赭红枝顶孢Acremonium salmoneum对竹叶锈病菌的重寄生作用研究

Mycoparasitic Activities of Acremonium salmoneum against Bamboo Leaf Rust

竹叶锈病(Puccinia spp.)是竹类主要病害之一,影响竹林生长。为了利用重寄生菌赭红枝顶孢Acremonium salmoneum防治竹叶锈病,本文研究了该重寄生菌的寄生规律及其抑病作用。结果表明,该重寄生菌的分生孢子自然条件下可在锈病病斑上越冬,作为次年重寄生的初侵染源;分生孢子主要依靠风吹雨溅在林间传播,可发生多次再侵染;林间温度在16.4～25.4℃下,潜育期为10～18d;采用纸环法观察重寄生菌对锈病菌(Puccinia longicornis和P.phyllostachydis)夏孢子的萌发情况可知,重寄生菌对锈病菌夏孢子的萌发有较强的抑制作用,24h后2种锈菌夏孢子的萌发率均很低,分别仅为11.1%和8.7%,同时该重寄生菌可抑制锈病病斑的扩展。竹叶锈病重寄生发生与环境条件有密切关系,在竹林较密、经营管理较差的林分竹叶锈病重寄生率明显较高。

Bamboo leaf rust diseases caused by Puccinia spp., affect the growth of bamboo severely. In order to control the disease with hyperparasite Acremonium salmoneum, authors investigated the occurrence and control efficiency of the hyperparasite. Results showed that conidia of the hyperparasite overwintered on the rusted leaves under natural condition, and served as primary infection source for next year. The conidia were disseminated by airflow and rain and could cause several infections. The incubation period was 10-- 18 days at 16.4--25.4 ~C. Paper ring test demonstrated that A. salmoneum strongly inhibited germination of urediospores germination of Puccinia longicornis and P. phyllostachydis, with germination rates of 11.1% and 8.7% respectively after 24 h; and also could inhibit the lesion expansion of rust. Hyperparasitism occurrence of bamboo leaf rust was closely related to the environmental conditions, and the hyperparasite rate was higher in dense and poor-managed bamboo forest.