核盘菌(Sclerotinia sclerotiorum)在大豆叶片上致病过程的初步电镜观察

ELECTRON MICROSCOPY OF INFECTION OF SOYBEAN BY Sclerotinia sclerotiorum

通过电子显微镜观察核盘菌在大豆叶片上的侵染过程,初步发现该病菌首先在大豆叶表面上形成复合附着器。该附着器可能产生某些酶类软化溶解大豆叶表面,以帮助该病菌侵入叶片内。侵入叶片以后,该病菌既能在叶肉细胞间又能在叶肉细胞内生长。在此过程中,该菌仍借助于酶的分解作用破坏寄主组织,直至再突破叶面角质层,出现在叶面上。然后该菌在叶面上形成菌核。在大豆不同生育期,该病原侵染寄主大豆的速度有所不同。苗期最快,花期最慢。

Observation of infection process of soybean leaves by Sclerotinia sclerotiorum by using electron microscopy showed that the fungus formed appressoria on the leaf surface before their penetration through leaf cuticle. The appressoria were able to produce some enzyme (s) to modify the surface cuticle of soybean leaves in order to help their penetration. After the penetration, the pathogen could grow in mesophyll of soyben leaves both inter and intra-cellularly. During colonization , the enzymic modification of the mesophyll by the pathogen was also esenssial to disnite-grate soybean leaf tissue. Finally the fungus grew out of the leaf surface and formed sclerotia on the leaf surface.