Identification of Pathogen Causing Meconopsis wilsonii Leaf Spot and Screening of Fungicides for Control
To determine the disease pathogen of Meconopsis wilsonii and its pathogenicity to different species of plants,and to screen the inhibitory fungicides.It provides a theoretical basis for the scientific prevention and control of M.wilsonii disease.Using the disease leaves of M.wilsonii collected from the seedling base of Southwest Forestry University as the experimental material,the strains were iso-lated and purified by the tissue isolation.Koch's rule was used to verify the pathogenicity of the strains and identify the strain species of M.wilsonii by morphological observation and molecular biol-ogy.And the pathogenicity of the pathogenic bacteria to different species of plants was determined u-sing the isolated leaf inoculation method to determine their host range,and the indoor toxicity of 50％Carbendazim,50％Azoxystrobin,38％Boscalid,50％Prochloraz mangnse,75％Chlorthalonil and 80％Mancozeb to pathogenic bacteria was determined by toxic plate method.The strains were purified from the disease leaves of M.wilsonii,among which the pathogen of M.wilsonii disease was LRH-2.Observe the colony cultured for 7 days were circular whorls,mycelium white,and fusiform conidia have 2-3 accessory filaments.Combined with the rDNA-ITS sequence analysis,a phylogenetic tree was constructed and the strain was found to be clustered in the same branch as Pestalotiopsis micros-pora(strain number:KT459349).Combining morphological characteristics and ITS sequence analy-sis,LRH-2 was identified as P.microspora.The pathogenicity of 24 species of plants from 21 families was determined by isolated leaf inoculation method,and the results showed that the pathogenic symp-toms of small spores on 13 species of test plants from 12 families appeared to varying degrees during the experimental observation period.The six elow-toxicity fungicides had inhibitory effect on LRH-2.The 50％Carbendazim and 38％Boscalid had more well inhibitory effect on LRH-2 with a concentra-tion(EC50)of 0.447 and 0.497 mg·L-1.The pathogenic fungus of M.wilsonii was clearly identified as P.microspora,and the host range of the pathogen is confirmed to be potentially pathogenic to some plants,and its adaptability to the environment is strong,and 50％Carbendazim and 38％Boscalid had good control effect against it.
万方数据
维普
