本文对新疆鸭茅进行采样调查,发现在鸭茅的分蘖上长有真菌子座,子座圆柱状,成熟期为黄色,表面粗糙,子座长45~55mm;在PDA培养基上25℃培养2周后,菌落直径45~54mm,菌落正面白色,棉质,质地紧密,中央隆起或稍有皱褶,背面白色至黄色;菌丝体细长,分枝,分隔,不易产生分生孢子。在受到胁迫时产生孢子,孢子梗长13~33μm,基部宽2.7~4.1μm,顶端变尖小于1μm;分生孢子无色透明,椭圆形或肾形,单个顶生,(4.1±0.5)μm×(2.2±0.5)μm;为典型的Epichloё属真菌。利用碳源能力由强到弱依次为:蔗糖〉果糖〉葡萄糖〉淀粉。利用硝酸铵的能力最强,之后依次为蛋白胨和硝酸钾,具有分解酪蛋白淀粉能力。选择菌株Ed0907,利用rDNAITS序列分析构建了系统发育树,结果表明分离菌株(Ed0907)与Epichloёtyphina聚为一枝,相似率为100%。根据以上结果,确定分离菌株为Epichloё真菌。
Surveys conducted in Xinjiang revealed a Dactylis glomerata population infected by Epichloё endo-phyte.The conidial stroma on the grass tillers were waxy,yellow and 45 -55 mm in length.The endophyte was isolated and incubated on PDA (potato dextrose agar)medium for two weeks at 25℃.The diameter of col-onies ranged from 45-54 mm.They were compact,centrally raised with a white cottony mass of aerial hyphae and white to yellow on the underside.Hyphae were long with septum and conidia very sparse unless the colony was stressed.Conidiophores were hyaline,smooth,13 -33 μm long,2.7-4.1 μm at base and less than 1.0μm at the tip.Conidia were hyaline,oval to reniform and size ranged;(4.1±0.5 )μm ×(2.2 ±0.5 )μm. These dimensions are typical of Epichloёendophytes.The preference of these isolated Epichloёendophytes for carbon source was sucrose〉fructose〉glucose〉starch and for nitrogen sources,ammonium nitrate〉peptone〉potassium nitrate.These isolations exhibited differences in the hydrolysis of casein and starch.ITS sequence of isolation-Ed0907 was analysis and the phylogenetic tree constructed;it showed that the tested isolation clus-tered with Epichloёtyphina with 100% similarity rate.Based on these morphological,physiological and phylo-genetic characteristics,the endophyte isolated from D .glomerata was identified as Epichloёspp.