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稻瘟病是我国水稻主要病害之一,六十年代以来,在生产上不断发现一些抗稻瘟病的品种,但在推广、栽种的过程中逐渐丧失了抗病性。为探明其丧失原因及防治对策,1976年起开展了全国稻瘟病菌生理小种的协作研究。四年来,先后用21个省、市、区的1739个单孢分离物对212个水稻品种进行了筛选测定,从中选出特特勃、珍龙13、四丰43、东农363、关东51号、合江18号和丽江新团黑谷7个品种为中国稻瘟病菌生理小种的鉴别品种,并从23个省、市、区提供的827个单孢分离物中鉴定出7群43个中国小种,其中以“ZG_1”小种分布最广,出现频率最高,是我国的优势小种。南方籼稻区和籼、粳稻混栽区的小种组成较北方粳稻区复杂,而籼型小种(在籼稻鉴别品种上为 S 反应的小种),主要分布在南方稻区。初步研究表明品种抗病性的丧失,主要是由于出现了能侵染该品种的新小种所致。不良的环境条件和栽培措施也是加速品种抗性丧失的一个不可忽视的因素。通过对同一病标样上分离的各单孢培养菌,同一单孢不同细胞发育而成的培养菌、同一分离物转管代次及单孢分离物接种后再分离菌的致病性变异观察,初步看到稻瘟病菌致病性虽有变异的情况,但多数情况是稳定的。同时,通过反复测定,初步选出一些较为稳定的分离物,为今后开展品种抗病性的基因分析提供了必要的条件。
Rice blast is one of the main diseases of rice in our country. Since the 1960s, some blast resistant varieties have been found constantly in production, but gradually lost their disease resistance during the promotion and planting. In order to find out the cause of its loss and prevention and control measures, collaborative research on physiological races of Magnaporthe grisea was carried out in 1976. In the past four years, 212 rice varieties have been screened with 1739 single-spore isolates from 21 provinces, cities and districts. Tebte, Zhenlong 13, SiFeng 43, Dongnong 363 and Kanto 51 7 hybrids of Hejiang 18 and Lijiang Xintiao Heigu were identified varieties of Chinese races of Magnaporthe grisea and identified 7 groups of 43 isolates from 827 isolates from 23 provinces, cities and districts One of the races in China, of which the races ZG_1 are the most widely distributed and the most frequently occurring races. The races of South China indica rice and indica rice and japonica hybrid rice were more complex than those of northern japonica rice. The indica races (S-reactive races on indica rice) were mainly distributed in southern rice area. Preliminary studies have shown that the loss of disease resistance is mainly due to emergence of new breeds that can invade the breed. Poor environmental conditions and cultivation measures are also an indispensable factor in accelerating the resistance loss of varieties. The pathogenicity of the isolated isolates of the same isolates and single spore isolates after inoculation of the same isolates from different cultures of the same single spore, , Preliminary see the pathogenicity of Magnaporthe griseus despite the variation, but in most cases is stable. At the same time, some relatively stable isolates were selected through repeated measurements, which provided the necessary conditions for future genetic analysis of disease resistance.