论文部分内容阅读
五年来,采用中国稻瘟病菌鉴别品种,将本省35个县(市)的470个单孢菌株,鉴定为七群15个中国小种。其中以 ZE、ZF、ZA、ZD 四群为主要菌群;以 ZE_1、ZF_1小种出现频率高,分布广,为我省优势小种。优势较强的还有 ZD_1、ZG_1、ZA_(49)以 ZA_(17)、ZD_1为致病性最强的小种。我省小种组成虽较复杂,种类亦多,但仍以粳稻上长期存活下来的只能侵染粳稻鉴别品种的生理小种为主。同时,据生理小种不同类群的致病性与品种抗病性的关系分析,证明水稻品种抗病性丧失原因主要是出现了能侵染该品种的新小种所致。高抗品种京引59抗病性突然丧失,主要与 ZA、ZE 两群小种的出现和增殖有关;普选十号成为感病品种,是 ZE_1小种增殖所致;抗病性较强又稳定的合江二十号,近年来抗病性明显减弱,主要是致病性强的ZA 群小种侵染的结果。说明我省稻瘟病菌生理小种的消长与品种抗病性关系密切,致病性强的 ZA 群小种不仅存在,并在适宜条件下,能导致粳稻品种突然丧失抗病性。
In the past five years, 470 M. monocytogenes strains from 35 counties (cities) of the province were identified as seven populations of 15 Chinese race breeds using the Chinese Magnaporthe grisea differential strain. ZE, ZF, ZA, ZD four groups as the main flora; to ZE_1, ZF_1 races appear high frequency, wide distribution, the advantages of race in our province. ZD_1, ZG_1, ZA_ (49) with ZA_ (17) and ZD_1 are the strongest ones. Although the races in our province have more complex races and more varieties, the racial races that can survive only on japonica rice can only infect the identification varieties of japonica rice. At the same time, according to the analysis of the relationship between the pathogenicity of different races and the disease resistance of races, it was proved that the main reason for the loss of disease resistance of rice cultivars was the emergence of new races that could infect the races. The disease resistance of Jingyin 59, a mutant with high resistance, was suddenly lost, mainly related to the appearance and proliferation of two races of ZA and ZE. It was caused by the proliferation of ZE_1 races in general election No.10 and the disease resistance was strong and stable Hejiang No. 20, in recent years significantly weakened disease resistance, mainly ZA group of pathogenic bacteria caused by small-scale infection. The results showed that the growth and decline of physiological races of Magnaporthe grisea in our province are closely related to the disease resistance of the cultivars. The ZA group of races with strong pathogenicity not only existed, but also caused the sudden loss of disease resistance of japonica varieties under appropriate conditions.