野生甘蓝表皮毛基因的精细定位

Resistance breeding against pathogens and insects is one of the most important targets of Brassica oleracea breeding, however, the resistance breeding progress has been greatly hampered due to the lack of resistant source in current B. oleracea germplasm. Wild germplasm is with great value in improving cultivated crops since wild forms always possess elite resistance genes against pathogens, insects and hard enviromental factors. Among the wild forms of B. oleracea, B. incana, with the whole plant covered by dense trichomes, was proved to be with excellent resistance against verious pathogens and insects. It was revealed from our previous studies that the trichome of B. incana is controled by a ressessive gene which locate in a 7.2-cM region on linkage group C01 of B. oleracea. The present study is targeted to fine map this gene in a 0.5-Mb area via genomic resequencing of bulked samples with/without trichomes. This study is with direct values on digging and providing elite gene resources to cultivated crops of B. oleracea, and it is also of great importance on utilizing wild germplasm in improving resistance of B. oleracea crops against diseases and insects.

抗病虫育种是甘蓝类蔬菜的主要育种目标之一，但我国甘蓝种质资源特别缺乏可用的抗病、抗虫优异种质，限制了甘蓝的抗病和抗虫育种进程。野生甘蓝具有较好的抗逆性，尤其有一种野生类型（Brassica incana）表现出极为突出的抗病虫能力。该野生甘蓝周身具有显著的表皮毛特征，并且我们前期研究发现，B. incana的表皮毛主要受隐性单基因的控制，该基因位于甘蓝C01连锁群上7.2 cM范围内。本项目申请拟将传统的精细定位与基于BSA法的全基因组重测序结合，对野生甘蓝B. incana的表皮毛基因进行精细定位，将目标基因锁定在0.5 Mb范围以内。本项目的开展对于挖掘甘蓝的表皮毛基因、为甘蓝类作物的抗病和抗虫育种提供重要的基因资源有直接意义，同时对于挖掘野生甘蓝种质资源潜力、利用野生甘蓝改良栽培甘蓝的抗逆性有潜在的实际意义。

植物表皮毛具有保护植物免受昆虫和病原体的侵害，并降低机械损伤和紫外光等伤害，减轻冷冻损伤的功能，对生物和非生物胁迫具有防御作用。本项目计划采用BSA方案，通过基因组重测序手段锁定B. incana表皮毛基因所在的区域，并在大的F2群体中精细定位B. incana的表皮毛基因。项目执行期，我们对技术手段做了调整，将重测序改为SNP芯片分析，根据原计划技术路线，将甘蓝表皮毛候选区间锁定在甘蓝的C01染色体上一段1 Mb区域内，并我们通过实验从该区间预测到一个候选基因BoTRY，发展了与其紧密连锁的分子标记。本项目的顺利开展对于挖掘甘蓝的表皮毛基因、为甘蓝类作物的抗病和抗虫育种提供重要的基因资源有直接意义，同时对于挖掘野生甘蓝种质资源潜力、利用野生甘蓝改良栽培甘蓝的抗逆性有潜在的实际意义。