RAPD and ISSR derived SCAR marker(s) for Aphid tolerance in Brassica juncea Czern. And Coss

Abstract

In this present study, eight genotypes of Brassica juncea comprising four tolerant (IC-399802, IC-491089, IC-312545, IC-312553) and four susceptible (IC-385686, IC-264131, IC-426392, Laxmi) genotypes for aphid tolerance were used to generate Sequence Characterized Amplified Region (SCAR) markers through dominant PCR based markers (51 RAPD and 12 ISSR markers). 13 RAPD (Random Amplified Polymorphic DNA) and 8 ISSR (Inter Simple Sequence Repeat) markers were found to be polymorphic but only 3 primers OPE16 (RAPD), UBC 839 (ISSR) and UBC 864 (ISSR) were obtained which could distinguish tolerant genotypes from susceptible ones. OPE16 (RAPD) obtained unique band of size approx. 600 bp in susceptible genotypes while it was absent in the tolerant genotypes. Similarly, UBC 839 (ISSR) yielded ~800 bp unique band in bulk tolerant while UBC 864 (ISSR) yielded three bands of ~1200 bp, ~1000 bp, and ~500 bp in tolerant genotypes which was absent in the susceptible genotypes. These unique bands were excised to generate five sets of SCAR markers. Among the five sets of SCAR marker, only BJSCAR F1 and BJSCAR R1 set yielded the promising result in all for 4 susceptible genotypes as well as bulk susceptible and was absent in all the tolerant genotypes and Brassica fruticulosa (highly tolerant to aphid, used as a control). So, this SCAR marker developed could be successfully used in screening of B.juncea genotypes in future breeding programs.