稻纵卷叶螟根虫瘟霉的分离鉴定及其流行病研究  

Zoophthora radicans infecting larvae of Cnaphalocrocis medinalis and its epizootic

作　　者：贾春生[1] 洪波[2] 

机构地区：[1]韶关学院英东生物工程学院,广东韶关512005 [2]韶关学院外事处,广东韶关512005

出　　处：《菌物学报》2012年第3期322-330,共9页Mycosystema

基　　金：国家自然科学基金(No.39870647)

摘　　要：在广东省发现一种新的侵染稻纵卷叶螟幼虫的昆虫病原真菌,经鉴定该病原真菌为根虫瘟霉Zoophthora radicans,这是中国首次报道该菌侵染稻纵卷叶螟。在室内进行的温度和光周期对该菌生长的影响实验表明,该菌在15-25℃均可生长,最适生长温度为25℃;光周期对菌落生长影响不显著。根虫瘟霉主要侵染稻纵卷叶螟3-5龄幼虫,对3-5龄幼虫的侵染率分别为2.71%、24.32%和72.97%。在10-11月,根虫瘟霉可持续引发稻纵卷叶螟幼虫高强度流行病,侵染率高达95%。该菌以休眠孢子越冬,成为次年稻纵卷叶螟幼虫流行病的初侵染源。因此,根虫瘟霉是稻纵卷叶螟幼虫一种有效的自然控制因子。A new fungal pathogen infecting larvae of Cnaphalocrocis medinalis was found during a survey of pathogens of the insect in Guangdong, China in 2006. The fungus was cultured in vitro and was identified as Zoophthora radicans. This is the first report of Z. radicans infecting larvae of C. medinalis in China. The effects of temperature and photoperiod on radial growth of the fungus were studied in the laboratory. The results showed that the optimum temperature for mycelial growth was 25℃ though it could grow at 15-25℃, and the photoperiods also affected insignificantly on mycelial growth. The fungus mainly infected the 3rd, 4th and 5th instar larvae and the infection rates were 2.71%, 24.32% and 72.97%, respectively. The epizootics of the fungus was consistently high during October-November, with infection rate reaching95%. The pathogen could survive during unfavourable season in rice field habitat in the form of resting spores and initiated epizootic in the following year. Thus, the fungus acted as a successful natural suppression agent of the leaf folder population.

关 键 词：根虫瘟霉 温度 光周期 虫霉目 稻纵卷叶螟 

分 类 号：S435.112.1[农业科学—农业昆虫与害虫防治]