甘蓝型油菜MAGIC群体构建及其在遗传育种中的应用潜力

摘要

Multi-parent advanced generation inter-cross (MAGIC) population became a new tool for genetic mapping and breeding in crops.To explore the potential application of MAGIC lines on rapeseed breeding,a population encompassing 680 lines was developed by crossing 8 elite parents.All lines advanced by single seed descent method.At F3 generation,several phenotypes including disease resistance,yield potential and plant architecture were investigated,and 204 of 680 lines were chosen to form a sub-population for further selection.At F6 generation,several main agronomic traits of 204 lines and 8 parents were collected.The traits included plant height,number of primary branch,effective length of main raceme,effective siliques of main raceme,silique length,seeds per silique,thousand seeds weight and plant yield.Results showed that variation of main agronomic traits in this population had normal distribution.Differences of 5 traits were significant comparing to their parental population.The 5 traits included number of primary branch,effective length of main raceme,silique length,seeds per silique and thousand seeds weight.It indicated that MAGIC population was the ideal substitute for elite lines selection by traditional method in rapeseed breeding.Seed yield and ecological adaptability were tested in 3 sites (Jingzhou,Gong'an,Yuxi) for 2 years.9 elite lines were obtained with better resistance to Sclerotinia sclerotiorum,high yield and high quality performance.%多亲本高级世代互交(multi-parent advanced generation inter-cross,MAGIC)群体是一类新型的遗传作图和育种群体.为探讨MAGIC群体在油菜遗传育种中的应用潜力,采用8亲本互交技术构建了一个含680个株系的甘蓝型油菜MAGIC群体,并应用单粒传法对群体材料进行连续套袋自交繁殖.在F3,根据抗病表现、增产潜力及株型从中优选了204个株系构建了选种基础群体;在F6,对各株系及其亲本的株高、一次分枝数、主花序有效长度、主花序有效角果数、角果长度、每角粒数、千粒重和单株产量等主要农艺性状进行了观测和比较.结果表明,群体中的主要农艺性状变异均符合正态分布,且一次分枝数、主花序有效长度、角果长度、每角粒数和千粒重5个性状相对亲本群体达到了显著或极显著差异,是一个优良品系选育的理想群体.通过2年3试点的测产试验和生态适应性观测,共从该群体中选出了9个菌核病抗性较好、增产优势明显的优良株系,为组建甘蓝型油菜多基因型种群品种提供了组份材料.