Identification,biological characteristics and control agents of the pathogen causing belladonna basal stem rot
The basal stem rot disease of belladonna(Atropa belladonna)occurred severely in the experimental farm of Shijiazhuang Academy of Agriculture and Forestry Sciences in May 2022.In order to effectively control the disease,identification,biological characteristics of the pathogen as well as disease control were carried out.The pathogen isolates causing belladonna basal stem rot disease was identified as Pythium aphanidermatum based on the morphological characteristics,rDNA-ITS sequence analysis and Koch's postulates testing.To our knowl-edge,the new disease is the first report in China.The optimum temperatures of mycelium growth,sporangium production and oospore formation were 35 ℃,25-35 ℃ and 35 ℃,the optimum pH values were 7.0-9.0,7.0-8.0 and 10.0,respectively.In addition,the optimum light condition and growth medium for culturing P.aphanider-matum were determined.The most suitable carbon sources of mycelium growth and sporangium production were soluble starch and glucose,and the most suitable nitrogen sources were ammonium nitrate and urea.Toxicity of nine chemical fungicides and one biological fungicide on mycelium growth of P.aphanidermatum were evaluated in the laboratory condition.The results showed that 35％metalaxyl-M FS,250 g·L-1 azoxystrobin SC,98％hy-mexazol SP and 100 g·L-1 cyazofamid SC had strong inhibition abilities against the pathogen with EC50 of 1.619,2.069,37.463 and 49.484 μg·mL-1,respectively.All the work mentioned above provided a basic knowledge for rational control of belladonna basal stem rot.
NETL
NSTL
万方数据
