东北地区四种常见禾本科杂草病原真菌资源调查及其致病性测定

A survey of pathogenic fungi on four common gramineous weeds in northeastern China

为了解我国东北地区常见禾本科杂草病原真菌资源状况,于禾草生长季节对东北三省19个县市的稗草、狗尾草、马唐和虎尾草的发病情况进行了调查和采样。对病害样品用组织分离法分离获得186个真菌菌株,经形态学观察和rDNA ITS序列比对分析,鉴定到10个属的真菌。对其中分离率较高具代表性的或来自发病严重样品的31个菌株用人工接种法进行了致病性测定,明确了新月弯孢(Curvularia lunata)对稗草、狗尾草、马唐和虎尾草均有较强致病性,梭形凸脐蠕孢(Exserohilum fusiforme)和尖角凸脐蠕孢(E.monoceras)对稗草具有较强致病性,麦根腐平脐蠕孢(Bipolaris sorokiniana)、狗尾草平脐蠕孢(B.setariae)、嘴突凸脐蠕孢(E.rostratum)和链格孢(Alter-nariaspp.)对狗尾草具有较强致病性。不同菌株致病性有差异,一般来讲,对原寄主的致病性强于对其他寄主的致病性。研究结果丰富了禾草的病菌资源和信息,为真菌除草剂的研发奠定了基础。

In order to understand the resources of pathogenic fungi on common gramineous weeds in northeastern China, field survey and sample collection of diseases of the barnyard grass Echinochloa crusgalli, the green bristlegrass Setaria viridis, the crabgrass Digitaria sanguinalis and the fingergrass Chloris virgata were carried out in grass growing seasons. With the tissue isolation method, 186 fungal strains were obtained. Out of them 10 genera were identified by means of morphological observation and alignment of rDNA ITS sequences. Pathogenicity of 31 strains, with high isolating frequency or from severely diseased samples, was tested with artificial inoculation. Curvularia lunata showed stronger pathogenicity on barnyard grass, green bristlegrass, crabgrass and fingergrass. Exserohilum fusiforme and E. monoceras showed stronger pathogenicity on barnyard grass. Bipolaris sorokiniana, B. setariae, E. rostratum and Alternaria spp. showed stronger pathogenicity on green bristlegrass. Pathogenicity was variable between strains and generally stronger on the original host plant than on other plants. The results enriched culture resources and information about pathogenic fungi of gramineous weeds, which provided the foundation for the development of fungal bio-herbicides.