甘蓝型油菜角果性状QTL定位

Silique is the most important photosynthetic organ in the later period of rapeseed growth. Silique length (SL), number of seeds per silique (SN) and thousand seed weight (TSW) are known as direct or indirect factors influencing seed yield in Brassica napus. One hundred and eighty-one double haploid (DH) lines derived from two lines with distinct silique traits were employed to map quantitative trait loci (QTL) for SL, SN and TSW in B. napus. Field data from three environments were collected for correlation analysis and QTL mapping for SL, SN and TSW. The broad-sense heritability of SL, SN and TSW was 95.24%, 67.24% and 91.01%, respectively, suggesting that genetic variance played a leading role in total variations for SL and TSW. 37 consensus QTL and 31 unique QTL were identified by two-round meta-analysis. Among the 37 consensus QTL, two, two, four QTL detected on A9, A9 and A1 linkage group had effects on SL, TSW and SN. It could explain more than16.22-64.36% of trait variation. In addition, two, two, and three pairs of additive by additive (AA) interactions with small effects were detected for SL, SN and TSW, respectively. Our results will provide a basis for map-based cloning of QTL affecting silique traits and marker-assistant selection (MAS) in breeding of new rapeseed variety exhibiting higher seed yield.