Morphological and molecular characterization of Brassica rapa ssp. yellow sarson mutants.

Abstract

Thirteen out of 55 gamma-rays induced promising mutants of Brassica rapa ssp yellow sarson along with their two parents namely, NDYS-2 (V1) and YST- 151 (V2) were investigated with a view to characterize the genetic variability through morphological as well as ISSR markers analysis. Mutants showed wide range of variability for seed yield, yield attributes, oil content (%) and Alternaria blight disease reaction. Five mutants, namely, V1M5, V1M20, V1M42, V1M43 and V1M54 showed significantly high seed yield and high oil content as well as improved level of tolerance to Alternaria blight as compared to parents. Investigation using ISSR analysis showed high degree of variation yielding 78 bands scored for the presence or absence of bands among genotypes. Three out of 13 oligonucleotide primers gave reproducible DNA bands suitable for establishment of genetic diversity. Genetic similarity ranging from 0.54 to 0.91 using UPGMA cluster analysis based on ISSR bands was noticed. The mutants were put into three major clusters; cluster II was represented by three sub-clusters IIAa, IIAb and IIB. The present investigation clearly indicated that morphological traits alone could not be considered as the true reflection of their genotypic characteristics and hence the need of molecular analysis using ISSR markers is proved.