Molecular mapping and identification of quantitative trait loci for yield components in rapeseed (Brasscia napus L.)

Abstract

A F2 segregating population for genetic map construction and identification of QTL for seed yield in rapeseed (Brassica napus L.), was developed via crossing a conventional rapeseed line 04-1139 with a high yielding multiple silique rapeseed line 05-1054. A genetic map including 19 linkage groups was constructed with 200 SSR (Simple sequence repeat) and SRAP (Sequence-related amplified polymorphism) markers. This map covers a total length of 1 700.23 cM with an average distance between two adjacent makers of 8.50 cM. Using this map, QTL for the components of yield per plant, such as number of silique per plant (SNP), number of seeds per silique (SS) were analyzed. A total of 12 putative QTL for the traits were detected. Four of them were associated with SNP, which explained 35.64%, 12.96%, 28.71%, and 34.02% of the variation, respectively. Five QTL, which explained 8.41%, 7.87%, 24.37%, 8.57%, and 14.31% of the variation, were responsible for SS. Three QTL for 1 000-seed weight explained 1.81%-2.33% of the variation. The additional effects of the alleles for a trait may originate from both parents. The markers associated with the main QTL can be a good tool for marker associated selection and pyramiding breeding.