Abstract

Genetic variability is of prime importance for the improvement of many crop species including Brassica. Genetic diversity was evaluated in fifteen lines of Brassica Juncea using randomly amplified polymorphic DNA (RAPD) as molecular marker. Four RAPD primers were used to estimate the genetic distances among the genotypes in all the possible combinations. The study of genetic diversity revealed different levels of polymorphism for RAPD primers GLA 02, GLA 03, GLC 08 and GLD 18 that resulted in amplification of 2.06, 2.6, 1.85 and 2.53 scorable bands (loci) per genotype of B. juncea. A high degree of genetic polymorphism at DNA level was observed among the Brassica lines with average genetic distance ranging from 14.45 to 25.43%. The dissimilarity coefficient matrix of these lines based on the data of four RAPD makers using un-weighted pair group of arithematic means (UPGMA) method was also used to construct a dendrogram. The dendrogram analysis indicated that the lines PR57/72, KS-74, RL-18 and Fsd-87005-1 were genetically apart from other lines that can be exploited to create wider genetic base in Brassica germplasm.

Key words: Rapeseed, mustard, Brassica juncea, genetic variability, molecular markers, randomly amplified polymorphic DNA (RAPD).

Abbreviation

Abbreviations: PCR, Polymerase chain reaction; SDS, sodium dodecyl sulfate;EDTA, ethylene diamine tetra acetic acid.