抗水稻纹枯病qSB-9^(Tq)基因效应及作用方式分析  

Effect and Action Analysis of qSB-9^(Tq) Conferring Resistance to Rice Sheath Bligh

作　　者：殷跃军[1] 左示敏[1] 王辉[1] 张亚芳[1] 陈宗祥[1] 马玉银[1] 顾世梁[1] 潘学彪[1] 

机构地区：[1]扬州大学江苏省作物遗传生理重点实验室/植物功能基因组学教育部重点实验室,江苏扬州225009

出　　处：《作物学报》2009年第2期279-285,共7页Acta Agronomica Sinica

基　　金：国家高技术研究发展计划(863计划)项目(2006AA10Z165;2006AA10A103);公益性行业(农业)科研专项经费(nyhyzx07-049)资助

摘　　要：水稻第9染色体上存在1个抗纹枯病QTL,被命名为qSB-9,水稻品种特青在该QTL上携带抗性等位基因qSB-9Tq,而Lemont携带相对感病等位基因qSB-9Le。为精确地评价qSB-9Tq的抗病效应,分析其作用方式,利用分子标记进行前景选择和背景选择,从轮回亲本Lemont与特青回交后代群体中筛选到1个目标单株。连续3年对该单株的扩繁后代(BC6F2)及随后获得的近等基因系采用嵌入法进行接种鉴定试验。田间试验采取2种不同的设计。第一种是完全随机试验,即从BC6F2分离群体中筛选出目标区间为qSB-9TqTq纯合型、qSB-9LeLe纯合型和qSB-9TqLe杂合型个体,并对3种基因型个体间的病级平均数差异进行统计分析。第二种设计为随机区组设计,即在BC6F3和BC6F4代,分别对上述3种基因型的近等基因系群体,按3次重复的随机区组设计进行移栽和接种鉴定试验。结果表明,3年的试验结果表现出一致的趋势,即qSB-9Tq存在于分子标记RM242～Y92.5之间,可减轻病级1.0级(0～9级病情分级系统)左右,且其抗性表现为几乎完全的显性特征。本研究的结果为qSB-9Tq的精细定位和育种利用奠定了基础。A quantitative trait locus （QTL） contributing partial resistance to rice sheath blight （SB）, named as qSB-9, has been confirmed on chromosome 9 of rice. A rice cultivar, Teqing, possesses the relatively resistant allele, qSB-9^Tq, and Lemont has the relatively susceptible allele, qSB-9^Le. To evaluate the resistance effect and action mode of qSB-9rq accurately, a BC6F~ plant, from a backcross of Lemont （recurrent parent）/Teqing, with heterozygous genotype of qSB-9Tqz~ and similar genetic background to Lemont was screened out by using marker-assisted selection. Artificial inoculation with strong pathogenic Rhizoctonia solani line, RH-9, was conducted on the BC6F2 population and the near-isogenic lines （NILs） selected from BCtF3 and BC6F4 generation in a three-year test. Two experimental designs were adopted. One was completely randomized experiment, in which the plants with three genotypes （qSB-9^TqTq, qSB-9^LeLe, and qSB-9TqLe） on the locus of qSB-9 were distinguished by detecting marker genotypes flanking the qSB-9 in BC6F2 segregation population. The other was a randomized block design with 3 replicates for three NILs in BCtF3 and BCtF, generations. Results from the two experiments all suggested that the qSB-9rq was a dominant resistance allele in the interval between the markers of RM242 and Y92.5, and could reduce disease rating about 1.0 score under ＂0-9＂ SB-disease rating system. The result of the research laid a strong foundation for the fine mapping and breeding utilization of qSB-9rq.

关 键 词：水稻(Oryza SATIVA L.) 纹枯病 QTL 近等基因系 标记辅助选择 抗性效应 作用方式 

分 类 号：S511[农业科学—作物学]