东农415稻瘟病抗性遗传分析及基因定位

 粳稻品种东农415自育成以来一直以其早熟、抗病、高产特性而著称,在黑龙江省稻瘟病高发区种植20多年均表现高抗稻瘟病。本研究利用158个采集于黑龙江省不同稻区的稻瘟病菌株对东农415进行接种鉴定,结果表明东农415对黑龙江省稻瘟病菌株有很强的抗性,抗谱高达89.2%。以东农415与丽江新团黑谷(LTH)杂交衍生的F₁和F₂群体为遗传分析试验材料,通过接种鉴定,发现东农415对稻瘟病菌株F-10-11的抗性由一个显性基因控制。进一步采用分子标记结合隐性群体分离分析法,以对菌株F-10-11极端感病的99个F₂单株为作图群体,将东农415的抗病基因定位在第2染色体,距离基因两侧标记RM5300和RM213的遗传距离分别为7.6和3.0 cM,暂命名为Pi-dn(t)。将Pi-dn(t)位点映射到水稻参考基因组图谱上,在抗病位点基因组区段内发现3个编码基因Os02g56010、Os02g55540和Os02g56400具有抗病基因结构域,可作为Pi-dn(t)的候选基因。

Genetic analysis and gene mapping of rice blast resistance in cultivar Dongnong415

Dongnong415 is well known for early maturity, diseases resistance and high yield since breeding, and has a high level blast resistance after cultivating more than 20 years in high incidence area of rice blast in Heilongjiang province. The evaluation of Dongnong415 for its resistance against 158 blast isolates collected from different rice cultivated regions of Heilongjiang province showed that this cultivar can resist 89.2% of all tested isolates, indicating that Dongnong415 has a broad-spectrum blast resistance. F-10-11 was used as the test isolate, and the genetic analysis of Dongnong415 by inoculating F₁ and F₂ populations derived from a cross of Dongnong415×LTH, showed that the resistance of Dongnong415 to the isolate was controlled by a single dominant gene. We constructed a mapping population consisting of 99 susceptible F₂ plants to isolate F-10-11. The resistance gene of Dongnong415, temporarily named as Pi-dn(t), was mapped at a region beween RM213 and RM5300 with 3.0 and 7.6 cM genetic distances in chromosome 2 based on molecular markers and BSA-RCA strategy. Pi-dn(t) loci were mapped in rice reference genome, and three coding genes with the domain structure of disease resistance Os02g56010, Os02g55540 and Os02g56400 were founded in the genome segment of resistance loci. The three genes can be used as resistant candidate genes for Pi-dn(t).