Abstract: A few of Bipolaris eleusinea J.H.Peng et J.Y.Lu were isolated from Agropyron cristatum(L.) Gaertn.rhizome of the arid grasslands.This study focused on the morphological,biological,and cultural characteristic of B.eleusinea in order to understand its growth and development features and control the disease caused by B.eleusinea.The results show that the temperature range for the germination of B.eleusinea conidia was 5℃ to 40℃ with the optimum of 20℃ to 30℃.The conidia could germinate at a broad range of culture fluid pH value and the optimum pH was 4.53.The conidium germination was not sensitive to light and required liquid state water and the germination rate was only 3.2% at 100% relative humidity but not germinated below 100% relative humidity.5-and 10-times diluted soil suspension,sheep dung extractive solution,wheat root extractive solution,and sucrose solution inhibited the conidium germination,but 20 times diluted soil suspension and sucrose solution promoted the conidium germination.The suitable temperature range for hyphae growth was 10℃ to 40℃ with the optimum at 25℃.C-source from D-fructose,sucrose,or mannose and N-source from leucine or sodium nitirate significantly promoted hyphae growth but inhibited by D-Xylose or chloralose as the C-source and other nine N-sources.There were evident differences in colony configuration,e.g.color,size,and edge,among these C-and N-sources.This paper firstly reported that B.eleusinea infected A.cristatum in China and A.cristatum was a new host plant.

Key words: Agropyron cristatum(L.) Gaertn., Bipolaris eleusinea J.H.Peng et J.Y.Lu, Morphology, Cultural characteristic, Biological characteristics

摘要： 对冰草根际分离获得的蟋蟀草平脐蠕孢(Bipolaris eleusinea J.H.Peng et J.Y.Lu)的形态特征、培养性状及生物学特性进行研究,以期了解牧草根部平脐蠕孢菌的生长发育特点,并为该菌引起的牧草根病防治提供依据.结果表明:蟋蟀草平脐蠕孢分生孢子萌发的温度范围为5℃~40℃,适宜温度20℃~30℃;在各酸度下均能萌发,最适为pH 6.47;其分生孢子的萌发需要液态水,在相对湿度100%时分生孢子萌发率仅为3.2%,而相对湿度低于100%时孢子不萌发;低稀释倍数的土壤悬液、麦根浸出液、羊粪浸出液和蔗糖溶液[0]及高稀释倍数的麦根液和羊粪液均抑制孢子萌发,但高稀释倍数的土壤液和蔗糖液能促进孢子萌发;且孢子萌发对光不敏感.蟋蟀草平脐蠕孢菌丝生长的温度范围为10℃~40℃,最适25℃;碳源中D-木糖、氯醛糖对蟋蟀草平脐蠕孢菌生长具有明显抑制作用,而蔗糖、甘露糖和D-果糖对蟋蟀草平脐蠕孢菌丝生长具有明显促进作用;氮源中硝酸钠、亮氨酸对蟋蟀草平脐蠕孢菌丝的生长具有促进作用,而尿素等9种氮源均有抑制作用,并且此菌在含有各种碳、氮源的培养基上的菌落形态有差异.在国内首次报道此菌侵染冰草(Agropyron cristatum),为一新寄主植物.

关键词: 冰草, 蟋蟀草平脐蠕孢, 形态, 培养性状, 生物学特性