir) is grown as a major food crop in tropical countries. It is emerging as an important tuber crop in India especially in Kerala and it is well known for its yield potential. ICARCentral Tuber Crops Research Institute holds a field gene bank of 1100 Dioscorea accessions including 158 white yam genotypes. Genetic variability in plants can be used for developing improved cultivars with desirable traits. Present study focused on identifying genetic variability in 30 white yam genotypes (Dwarf, Semi dwarf and Tall) using 19 random oligonucleotide primers for RAPD analysis. On 19 RAPD primers, only 8 primers were selected based on their polymorphism and repeatability. Among the eight RAPD primers studied in white yam, OPW -16 was found be the best that produced ten polymorphic bands. All the primers evaluated resulted in 100% polymorphism. All the primers were recorded with high PIC value of >0.6. Dendrogram based on RAPD marker showed nine clusters at 0.8 dissimilarity level. It also shows the high divergence of the genotype V20 (DR17) and the clustering pattern indicates the grouping of the dwarf genotypes together. More or less similar clusters were obtained based on certain morphological characteristics of the genotypes observed in the field study.