上海地区果树根癌病发生与土壤环境的关系

果树根癌病(致病菌为根癌土壤杆菌Agrobacterium tumefaciens)目前在上海地区大面积发生,严重危害桃(Amygdalus persicaL.)、梨(Pyrus bretschneideri Rehd.)、苹果(Malus pumila Mill.)等果树的生长。本文采用化学分析及微生物培养等方法,研究了上海地区桃树和梨树根癌病的发生与土壤因子(土壤含水量、pH值、有机质含量),土壤细菌以及与不同果树品种之间的关系。结果表明:土壤含水量、pH值、有机质含量、土壤中微生物的多样性和微生物总体数目与病害的发生没有显著的相关性,但是土壤中存在的个别菌种对病害的发生有显著的影响,初步分析显示Agrobacterium sp.和Bacillus sp.对根癌病的发生具有抑制作用,而Psuedomonas sp.对根癌病的发生可能具有一定的促进作用。同时不同果树品种的病害发生率之间有显著性的差异。

Relationship between soil environment and occurrence of crown gall disease in Shanghai

The crown gall disease is a bacterial disease induced by Agrobacterium tumefaciens, mainly harmful for fruit trees such as peach (Prunus persica L.) and pear (Pyrus bretschneideri Rehd.). Recently this disease has occurred in most area of shanghai, leading to decrease of the fruit production and affecting the growth of trees. Using the soil chemical analysis and microorganism culture methods, we investigated the effect of environment condition (soil type, pH, water and soil organic matter content), bacteria, and type of fruit trees on occurrence of the crown gall disease. The results showed that pH, content of water and organic matter, variety and total number of microorganism in soil have no significant effects on occurrence of the crown gall disease. However, some bacteria species such as Agrobacterium sp. Bacillus sp. and Psuedomonas sp. and fruit strains had effects on occurrence of the crown gall disease. Agrobacterium sp. and Bacillus sp. might have inhibitory effect on disease, while Psuedomonas sp. might stimulate occurrence of the crown gall disease.