The Biological characteristic of the root rot disease of summer squash pathogen Phytophthora nicotianae

Phytophthora nicotianare is the major plant pathogenic fungi that cause root rot disease in summer squash of Shanxi province.An approach of isolation,culture in laboratory was used to study the biological characteristic of Phytophthora nicotianare.The results showed that the optimum temperature of Phytophthora nicotianare for its growth and produce sporangium is 27℃,the pH is 6 and the culture medium is oat and had less produce sporangium in the dark.It had different degree of restrain effect when the CA culture medium was added with 5% different kinds of nitrogen,2% different kinds of carbon or the different concentration Cycocel.But 10μg/ml and 20μg/ml 2,4-D had accelerate effect.