水稻抗稻瘟病基因Pi35功能性分子标记的开发及其应用

Development and Application of a Functional Marker of the Blast Resistance Gene Pi35 in Rice

稻瘟病是水稻生产上的严重病害,利用抗病基因培育抗病品种是控制稻瘟病最经济而有效的措施。在日本,稻瘟病部分抗性基因Pi35作为广谱持久抗性基因已广泛应用于水稻育种和稻瘟病防治实践。但是,Pi35基因在我国的资源和品种中的分布情况不清,制约了这一重要基因在我国育种实践中的应用,急需开发实用的分子标记,并系统研究该基因在我国的品种及其亲本中的分布情况,为稻瘟病抗性育种服务。本研究通过比对抗、感品种中Pi35等位基因序列,发现一个能检测抗、感病性差异的特异SNP(3780 T),并据此开发了Pi35基因的功能性分子标记Pi35-d CAPS。利用该标记检测了抗源藤系138的衍生品种10份、微核心种质204份和主栽品种67份,结合测序鉴定,确认5份藤系138衍生品种(垦鉴稻3号、垦鉴稻6号、垦稻8号、绥粳3号和龙粳34)及2份微核心种质(粳稻品种抚宁紫皮粳子和籼稻品种细麻线)携带Pi35基因。本研究结果为通过分子育种手段高效利用Pi35基因改良我国水稻(特别是籼稻)品种的稻瘟病抗性提供了手段。

Rice blast is one of the most destructive diseases, and breeding resistant cultivars is considered to be the most eco- nomical and effective strategy to control this disease. The Pi35 gene shows partial resistance to leaf blast and has been used as a broad-spectrum and durable resistance source in rice breeding programs in Japan. However, its distribution is not clear in Chinese rice germplasm and cultivars. For the purpose to facilitate the application of Pi35 in rice breeding programs in China, we com- pared the coding sequences of Pi35 alleles in multiple resistant and susceptible rice cultivars, found a specific nucleotide 3780T which was only present in the fimctional resistance allele of Pi35, and further developed a Pi35 functional marker （Pi35-dCAPS）. Among 281 rice accessions including 10 Fukei 138-derived japonica cultivars, 67 leading cultivars, and 204 accessions of rice mini-core collection of Chinese germplasm, five Fukei 138-derived cultivars （Kenjiandao 3, Kenjiandao 6, Kendao 8, Suijing 3, and Longjing 34） and two mini-core accessions （japonica cv. Funingzipijingzi and indica cv. Ximaxian） were detected to possess the intact Pi35 gene by using the Pi35-dCAPS marker in combination with the genomic sequencing of Pi35. These results will greatly facilitate the utilization of Pi35 in rice breeding programs by marker-assisted selection.