【摘要】 从我国不同地区采集的玉米小斑病菌(Hclminthosporium maydis),通过温室苗期接种鉴定,及其产生的毒素对玉米种子根的抑制作用,发现76-527、76-528和76-529三个分离菌系在T型细胞质雄性不育系幼苗上产生萎蔫型大病斑,而在相对应的正常系以及M、C、CA、EK、D、PS型细胞质雄性不育系幼苗上则产生坏死型小病斑。其中76-529所产生的毒素,对T型细胞质雄性不育系种子根的抑制作用远远大于相对应的正常系,因此,初步认为这些分离菌系类似国外的T小种。而76-361和76-414两个分离菌系对T型细胞质雄性不育系则无上述的特异性。因此,初步认为这些分离菌系类似国外的o小种。更多还原

【Abstract】 When seedling of corn inbreds were inoculated with isolates 76-527,76-528, 76-529 of Helminthosporium maydis in the greenhouse, the seed-lings of inbred lines with T male sterile cytoplasm were more susceptiblethan those with normal (non-sterile) cytoplasm. There was no significantdifference between the other male sterile cytoplasm and the normal, however,difference in pathogenicity were expressed in both the form and the size ofthe lesion. The virulence of the toxins produced by the isolate 76-529 wasfar greater than that of the toxins produced by the isolate 76-361 in in-hibiting the growth of the primary roots of inbred(T male sterile).Thedifference in virulence showed that the two physiologic races (i. e. "T" and"O"races) of H.maydis are both existing in China.更多还原