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近年来,在我国河南、山东、江苏、安徽、河北、湖北省发生的甘薯根腐病,经分离鉴定,主要致病菌为爪哇镰孢(Fusarium javanicum koord),爪哇镰孢根生变种(F.javanicum var radicicola),茄病镰孢兰色变种(F.Solani var.coeruleum),其中以爪哇镰孢致病力最强,出现频率也高。另外,在病根中还常分离到串珠镰孢胶孢变种(F.moniliforme var.subylutinans),串珠镰孢(F.moniliforme sheldon),尖孢镰孢(F.oxysporium Schlecht),菜豆壳球孢(Macrophomina phaseoli(Maubl.)Ashby),它们在单独回接时致病力弱或不致病。在河南省分离得到了Fusarium javanicum koord的典型菌株,在实验室条件下能经常产生子囊阶段甘薯隐赤壳(Hypomyces ipomoeae(Hals)Wr.),证明这个种在中国是存在的。甘薯根腐病又称烂根病,七十年代初相继在山东、河南、江苏、安徽、河北、湖北、陕西等省发生,是甘薯的一种新的毁灭性病害。主要症状为烂根,多从纤维根的尖端或中部开始,形成黑色病斑,尔后大部分黑色腐烂;有时病菌也能害插入土内的茎部,形成黑色病斑,严重时常使基部1—2个叶节黑色腐烂。病株一般不结薯,轻的虽结薯但薯块畸形,病斑部凹陷,表面有纵横龟裂,易脱落。病株地上部表现为叶小、较厚、发脆、有时反卷,节间缩短, 不发棵,叶片自下而上地脱落。有些品种如胜利百号的病株,入秋后就大量开花。此病近年来在河南省每年发病面积在一百万亩左右,一般减产三、四成,重病田常绝收,对甘薯生产造成严重威胁。面临一种新出现的病害,弄清病原对防治实践来说十分重要,为此,我们自1976年起,进行了这项研究工作。
In recent years, the root rot of sweet potato in Henan, Shandong, Jiangsu, Anhui, Hebei and Hubei Province has been isolated and identified. The main pathogens are Fusarium javanicum koord, F .javanicum var radicicola, F.Solani var. coeruleum, of which Fusarium graminearum has the strongest virulence and frequency of occurrence. In addition, Fusarium moniliforme var. Subylutinans, F. moniliforme sheldon, F. oxysporium Schlecht, Macrophomina phaseoli (Maubl.) Ashby), which are virulent or non-pathogenic when taken back alone. A typical strain of Fusarium javanicum koord was isolated in Henan Province. Hypomyces ipomoeae (Hals) Wr., An ascus stage, was often produced under laboratory conditions, indicating that this species is present in China. Sweet potato root rot, also known as rotten root disease, occurred in Shandong, Henan, Jiangsu, Anhui, Hebei, Hubei and Shaanxi provinces in the early 1970s. It is a new devastating disease of sweet potato. The main symptoms of rotten roots, mostly from the tip of the fiber root or middle to form a black lesion, most of the black afterward decay; sometimes bacteria can damage the stem inserted into the soil, the formation of black lesions, often severe basal 1- 2 leaves black rot. The diseased plants are generally not potato, although light tuber potato tubercle deformity, lesion depression, the surface has vertical and horizontal cracks, easy to fall off. The upper part of the diseased plants showed small leaves, thick, crisp, sometimes rewinding, internodes shortened, no trees, the leaves fall off bottom to top. Some species, such as victory hundreds of diseased plants, blooming after a large number of autumn. In recent years, the disease in Henan Province, the annual incidence of about one million mu area, the general reduction of three or four into, seriously ill often received, the sweet potato production poses a serious threat. Facing a newly emerging disease and clarifying the pathogen is very important for prevention and control practices, we have conducted this research since 1976.