【作者】 吕红豪；

【导师】 方智远； 王晓武； 杨丽梅；

【作者基本信息】 中国农业科学院 ， 蔬菜学， 2014， 博士

【摘要】 结球甘蓝（Brassicaoleraceavar.capitataL.）是一种重要的十字花科芸薹属蔬菜作物。自2001年以来，在我国甘蓝产区出现了由尖孢镰刀菌引起的甘蓝枯萎病，严重影响了甘蓝的产量和品质。甘蓝枯萎病最早发现于美国，后来在很多国家迅速蔓延。在我国，甘蓝枯萎病属于新发病害，相关研究尚处于起步阶段。目前，导致国内甘蓝枯萎病的致病菌小种类型尚未全面确定；国内现有的育种材料抗性尚不够明确，抗枯萎病的甘蓝品种培育刚刚起步；甘蓝枯萎病分子标记方面研究很少，抗枯萎病基因的研究尚未见报道。本研究针对病情和病原调查、基因的定位和克隆、抗病品种选育方面开展了一系列工作，结果如下：1.甘蓝枯萎病危害情况及病原调查：调查了近几年甘蓝枯萎病在中国的危害情况，十几年间甘蓝枯萎病从北京（2001年）发展到5个省市（北京、河北、山西、陕西、甘肃）（2013年），危害面积不断增加。在上述5个省市采集病株并分离纯化致病菌，通过多种方法将这些致病原菌菌株鉴定为尖孢镰刀菌菌粘团专化型（Fusarium oxysporum f. sp. conglutinans）1号小种，但致病力更强。2.甘蓝抗枯萎病基因的定位和克隆：利用双亲重测序数据开发了InDel分子标记，利用DH群体完成了抗性基因的初步定位工作，将抗性基因定位在C06染色体上384kb范围内。在DH群体初步定位的基础上，利用来源于相同亲本的F2群体对抗性基因进行了精细定位，最终将抗性基因定位在84kb的区域内。通过多种途径分析和获得了候选基因，结果显示，候选基因FOC1属于TIR-NBS-LRR类型的抗病基因。利用80份自交系材料对候选基因进行了分析和验证。3.甘蓝枯萎病抗源筛选和抗病品种选育：筛选获得了新的高抗育种材料8份，新的组合11个；利用游离小孢子培养获得了一个包含196个系的DH群体；结合农艺性状调查和分子标记筛选，获得了抗病且表现优良的DH系。将3个优良DH系与优良自交系配制杂交组合，3个表现抗病且优良。综上所述，本研究取得的结果具有以下两方面意义：首先，在应用层面：本研究对甘蓝枯萎病在国内的危害情况进行了调查，明确了病害发生的规律，总结了防控措施；鉴定了病原类型；对现有的育种材料进行了鉴定筛选；利用小孢子培养和标记辅助选择创制了新的育种材料并配制了新的优良抗病组合。该研究为甘蓝的抗枯萎病育种提供了依据，为甘蓝枯萎病的防控提供了参考。其次，在基础研究层面：本研究对甘蓝抗枯萎病基因进行了定位，通过分析获得了候选基因并利用多份材料进行了验证。该结果为进一步分析基因功能奠定了基础，也为分子辅助育种、加速育种进程提供了依据。更多还原

【Abstract】 White cabbage (Brassica oleracea var. capitata) is an important brassica crop. Since2001, cabbageFusarium wilt (CFW) caused by Fusarium oxysporum hit the cabbage growing area in northern China,causing great losses to both yield and quality of cabbages in China.CFW was firstly found in the US and then hit many other countries where cabbages were grown. InChina, CFW was newly discovered and related research has just begun. Currently, the race type of theCFW pathogen in China has never been discovered; the resistance level of the breeding materials has notbeen identified yet and the CFW resistance breeding work is just at a starting stage; molecular markerresearch about CFW resistance is rare, and studies concerning mapping and cloning of the resistance genehave not been reported yet. The study here reported evaluation of the damage situation, identification ofthe pathogen type, mapping and cloning of the resistant gene and cultivation of CFW resistant varieties.The results are as follows:1. Damaged situation evaluation and pathogen type identificationThe damaged situation by CFW in China was evaluated. In a decade, CFW has developed fromBeijing in2001to four other provinces including Hebei, Shanxi, Shaanxi and Gansu in2013. Both thedamaged area and the losses of cabbage production were increased continuously. We further isolatedpathogens from the five provinces. All the isolates were identified to be Fusarium oxysporum f. sp.conglutinans Race1, however, these strains were found to be more virulent.2. Mapping and cloning of the CFW resistance geneInDel markers were developed using the re-sequencing data of the parents from which the DHpopulation was derived. The resistance gene was mapped to a384kb region on chromosome C06usingthe DH population. The F2population derived from the same parents was used to further fine mapping ofthe gene to an84kb region. The candidate gene for resistance to CFW in cabbage was obtained andconfirmed through several ways. The result showed that the candidate gene FOC1belonged to the TIR-NBS-LRR type R gene. The candidate gene was further confirmed by analysis of variation locus of FOC1in80cabbage inbred lines.3. Screening of the resistant materials and cultivation of CFW resistant varietiesEight new inbred lines and11hybrids were identified with high resistance to CFW. Microsporeculture was conducted to obtain a total of196DH lines. Three elite DH lines were selected based on theagronomic traits evaluation and molecular marker assays. Hybrids derived from the three DH lines andother inbred lines were obtained through hand pollination and three of them were identified with bothelite agronomic traits and high resistance to CFW.In summary, the study reported here is of great significance in two aspects:Firstly, in the aspect of application, we evaluated the damage situation of CFW in China, identifiedthe pathogen type, screened for new resistant materials and hybrids and cultivated new resistant hybridsusing microspore culture and marker-assisted selection, which provides the basis for cabbage resistancebreeding as well as for CFW controlling. Secondly, in terms of basic research, we mapped and cloned the resistant gene and validated it using80cabbage inbred lines. This work paves the way for further function and mechanism analysis of theresistance gene.更多还原