【摘要】 试验2002～2004年在蒲江病圃和室内进行,发现不同组合及其恢复系对稻瘟病菌确实具有不同的抗性,2004年20个主要杂交水稻恢复系接种118个稻瘟病菌株后,所有菌株均至少对5个恢复系具有致病力,不同菌株间的致病力分化,使得同一田块病菌群体获得了对其他不同品种的致病力,其中对全部参试恢复系致病菌株出现频率为11 90%,显著高于仅对一个恢复系致病的菌株频率(P 0 01),水稻多样化抗性逐步为病菌所克服。利用pot2 1和pot2 2引物,对68个对多恢1号致病菌株rep PCR扩增获得多种指纹图谱,各菌株指纹图谱与其地区和品种来源无相关性,表明对多恢1号致病的菌株是由不同遗传背景的菌株演化而来。更多还原

【Abstract】 Field experiments in Pujiang county,Sichuan and laboratory inoculation of the isolates collected from the whole Sichuan province during 2002-2004 indicated that the changes in the population pathogenecity of the fungus to the hybrid rice were observed.After the inoculation of 118 isolates collected in 2004 on 20 tested restoring lines, at least 5 lines were infected by each isolate and 11.90 % of the isolates were virulent to all of the 20 lines. The differences in the virulent spectrum to different hybrid rice combinations between the isolates from the same paddy fields enabled the pathogen population to infect neighboring fields with different cultivars. The rice blast fungus could overcome the different resistance of various hybrid rice combinations planted in Sichuan. The electrophoresis pattern of the products of the Rep-PCR amplification of the DNA from the 68 isolates virulent to Duohui No.1 indicated the virulent isolate had multiple genetic backgrounds.更多还原