河南省小麦赤霉病菌种群组成及致病力分化

Composition and variation in aggressiveness of Fusarium populations causing wheat head blight in Henan province

为明确河南省小麦赤霉病种群组成和致病力分化情况,2007—2014年对河南省15个市84个田块的327个小麦赤霉病菌进行种群鉴定、毒素化学型分析和致病力分化研究,结果表明:Fusarium graminearum s.str.和F.asiaticum是河南省小麦赤霉病的优势种群(97%),F.pseudograminearum(2.1%)、F.culmorum(0.3%)、F.equiseti(0.3%)、F.verticillioids(0.3%)为次要种群;对于禾谷镰刀菌复合群来说,豫北地区分布只有F.graminearum s.str.,豫中地区F.graminearum s.str.和F.asiaticum都存在,以F.graminearum s.str.为主,豫南地区F.graminearum s.str.和F.asiaticum都存在,以F.asiaticum为主;291个F.graminearum s.str.都为15ADON类型,26个F.asiaticum菌株中22个为3ADON,1个为15ADON,3个为NIV类型;F.graminearum s.str.(15ADON)也存在致病力分化,强、中、弱致病力的菌株在河南省的比例约为2:2:1。

For finding out the composition and aggressiveness variation in Fusarium populations causing wheat head blight in Henan province,three hundred and twenty-seven isolates of Fusarium spp.from diseased wheat spikes collected in 84 fields in 15 cities across Henan province during 2007 to 2014 were tested for species identification,deoxynivalenol chemotype and aggressiveness assay.The results indicated that F.graminearum s.str.and F.asiaticum（97%） are the main causal agents of Fusarium head blight in Henan province,whereas the remaining 2.1%of the isolates were identified as F.pseudograminearum,and F.culmorum,F.equiseti and F.verticillioids took up 0.3%of total samples,respectively.Among the isolates of F.graminearum species complex,F.graminearum s.str.isolates are prevalent in northern Henan province;F.graminearum s.str.and F.asiaticum were both distributed in its central and southern areas,and F.graminearum s.str.is a prevalent species in central Henan province,but F.asiaticum is prevalent in southern Henan province.All 291 F.graminearum s.str.isolates belong to the 15-acetyl deoxynivalenol type（15AD0N）,among the 26 F.asiaticum isolates,22 isolates were of the 3-acetyl deoxynivalenol type（3AD0N） while 3 isolates were the nivalenol（NIV） type and only 1 isolate was of 15-acetyl deoxynivalenol type.According to virulence tests,F.graminearum s.str.（15AD0N） isolates were divided into three kinds of virulence groups（weak,moderate and strong virulence）,the members in each group are 48,93 and 90 respectively.The ratio of them was approximately 1：2：2.