Abstract: Rust is one of the most important diseases that harms orchardgrass. In order to clarify the pathogen species， physiological characteristics and toxicity of Dactylis glomerata rust in Sichuan （Ya'an） and Chongqing （Fengdu， Qianjiang and Rongchang）， a total of 7 representative samples （3 strains of PD， PD1， PD2 in Rongchang area， 2 strains of PD3， PD4 in Ya'an， 1 strain of PD5 in Fengdu and 1 strain of PD6 in Qianjiang） were selected from the collected samples in Rongchang area for morphological and molecular biological identification. Seven pathogens were identified as Puccinia graminis. The biological characteristics of rust fungi were studied from 4 aspects： temperature， pH， light and nutrients. The results showed that the optimum temperature and pH for urediospore germination was 20℃ and 7 for 12 h. The germination rate was ranged from 91.86% to 93.04%. 0.1% sucrose could promote the germination of spores within 8 h， and 20% juice could inhibit the germination of spores. Light conditions had no significant effect on the germination of urediospores. Temperature of 40℃ for 10 min was lethal to urediospores. At the same time， it was found that there were four physiological races in this area. Among them， the frequency of type I was 40.91%， which was the dominant physiological race of orchardgrass rust in this area.

Key words: Orchardgrass, Biological Characteristics, Puccinia graminis, Isolation and identification

摘要： 锈病是危害鸭茅最重要的病害之一。为明确四川（雅安）和重庆（丰都、黔江和荣昌）地区鸭茅（Dactylis glomerata）病的病原菌种类及其生理学特性和毒性，以荣昌区为试点，从已采集样品中挑选具有代表性样品（荣昌地区3株编号PD、PD1、PD2，雅安2株编号PD3、PD4，‘丰都1株’编号PD5和‘黔江1株’编号PD6）共7株病原菌进行形态学和分子生物学进行鉴定，7株病原菌均为禾柄锈菌（Puccinia graminis）。从温度、pH、光照、营养物质等4个方面研究锈菌的生物学特性结果表明：夏孢子萌发的最适宜温度和pH分别为20℃、7，12 h的萌发率为91.86%至93.04%；0.1%的蔗糖对8 h内孢子的萌发有促进作用，20%的榨汁能抑制孢子的萌发；光照条件对夏孢子的萌发影响不显著；40℃处理10 min能使夏孢子死亡。因此，该地区共存在4个生理小种，其中，Ⅰ型出现频率为40.91%，是该地区鸭茅锈病的优势生理小种。

关键词: 鸭茅, 生物学特性, 禾柄锈菌, 分离鉴定