甘蓝型油菜早熟性状QTL定位及候选基因筛选

目前对于油菜早熟的研究主要围绕开花期性状进行,虽然开花期与生育期呈显著正相关,但却并不完全一致。对于油菜开花后一系列生长发育进程相关性状的遗传研究和QTL定位鲜有报道。本研究以成熟期差异较大的2个油菜品种‘花前早’和‘Global’构建的DH群体为材料,对影响油菜全生育期的各个发育阶段(开花期、花期持续时间、角果期持续时间和全生育期等)进行表型调查和QTL定位分析。共检测到30个早熟相关性状QTL位点,其中开花期、花期持续时间、角果期持续时间和全生育期等分别检测到12、5、4和9个QTL位点,解释了5.8%~22.4%的表型方差。发现4、2和1个全生育期QTL置信区间分别与开花期、花期持续时间、角果期持续时间位点置信区间完全或部分重叠。筛选到29个可能与油菜早熟性状相关的候选基因,它们通过调控花期或籽粒发育等生长发育进程影响油菜早熟。因此,在早熟性状的研究中,可以同时从开花期和籽粒发育过程入手,不但有利于使熟期进一步提前,也可减缓早熟油菜品种过早开花导致的冬前低温寒潮天气的不利影响。

QTL mapping and candidate genes screening of earliness traits in Brassica napus L.

Currently,the research on earliness traits of rapeseed mainly focused on flowering time.Although there was a significant positive correlation between the flowering period and the growth period,it was not completely consistent.There are few reports on the genetic studies and QTL mapping of traits related to rapeseed growth and development after flowering.We carried out phenotypic survey(flowering time,flowering period duration,silique period duration etc.)and QTL mapping with the DH population constructed by‘Huaqianzao’and‘Global’as material.A total of 30 QTL loci for earliness traits were detected.Among them,12,5,4 and 9 QTL loci were detected in the flowering time,flowering period duration,silique period duration and full growth period,respectively,explaining 5.8%–22.4%phenotypic variance.The 2,4,and 1 QTL confidence intervals of full growth period were found overlap in part or in whole with flowering time,flowering period duration and silique period duration respectively.The 29 candidate genes were screened,which affected the earliness traits by regulating flowering or silique development in rapeseed growth and development processes.Therefore,in the study of earliness traits,we could consider flowering time and silique development process at the same time,which not only helps to advance the maturity period,but also reduces the adverse effects of early flowering.