目的:观察灭蚊真菌贵阳腐霉产生类胰蛋白酶(Pr2)所需的诱导条件。方法:通过单因素诱导物、温度、pH值等比较试验摸索其产生Pr2的适宜条件。结果:贵阳腐霉产Pr2的适宜条件是在100 m l基本盐培养基中,以1%蝉蜕为唯一碳氮源,在26℃,初始pH值8.0,1%的菌丝接种量。结论:本研究初步确定的贵阳腐霉的Pr2产酶条件,为该酶的进一步研究提供了有价值的参考。
The aim of this study is to investigate whether Pythium guiyangense, a mosquito-killing fungus isolated in Guiyang, Guizhou Province of China in 1994, is pathogenic to plants. Six common crops, Cucumis sativa, Lycopersicon esculentum, Capsicum annuum, Nicotiana tabacum, Brassica campestris and Oryza sativa were used as subjects for test. Zoospores of the fungus were used to infect the plants with soil inoculation method, caudex injection method and foliage spray method. Both positive control (using P. aphanidermatum) and negative control (using sterile water) were set up in all the experiments. The results showed that no infection was found on the tested plants in soil inoculation experiments. In caudex injection test, callus grew around the wounded tissue in most of the plants. Brownish rottenness could be found only in the injected wounds in a few plants, probably caused by saprophytic bacteria or other fungi, and the germ-carrying plants grew normally. No abnormal appearance was found on the six crops in foliage spray test. It was demonstrated that P. guiyangense could hardly infect plants in nature, and was a safe and promising agent for mosquito biological control.
During the course of an outdoor experiment of mosquito biocontrol,a newstrain of fun-gus was isolated frominfected mosquito larvae,and identified as a newspecies of Pythium according to its morphological features as well as its DNA sequences of rDNA ITS region.Type specimen(driedculture) is deposited in HMAS,Beijing.
基于基因组DNA的真菌分类技术发展迅速。综述了DNA分子杂交技术,真菌线粒体DNA限制性片段长度多态性(m t RFLP)分析,随机扩增多态性DNA(RAPD)分析,rDNA序列分析,扩增片断长度多态性(amp lifiedfragm ent length polymorph ism,AFLP)在真菌分类和系统发育中的应用。
