Biological characteristics of the pathogen of Schisandra chinensis leaf blotch, Alternaria tenuissima.

The leaf blotch pathogen Alternaria alternate was purified from Schisandra chinens and its biological characteristics were studied.The results showed that mycelia grew fastest on medium PDA.Media PDA,PSA and JB were most suitable for spore germination.Temperature affected mycelia growth and spore germination significantly,fastest mycelia growth happening at 30℃,and highest spore germination rate happening at 25℃.The pathogen could grow under pH 2 to 12.pH 8 was most suitable for mycelia growth,and pH 6-7 was most suitable for spore germination.A dark condition was hyphal growth and spore germination.Maltose and fructose were the best carbon sources for the mycelia growth and spore germination.Peptone was the best nitrogen source for mycelia growth and spore germination.Different trace elements resulted in different effects on the mycelia growth and spore germination.Ca2+,Zn2+ were conducive to pathogen mycelia growth,and Na + was conducive to spore germination.