几个主要因子对水葫芦链格孢生长和侵染力的影响

测试引起水葫芦黑斑病的生防真菌水葫芦链格孢(Alternaria tenuissima)的主要生物学特性(培养基、温度、pH值对菌落生长以及光照对产孢量的影响)和影响该菌株侵染力的3个主要因子(接种温度、光照、保湿时间),以期为该菌的大量发酵和真菌除草剂的研制奠定基础.试验结果表明,培养基、温度和酸碱度是影响该菌生长的...

Effects of Some Major Factors on Growth and Pathogenicity of Alternaia tenuissima Causing Black Spot of Water Hyacinth

The effects of several major factors on growth(medium,temperature and pH),sporulation(illumination)and pathogenicity(inoculation temperature,illumination and moisture time) of Alternaria tenuissima,a biological control agent for water hyacinth,were investigated in the present study.Experimental results indicated that the best medium,temperature and pH were,respectively,PSA,25℃ and pH 9.0 for the fungus growth.UV light(12 h/d) was the most appropriate for its sporulation,and the spore production reached 3.44×105 per dish after 20 days.Temperature,light intensity and moisture were shown marked impacts on conidial germination and infection of the fungus.The highest disease intensity on the primary leaves at 21 days after inoculation and incubation at 30℃ reached 7.77,obviously higher than at 20℃ and 25℃.Moisture duration was shown an important factor affecting infectivity of the pathogen.95% inoculated leaves were infected and diseased after 4 weeks when they were maintained for more than 12 hours of wetness at 25℃,and the disease severity reached 5.21.High light intensity(3 000 lx) showed marked inhibitive effect on conidial germination and infection of the pathogen and thus resulted in lower disease severity than low light intensity(1 200 lx) on the plants.