海岛棉高密度连锁遗传图谱构建及抗病标记辅助选择效应评价

Sea island cotton(G. Barbadense) possesses superior fiber quality. It was attributed that are unavailable in G. hirsutum for textile mills.There are unique area for plant sea iland cotton in Xinjiang in China. Recently,the product of sea island cotton was effected severity by Fusarium wilt. Nowaday nearly 80% sea island cotton production area was threated by Fusarium wilt, and 15% was very severitly, even no production. Because it is seldom reported about the machanism of sea island cotton resistance Fusarium wilt, and there are no significant promotion the trait of disease resistance by breeding program. So, we employed the high disease resistance cultivar and susceptivity cultivar to construct a mapping population, then we get the primary genetic map. In the basis, we will use next generation sequencing to analy the gene expression profiles in infection with Fusariun wilt, and selecte different expression EST sequence and SNP which will be used to construct high density genetic map of G.Barbadense. The RIL will be plant in field and greenhouse to survey the trait of disease resistance. Then we will locate the disease resistance QTLs, and selecte the markers linkage with disease resistance, use these markers to do marker assisted selection. Through evaluated the effection of MAS compare with common breeding, raise the proposal about molecular breeding of G.Barbadense disease resistance. This research will have important theory and practise purport to reveal the mechanism of disease resistance in G. babadense, put in practice of marker assisted selection breeding, and clone gene of disease resistace. Also it has important implications for research the origin and domestication of cotton using the high-density genetic map of G. Barbadense.

海岛棉以其优异的纤维品质成为纺高支纱和特种纱不可替代的原料。新疆是我国海岛棉的唯一产区。近年来由于枯萎病危害，海岛棉生产受到严重挑战，目前80%以上产区发生枯萎病危害，其中15%以上为重病田，造成绝产绝收。由于海岛棉抗枯萎病机理研究较少，通过常规育种培育抗病品种收效甚微。本项目利用抗病、感病差异明显的亲本材料配置组合，初步构建遗传连锁图谱，在此基础上利用第二代测序技术开展抗病表达谱分析，筛选差异表达的EST序列和SNP，进一步加密遗传连锁图谱；用已获得的RIL考察抗病性，定位抗病QTLs，筛选与抗病性紧密连锁的分子标记并实施标记辅助选择；通过与常规选择相比较，评价标记的选择效应，提出海岛棉抗枯萎病的标记辅助选择育种方案。本项目的实施将为揭示海岛棉抗病分子机理、实施分子标记辅助选择育种、克隆抗病基因提供理论和应用基础；同时海岛棉高密度遗传连锁图谱的构建对研究棉花的起源进化也具有理论意义。

近年来由于枯萎病危害，新疆海岛棉生产受到严重挑战，目前80%以上产区发生枯萎病危害，其中15%以上为重病田，造成绝产绝收。由于海岛棉抗枯萎病机理研究较少，通过常规育种培育抗病品种收效甚微。本项目利用抗病、感病差异明显的亲本材料配置组合，通过转录组测序、连锁遗传图谱加密、抗病QTL定位以及对所获得的标记的评价，探讨海岛棉抗枯萎病的遗传机制。通过项目研究得到以下结论 .1）构建了15个连锁群、包含240个多态性标记，全长3962.56cM的连锁遗传图谱。构建的整合遗传连图谱基因组覆盖率约79.25%，标记间平均距离16.65cM。.2）共检测到12个QTLs，分别位于Chr1、Chr3、Chr8、Chr12、Chr16、Chr26。在3环境下均能检测到的QTL为qFw8-1、qFw3-1、qFw26-1、qFw1-1，集中在8、3、26、1号染色体上，该染色体为控制病级数量性状的热点区段，为极稳定的QTL，控制枯萎病的基因很可能存在于该数量性状基因座位内。.3）利用定位于1号、8号、16号染色体上与抗枯萎病有关连锁的6对标记进行标记与病级和农艺性状之间的相关分析，可得到定位标记014、016、BNL1421和棉花枯萎病病级显著相关，3对可作为有效的遗传标记用于海岛棉抗枯萎病的相关分析，标记DPL0030与 016与衣分表现显著，标记014与单铃重、衣指、子指的表现显著。.4）差异表达基因分析表明在感染枯萎病菌样本中植物抗病响应蛋白基因（PR1、PR3）、毒素分解代谢过程相关基因（GSTF、GSTU）、防御机制相关基因（MRP）、NPR基因、棉酚生物合成相关基因（ACLA）及抗病性R基因（ZAR1、RPS2）等已知抗病相关基因都显著高表达。差异表达基因功能聚类结果表明，感染枯萎病菌与未感染枯萎病菌样本相比，在感染枯萎病菌样本中都富集到了糖基转移酶、类黄酮生物合成相关基因富集性高表达。这些代谢路径中的基因成员与海岛棉抗病性相关，可作为研究海岛棉抗病性的候选基因。.5）获得专利一项：植物表达载体及其应用，ZL201310354203.6，申请日期2013.8.14，授权日期2015.9.30。.6)发表论文7篇.7）培养研究生4名