Abstract:

Apetalous rapeseed has the advantages of high solar radition utilization efficiency, low sclerotinia incidence ratio, strong root assimilation efficiency, and high yield potential owing to the loss of petal. Apetalousness is controlled by two to four recessive genes in rapeseed. All researchers consider the plants with less than 10% petalous degree (PD) as the apetalous, but the distribution of PD in segregation generation is consecutive. The apetalous should be treated as a quantitative trait to screen QTLs. In present research,an apetalous rapeseed line APL01 was crossed with a normal petalous line M083 to develop a segregating population BC₁F₁. This population was used to construct a genetic map and identify QTLs affecting the apetalous in rapeseed (Brassica napus L.). Totally, 219 SRAP, 25 SSR, and 7 RAPD markers were used to construct a genetic map containing 19 linkage groups in rapeseed. This map was aligned with the ultradense genetic recombination map for B. napus L., and four QTLs were identified by WinQtlCart. QAP5 was located in the region of A0226Bb152–m31e40b on linkage group (LG) N5, which could explain 3.71% of the petalous variation in segregation population BC₁F₁. QAP6 was mapped in the region of m25e7–OPY9 on LG N6, and accounted for 3.02% of phenotypic variation. QAP8 was located between A0226Gb468–m29e20 on LG N8 and explained 30.94% of phenotypic variation. QAP15 was located in the region of m21e4b–A0225Bb201 on LG N15, and accounted for 21.96% of phenotypic variation. Two main-effect QTLs of them (QAP8 and QAP15) could be applied in marker-assisted selection for apetalous rapeseed breeding, and the other two QTLs (QAP5 and QAP6) were modified genes.

Key words: Rapeseed, Genetic map, Apetalous, QTLs