2种麦冬炭疽病菌生物学特性的研究

Biological characteristics of 2 species of Colletotrichum causing Ophiopogon japonicus anthracnose

胶孢炭疽菌和黑线炭疽菌是麦冬炭疽病的病原菌。胶孢炭疽菌菌丝体生长、产孢和孢子萌发的最适温度都为28℃,黑线炭疽菌的分别为25,28和25℃。弱酸条件有利于2种炭疽菌菌丝体的生长和产孢,在pH值为4时产孢量都达到最大值,胶孢炭疽菌在pH值为7时孢子萌发率最大,黑线炭疽菌在pH值为8时达最大。光照处理对这2种病菌营养生长和产孢均无显著影响。供试碳源中果糖和葡萄糖有利于胶孢炭疽菌的菌丝体生长,山梨糖和淀粉有利于其产孢;麦芽糖有利于黑线炭疽菌的菌丝体生长,淀粉有利于其产孢;氮源中有机氮有利于2种炭疽菌生长和产孢,化学氮源则表现抑制作用。胶孢炭疽菌和黑线炭疽菌的致死温度分别为55和50℃10 min。

Colletotrichum dematium and C. gloeosporioides cause anthracnose of Ophiopogon japonicus. The optimum temperatures for mycelial growth, sporulation and spore germination of C. gloeosporioides was 28℃, 28℃, and 28℃, respectively and those of C. dematium were 25℃, 28℃, and 25℃. The optimum pH for mycelial growth of C. gloeosporioides and C. dematium was 5-8, and that for sporulation of both fungi was 4. The optimum pH for spore germination of C. gloeosporioides was 7, and that of C. dematium was 8. Light treatments had no significant effect on mycelial growth or sporulation. C. gloeosporioides mycelium grew well on media with fructose and glucose as carbon source while sorbose and starch promoted sporulation. The mycelia of C. dematium grew well with maltose as carbon source while starch promoted sporulation. Of the nitrogen sources tested, organic nitrogens were beneficial for both mycelial growth and sporulation but chemical nitrogens suppressed both growth and sporulation. The TDP of C. gloeosporioides and C. dematium was 55℃ and 50℃ for 10 min respectively.