三七根腐病病原及复合侵染的研究

ON THE COMBINED INFECTION OF ROOT ROT PATHOGENS ON PANAX NOTOGINSENG

从三七根腐病不同发病期根部分离到假单胞杆菌Ｐｓｅｕｄｏｍｏｎａｓｓｐ．、腐皮镰孢Ｆｕｓａｒｉｕｍｓｏｌａｎｉ、细链格孢Ａｌｔｅｒｎａｒｉａｔｅｎｕｉｓ和小杆线虫Ｒｈａｂｄｉｔｉｓｅｌｅｇａｎｓ。活体接种假单胞杆菌的致病性最强，腐皮镰孢和细链格孢的致病性弱，小杆线虫无致病性。假单胞杆菌、腐皮镰孢和细链格孢混合接种的发病率都高于单独接种的发病率，尤以３种菌混合接种的发病率最高，含细菌的组合发病率高于不含细菌的发病率，说明细菌在侵染中起了主要作用。

Pseudomonas sp., Fusarium solani, Alternaria tenuis and Rhabditis elegans were isolated from root rot of Panax notoginseng (Sanqi) at different developmental stages. In inoculation test, Pseudomonas sp. showed the strongest pathogenicity, while Fusarium solani and Alternaria tenuis were weak, Rhabditis elegans was non pathogenic. With the three formers as inocula, the root rot rates of mixed inoculations were all higher than that of their individual inoculations. The combined inoculation of the three pathogens showed the highest pathogenicity. With new multiple range test, root rot rates among 3 combined inoculations and their individual inoculation resulted in significant diffenence (P=0.05). The present experiments reveals the fact that the bacteria played an important role in the combination infection with other fungous and nematode pathogens.