Pathogen identification and cultural characteristics of leaf spot of Codonopsis pilosula
Morphological and molecular methods were combined to identify the pathogen of leaf spot of Codonopsis pilosula.Traditional cultural methods of plant pathology were used to test the cultural characteristics and a phylogenic tree was built through rDNA-internal transcribed spacer (ITS) sequencing.Pycnidia were spherical or sub-spherical,53.8-76.6 μm × 40.3-62.7 μm in diameter;conidia were hyaline,needle,one to four septate,15.3-38.8 μm × 0.9-1.2 μm in diameter.Phylogenic analysis of ITS confirmed that the pathogen was Septoria codonopsidis Ziling.The temperature ranges for hyphal growth,spore germination and production were 5-30,5-35 and 15-25℃,respectively,with an optimum temperature of 20-25,20 and 20℃,correspondingly.Continuous illumination facilitated hyphal growth and spore germination.Continuous darkness benefitted spore production.The pH ranges for hyphal growth,spore germination and production were 4.0-10.0,4.51-9.19 and 7.0-7.5,with an optimum of pH 4.5,7.0 and 7.5,respectively.The relative humidity for spore germination was above 90％.Spore germinated well in water.Root extract and dextrose solution stimulated spore germination.The optimum temperature for mycelium growth and spore germination of the pathogen was low,indicating that the disease would be severe under low temperature,wet and continuous rainy weather.
NETL
NSTL
万方数据
维普
