小麦矮化腥黑穗病菌侵染能力的研究

中美专家合作在美国犹他州对小麦矮化腥黑穗病菌的侵染能力进行了研究。试验采用不含抗病基因的小麦品种Cheyanne,播种前用溴甲烷对试验小区进行了熏蒸。接种物为含有多种致病型的冬孢子悬浮液,采用土壤表面喷洒冬孢子悬浮液的方法进行接种,接种密度为每cm20、0.88、8.84、88.45、884.49、8844.89、88449个孢子。结果表明,接种密度为每cm20.88个孢子时即可产生0.21％的穗发病率。对试验数据进行分析后表明,小麦矮化腥黑穗病菌的侵染规律符合侵染概率理论,在本试验条件下,单个孢子的侵染概率为0.0002。

The infection capacity of the teliospores of Tilletia controversa Kühn

The infection capacity of the teliospores of Tilletia controversa Kuhn was studied in a joint research by Chinese and USA phytopathologists at Logan,Utah,USA. Before seeding,plots were fumigated with methyl bromide for two times to eliminate the possible residual teliospores in soil. A susceptible wheat cultivar,Cheynne,was seeded into eight 32-fts rows and the soil surface were inoculated by a special designed Mater-OSU sprayer with the inoculum density of 0,0.88, 8.84,88.45,884.49 and 8844.89 teliospores per square centimeter. The inoculum was consisted of a composite of pathogenic races and isolates from throughout the western United States. Another eight 8-fts rows was soil surface inoculated with 88449 teliospores per square centimeter as positive control. 0.21 % diseased spike incidence occurred at the inoculum density of 0. 88 spores per square centimeter. The results were analyzed showing that the infection of T. controversa conformed to the hypothesis of infection probability established by Vanderplank in 1975,and that, under the conditions of this experiment, the infection capacity of single teliospore was 0.0002.