禾顶囊壳两个变种对草坪禾草的致病性比较

Comparative study on pathogenicity of Gaeumannomyces graminis var. avenae and G. graminis var. tritici to turf-grass

采用人工接种法测定了禾顶囊壳燕麦变种和小麦变种对主要草坪禾草的致病性。供试草种包括多年生黑麦草、一年生黑麦草、草地早熟禾、高羊茅、硬羊茅、细弱剪股颖、匍匐剪股颖和狗牙根等。结果表明 ,两个变种都引起全蚀病的典型症状 ,病株根系、根状茎、根颈和基部叶鞘等部位变褐色或黑色而腐烂 ,叶片黄化 ,植株瘦弱矮小。小麦变种的致病力与燕麦变种相当或略高。供试草种间发病程度明显不同 ,狗牙根、匍匐剪股颖和细弱剪股颖发病最重 ,多年生黑麦草较轻。在我国尚未发现燕麦变种 ,小麦变种发生亦不广泛 ,二者都具有检疫重要性。

Pathogenicity of Gaeumannomyces graminis var.avenae(Gga)and Gaeumannomyces graminis var.tritici(Ggt)to turf-grasses , was evaluated by seedling - inoculation method. The tested plants of turf-grass, including Lolium perenne, Lolium multiflorum,Poa pratensis, Festuca arundinacea, Festuca rubra, Agrostis tenuis, Agrostis palstriss and Cynodon dactylon, showed typical symptom of take-all after inoculation with both Gga and Ggt. The root, rhizomes,crown and first leaf- sheath of inoculated plants discolored and extensively rotted, the upper leaves became yellowing and the height of diseased plants remarkably reduced. It was evident that Ggt had high pathogenicity to tested turf-grass,which was equal to that of Gga and even higher. The disease incidence and severity of tested species and cultivars were obviously different. Agrostis tenuis, Agrostis palstriss, and Cynodon dactylon were the most susceptible,however, Lolium perenne was relatively resistant. Gga did not occurred in China yet and the distribution of Ggt was limited. Both of them were of quarantine importance.