二十二个抗稻瘟病基因在云南的利用价值评价

为了明确22个抗稻瘟菌基因在云南省的抗性水平及其利用价值,将采集、分离自云南省3个稻区的282个稻瘟病菌单孢菌株,接种于以丽江新团黑谷为轮回亲本培育而成的含有22个垂直抗性基因的水稻单基因系上.根据各稻区采集的菌株在水稻单基因系上的侵染率,分析出各垂直抗性基因在云南省各稻区的利用价值.持有Pi9、Piz5、Pi1、Pita2、Piz、Pikh、Pizt 7个垂直抗性基因的单基因系的侵染率分别为1.22%、2.40%、3.21%、4.82%、5.95%、7.23%、9.04%,可在籼稻区种植或作抗源使用;持有Pi9、Piz5、Pi1、Pita2、Piz、Pikh、Pizt、Pi12、Pita、Pib 10个垂直抗性基因的单基因系的侵染率分别为0.93%、 16.67%、10.19%、 5.09%、15.74%、15.74%、12.04%、9.26%、19.29%、11.11%,可在粳稻区种植或作抗源使用;持有Pi9、Piz5、Pi1、Pita2 4个垂直抗性基因的单基因系的侵染率分别为8.60%、13.83%、10.93%、18.04%,可在籼粳交错区种植或作抗源使用.同时用联合致病性系数和联合抗病性系数分析了病菌和单基因系的群体互作以及抗瘟组合的利用价值,结果表明:品种两两搭配后的RAC值大于0.80的组合有Pi9与Pita2、Pizt、Pi1、Piz,说明以上4种组合的抗病性最强,应用价值最大.

Evaluation of twenty-two blast resistance genes in Yunnan using monogenetic rice lines

In order to evaluate performance of rice blast resistance genes in Yunnan Province,282 mono- conidia strains were inoculated on 22 monogenic rice lines raise by IRRI.The value of resistance genes were analyzed by calculating virulence frequency in three rice-growing regions,the results showed that, the virulence frequency on rice monogenic lines with Pi9,Piz~5,Pi1,Pita~2,Piz,Pik~h,Piz~t were 1.22%, 2.40%,3.21%,4.82%,5.95%,7.23%,9.04 % in indica-grown region,respectively;The virulence frequency on rice monogenic line with Pi9,Piz~5,Pi1,Pita~2,Piz,Pik~h,Piz~t,Pi12,Pita,Pib was 0.93%, 16.67%,10.19% ,5.09%,15.74%,15.74%,12.04%,9.26%,19.29%,11.11% in japonica-grown region,respectively;The virulence frequency on rice monogenic line with Pi9,Piz~5,Pi1,Pita~2 was 8.60%,13.83%,10.93%,18.04% in japonica-indica interleaving rice,respectively.Based on the vir- ulence frequency in three different regions,the rice cuhivars containing corresponding resistance genes could be rationally deployed.At the same time,the interaction on rice monogenic lines and blast fungus and the value of combinations with multiple resistance genes could be analyzed through pathogenicity as- sociation coefficient (PAC) and resistance association coefficient (RAC),which demonstrated that the RAC of combinations of Pi9 and Pita~2 ,Pi9 and Piz~t ,Pi9 and Pi1,Pi9 and Piz was more than 0.80,and they behaved in higher resistance in Yunnan Province.