Development of an AFLP-based linkage map and localization of QTLs for seed fatty acid content in condiment mustard (Brassica juncea)

Abstract

A genetic linkage map of Brassica juncea based on AFLP and RAPD markers was constructed using 131 F1-derived doubled-haploid (DH) plants from a cross between two mustard lines. The map included 273 markers (264 AFLP, 9 RAPD) arranged on 18 linkage groups, and covered a total genetic distance of 1641 cM; 18.3% of the AFLP markers showed a segregation distortion (P < 0.01). The markers with biased segregation were clustered on seven linkage groups. QTLs for oil contents, palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2), linolenic acid (18:3), eicosenoic acid (20:1), and erucic acid (22:1), were mapped on the AFLP linkage map. Correlation studies among fatty acids in the DH population and the localization of QTLs involved in their control indicated that a major gene located on linkage group (LG) 2 controlled the elongation step of erucic acid.Key words: Brassica juncea, doubled haploid, AFLP genetic linkage map, fatty acids, QTL.