新疆南疆桃树腐烂病菌生物学特性研究

Biological Characteristics and Pathogenicity of Valsa Canker Pathogen of Peach Tree in Southern Xinjiang

【目的】对引起南疆桃树腐烂病菌的无性形态和培养性状观察、致病性的测定,明确病原菌主要生物学特性,为该病的防治提供理论依据。【方法】采用徒手切片技术,观察测量分生孢子器大小、腔室数量、分生孢子形状和大小;将桃树腐烂病菌分别接种于桃树、梨树、苹果树、枣树、杨树、柳树、胡杨树的枝条上,观察发病情况,测定其致病性及寄主范围;将病原菌接种于PDA培养基上,置于不同温度、p H值、光照、碳氮源条件下,观察记录培养性状。【结果】病菌分生孢子器具有10~15个腔室,分生孢子腊肠形;病原菌均能成功侵染7种树木,在桃树、苹果树、梨树寄主上病斑扩展速率和形成产孢体较快;病原菌在5~35℃均能生长,在p H 1~9菌丝生长存在差异性,光照条件对菌落生长速率、形成产孢体速率和数量之间存在显著差异性。【结论】根据无性形态特征鉴定病原菌为桃幹枯蕉孢菌(C.leucostma Sace.)。病原菌能使7种不同寄主感病,但在病斑扩展速度和形成产孢体能力方面存在明显差异。病原菌生长最适温度为20~25℃,最适p H值5~6,在全光照条件下菌落生长最好,形成产孢体最快且数量最多;病原菌生长的最佳碳源是淀粉,最佳氮源是酵母膏。

【Objective】The purpose of this study is to specify the main biology characteristics of pathogenic bacteria and provide theoretical basis for disease control through the observation of vegetative form and culture characters and the determination of pathogenic of peach trees ' rot pathogen in Southern Xinjiang.【Method】Firstly,observing the size of conidium device,the number of chamber,and the shape through unarmed slice technology; Secondly,inoculating the peach trees' rot pathogen in the branches of peach trees,pear trees,apple trees,jujube trees,poplars,willows,and populus to observe the incidence of the trees and measure its pathogenicity and host range. Thirdly,the pathogen was inoculated in the PDA medium and then put under different conditions of temperatures,p H,lights,carbon and nitrogen sources to observe and record cultivate characters.【Result】The conidium had 10- 15 chambers,which looked like sausages. Pathogenic bacteria could infect 7 kinds of trees successfully. On the peach trees,pear trees and apple trees,the disease spots expanded rapidly and formed spores quickly. Pathogenic bacteria could grow under 5- 35℃ 。But mycelia difference existed in the range of p H 1- 9. The colony growth rate,the sproes production and amounts were different under different conditions of temperature.【Conclusion】The pathogenic bacteria were identified as C. leucostma Sace according to the colonel morphology characteristics. And they could infect 7 kinds of disease spots extension and the ability of spores production displayed significant difference. The most suitable temperature for the growth of pathogenic bacterias was 20- 25℃,and the PH was 5- 6. Under the complete illumination,bacterial colony grew fastest and quickly produced the largest amount of spores. The best carbon source for the pathogenic bacteria's growth was starch,and the best nitrogen source was yeast extract.