云南省玉米灰斑病菌差异性分析

Analysis of Cercospora zeina Differences in Yunnan Province

采用单孢分离方法,从云南省10个州(市)玉米灰斑病标本上分离到32个菌株,测定其抗紫外辐射能力和孢子大小,并利用SSR标记技术分析了菌株间的遗传多样性。结果表明,在海拔2000～2300,1800～2000,1600～1800和1000～1600 m采集的菌株,紫外辐射量为7.5 KJ/m2辐照1 h后,分生孢子萌发率分别为89.96%、74.15%、66.99%和46.36%;分生孢子长度分别为58.92、54.68、55.69、52.37μm,宽度分别为9.11、7.82、7.13、6.54μm,长×宽为41.78～67.04μm×5.76～9.43μm,菌株采集地海拔与抗紫外辐射能力和分生孢子宽度之间呈极显著性正相关,相关系数分别为0.5812(P≤0.01)和0.7485(P≤0.01),但分生孢子长度与海拔间相关性不显著。病菌的遗传背景存在很大差异,但与菌株来源地无关联。

By single-spore isolating method,32 strains of Cercospora zeina were isolated from the diseased maize leaves from 10 prefectures of Yunnan province to test their size and ultraviolet radiation resistance（URR） and their genetic diversity was analyzed using SSR markers.Their conidial germination rates were 89.96 %,74.15 %,66.99 % and 46.36 % when they exposed in 7.5KJ/m2 of UV-B light.Their spore lengths were 58.92,54.68,55.69 and 52.37 μm,and their spore widths were 9.11,7.82,7.13 and 6.54 μm with average size 41.78-67.04 μm×5.76-9.43 μm for the strains collected from 2000-2300,1800-2000,1600-1800 and 1000-1600 m altitudes above sea,respectively.The results showed that the altitude was most significantly and positively related to URR and spore width with relation coefficients of 0.5812（P≤0.01） and 0.7485（P≤0.01）,but not significantly to spore length.The pathogen had diverse genetic background unassociated with its collection sites.