小麦条锈菌新小种流行预测研究

 1986-1990年，采用病菌致病性测定、毒性基因分析、相对寄生适合度测定和品种布局调查等方法，对小麦条锈菌新小种流行预测进行研究。结果指出：1987年，与流行小种25号（19.3%）相比，1985年新发现的小种29号的出现频率仅9.5%，但它的致病范围广、毒性基因谱宽、相对寄生适合度值高、哺育品种面积达7000万亩，预测29号小种将发展为主要流行小种，这与1988年鉴定结果为优势小种(28.0%)完全一致。1990年基于条中29号频率达40.3%，感病品种面积超过1亿亩，秋苗菌源多和气候条件适宜等因素，对该年条锈病大流行做了准确预报。为抗病育种、品种布局和条锈病流行的长期测报提供了科学依据。这在理论和实际上都有重大意义。

STUDIES ON THE EPIDEMIC FORECAST OF NEW RACE OF WHEAT STRIPE RUST IN CHINA

Investigation on the epidemic forecast of new race of wheat stripe rust (Puccinia striiformis West.) was carried out during 1986-1990 through determination of the pathogen pathogenicity and the relative parasitic fitness, analysis of the virulent genes. and survey of the deployment of the commercial varieties. The new race CYR-29 was firstly discovered in 1985. In 1987, the frequency of this race was only 9.5%, while the dominant race CYR-25 was 19.3%. By means of analysing the feature of CYR-29 with more extensive range of pathogenicity to some wheat varieties, wider spectrum of the virulent gene, higher value of the relative parasitic fitness to the important commercial varieties and larger area of the breeding varieties (up to 70 million mu), it was predicted that CYR-29 would become the dominant race in 1987. It was demonstrated that the prediction was identical with the results of race identification in 1988. Based upon the fact that the frequency of CYR-29 was 40.3%, and the area of its infected varieties was more than 100 million mu, and there was a large amount of inocula in autumn seedling stage and suitable condition of weather in 1990, it was accurately predicted that wheat stripe rust would occur on a large scale in that year, which provided scientific basis for breeding resistant varieties, reasonable overall arrangement of varieties and long-term forecast of stripe rust epidemic, and also had a great significance in terms of theory and practice for wheat stripe rust control.