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广谱抗病基因的利用是控制稻瘟病最有效和最经济的方法。来源于华南的地方稻种暹罗占对稻瘟病菌表现出广谱抗性,以普感品种丽江新团黑谷为轮回亲本选育的暹罗占近等基因系NIL-XLZ对测试的44个不同来源稻瘟病菌的抗性频率为84.4%,其抗谱优于广谱抗瘟基因Pi2、Piz,与抗瘟基因Pi9和Pi50相近。为进一步了解暹罗占抗稻瘟病的遗传基础,以感病品种广恢290为母本、暹罗占为父本,构建了广恢290/暹罗占的F2遗传分离群体。选取致病谱较广的稻瘟病菌代表菌株GD08-T19对来源于广恢290/暹罗占的F1与F2个体进行了抗病遗传分析,结果显示F1个体全表现抗病,1760个F2个体的抗感分离比率为4.06∶1,表明暹罗占至少含有一个显性的抗稻瘟病基因。利用分布于Pi2、Pi1、Pita座位附近的44对SSR引物,对构建的抗/感基因池及遗传分离个体进行了分析,将暹罗占含有的一个抗瘟基因定位于水稻第6染色体Pi2/Pi9/Pi50基因家族区域247 kb的范围内。抗菌谱分析、基因特异性分子标记检测及测序分析结果表明:暹罗占含有广谱抗瘟基因Pi50。本研究结果为暹罗占在水稻抗病育种上的应用提供了重要依据。
The utilization of broad-spectrum disease-resistance genes is the most effective and economical method to control rice blast. Siamese, a local rice species originating in South China, showed broad-spectrum resistance to Magnaporthe grisea, and the NIL-XLZ pair of the Siamese near-isogenic lines bred by recurrent parental variety Lijiang Xintuan Black Valley The resistance frequency of Magnaporthe grisea from different sources was 84.4%, which was superior to that of the broad-spectrum anti-plague genes Pi2 and Piz and similar to the anti-plague genes Pi9 and Pi50. In order to further understand the genetic basis of Siam’s resistance to rice blast disease, the F2 genetic segregation population of Guanghui 290 / Siam was constructed with the susceptible variety Guanghui 290 as female parent and Siam as male parent. The disease-resistant genetic analysis of F1 and F2 individuals from GD08-T19, a representative strain of Magnaporthe grisea with more pathogenicity spectrum, showed that F1 individuals were fully resistant and 1760 F2 individuals The anti-susceptible separation ratio was 4.06: 1, indicating that Siam occupies at least one dominant blast resistance gene. Using 44 pairs of SSR primers distributed around the Pi2, Pi1 and Pita loci, the constructed anti-sense gene pool and genetic segregation individuals were analyzed. One anti-blast gene contained in Siam was localized on Pi2 / The Pi9 / Pi50 gene family region is within 247 kb. Antibacterial spectrum analysis, gene-specific molecular marker detection and sequencing analysis showed that Siam accounted for a broad-spectrum anti-plague gene Pi50. The results of this study provide an important basis for the application of Siam in rice disease-resistant breeding.