不同油茶物种抗炭疽病的组织病理学初步研究

Preliminary Study on the Pathological Histology of Resistance to Anthracnose-Causing Fungus in Camelliae Species

用扫描电镜和光学显微镜观测油茶炭疽病菌(Colletotrichum came-lliae Massee)分生孢子在三种不同抗性的油茶物种叶表面的萌发习性及侵入途径。结果表明,抗病和感病物种间分生孢子的萌发率无显著差异,但芽管萌发的长度与油茶物种的抗病性呈正相关,附着胞数与油茶物种的抗病性呈负相关。组织病理学研究结果表明,抗性不同的油茶物种对于病程中各阶段出现的时间及反应的程度各不相同。在感病物种上病菌发育顺利,潜育期短;在抗病物种上病菌发育与菌丝扩展缓慢,病变组织的范围小。病变过程中,受浸染部位及附近的叶肉细胞普遍产生一种被番红染成红色的小颗粒状物质,该颗粒物质的产生可能与油茶物种的抗病性有关。

The germination and infection of conidia of anthracnosecausing fungus ( Colletotrichum camelliae Massee ) on three species of camelliae leaves were observed under scanning electron microscope ( SEM ) and bright-field microscopy. The results showed that the percentage and rate of conidia germination on the leaf surface of resistant and susceptible Camelliae species was not evidently different, but the length of germ tubes were positively correalated with disease resistance of the tested Camelliae species, the values of appressorium were negative with disease resistance of the tested Camelliae species. The pathological histology tests indicated that the various stages of pathologensis occured at different times and reacted in different degrees among Camelliae species of different disease resistance, the amount of hyphae and the area of the mycelial, colony in the resistant species were fount to be lower and smaller than that in the susceptible ones, and the latent period of infection in the susceptible species was shorter than that in the resistant ones. In the precesses of pathological changes in the disease-resistance species, a red granular substance was produced in the mesphyll cells infected and about mesophyll cells. It is suggested that the substance was correalated with disease resistance of the Camelliae species.