摘要
对辣椒疫霉（PhytophthoracapsiciLeonian）在上海市郊蔬菜地土壤中的季节性变化和垂直分布进行了研究。结果表明，辣椒疫霉在一年中季节性的种群数量变化与温度的关系最密切，土壤中最多菌量出现的时间也是病原菌生长的最适温度（25～28℃）出现的时间，也正值该地的夏、秋季节。P．capsici在土壤中主要分布在地表10cm的土层中，10cm以下土层的菌量较少。当土壤中存有P．capsici的寄生植物时，P．capsici的数量比没有寄主时多，而且存活的时间也长，前者为18周，后者仅8周。无论是在湿润土壤中还是淹水的土壤中，由于孢子囊具有能抗不利环境条件的厚壁，故孢子囊存活时间均比游动孢子长。
We have studied the seasonal population fluctuation, vertical distribution andsurvival of P. capsici in vegetable field soil in Shanghai suburbs. The results indicated thatthe pathogen population peaks in fields coincided with the occurrence of optimum temperatures (25～28 ℃ )of the pathogen growth just in summer and autumn. Host debris in soil had apositive effect on population of P. capsici. Seasonal variation in population levels of P. capsiciwas closely related to temperature. The results of regression analysis showed that the seasonal fluctuation of P. capsici in soil related also to soil temperature and moisture. Thepathogens were mainly distributed in the ploughing layer of 0～10 cm. Tests of P. capsicisurviving in soil indicated that sporangia could survive for 18 weeks in soil with host debrisbut only for 8 weeks in soil without host debris; moreover,the sporangia could survive longerthan zoospores (4～5 weeks)due to the resistance to adverse conditions of thick walls of sporangia.
出处
《上海农业学报》
CSCD
1998年第4期45-50,共6页
Acta Agriculturae Shanghai
关键词
辣椒疫霉
土壤
季节性变化
存活
Seasonal fluctuation
Survival Phytophthora capsici
