紫外线诱变对小麦条锈菌致病性突变的影响

EFFECTS OF ULTRAVIOLET RADIATION ON PATHOGENICITY MUTATION OF Puccinia striiformis f. sp. Tritic

为深入了解紫外线对小麦条锈菌致病性突变的影响,用不同时间的紫外线处理小麦条锈菌条中23-2,当夏孢子致死率达90%左右时确定为最适诱变剂量,为5min。紫外线处理条中23~25min得到2个突变菌株：在尤皮Ⅱ号上表现3型的菌株和在水源11上表现2型的菌株,分别命名为尤Ⅱ-23菌株和水源11菌株,其中尤Ⅱ-23菌株经4代转接仍保持毒性,水源11菌株经2代转接后发生回复突变。尤Ⅱ-23菌株在鉴别寄主上的反应型与野生菌系相比发生了较大变化,在测试品种上的毒性范围仅次于条中32号。对野生菌系和突变菌株进行RAPD分析发现,两者间的DNA多态性存在明显差异,多态率为10.73%。为进一步研究小麦条锈病的流行规律和致病性变异机制奠定了基础。

Urediospores of CY 23-2 were treated by ultraviolet with different radiation time. Five minutes were determined the proper radiation time, because the relative lethality rate of urediospores reached to 90% under this radiation dosage. Two mutant strains were obtained from urediospores of CY 23-2 which was treated 5min, named Jubilejina 2-23 isolate and Shuiyuan 11 isolate respectively. Jnbilejina 2-23 isolate still kept its virulence after stabilization for 4 generations, however Shuiyuan 11 isolate occurred reverse mutation after two generations. The ability for identification of host of Jubilejina 2-23 markedly changed compared with wild strains, and the pathogenicity of Jubilejina 2-23 just weaker than CY32. The DNA polymorphisms of Jubilejina 2-23 isolate, which polymorphic rate reached 10.73 %, was significant difference from CY23-2. The present study laid a foundation for further study of the prevalent rules and the mechanism pathogenic mutation of wheat stripe rust.