金丝小枣浆烂果病症状、危害及病原菌鉴定

金丝小枣浆烂果病严重危害我国北方枣树，并且逐年加重。本研究通过室内分离培养与田间调查，经多年多地试验，查明此病的症状、危害及病原菌。结果显示：金丝小枣浆烂果病在河北、山东、天津的产区普遍发生，以河北泊头市发病最重。该病在枣果进入白熟期(8月20日左右)开始发病，形成侵染点明显的红色近圆形软腐病斑。1998—2000年3年平均发病率和病情指数分别为36．7％和26．9。依据柯赫氏法则对金丝小枣浆烂果病病原菌进行了研究，根据病原菌形态特征，病原菌有性阶段鉴定为囊孢壳菌(Physalospora obtuse，(Schw．))，无性世代鉴定为梭壳孢菌(Fusicoccum sp．)。经黑光灯诱导后，囊孢壳菌在室内PDA培养基上可形成子座与分生孢子器。有性世代的子囊壳与子囊孢子只发现于越冬后的病枣果中。

Study on the symptom,harm and pathogen identification of thick rotten disease of Ziziphus jujuba Mill.cv.Jinsixiaozao

The thick rotten disease of Ziziphus jujuba Mill. cv. Jinsixiaozao has been studied in the laboratory and field in many years. The study results are as follows: The thick rotten disease of Z. jujuba Mill. cv. Jinsixiaozao generally occurred in the production areas in Hebei province, Shandong province and Tianjin. It was most serious in Botou county, Hebei province. The thick rotten disease occur on the fruit in August 20, while the fruit become red and disciform thick rotten spot. The pathogens is Physalospora obtuse (Schw.), and the agamobium is Fusicoccum sp.