石榴叶斑病球毛壳菌生长习性及杀菌剂筛选

Growth characteristics of mycelia of Chaetomium globusum causing pomegranate leaf spot disease and fungicides screening

采用生长速率法研究了云南蒙自石榴叶斑病球毛壳菌菌丝生长的条件及有效杀菌剂。结果表明,球毛壳菌菌丝在26~34℃均能生长,适宜温度是26~32℃,最适温度为28℃;偏好75%~85%的相对湿度,最适相对湿度为85%;光照促进菌丝生长;pH值4.5~7.5时均适宜于球毛壳Bd-2菌丝的生长,最适pH值为6.5,表明该菌偏好弱酸性环境。不同碳源、氮源对球毛壳菌菌丝生长的影响均较明显,麦芽糖和蛋白胨对菌丝生长有显著的促进作用。随后,分别用75%百菌清、80%甲基硫菌灵和80%代森锰锌等3种常见杀菌剂,以及细辛、小桐子和夹竹桃等3种植物提取液在培养基上进行抑菌实验,从菌丝生长的抑制率大小初步鉴定80%甲基硫菌灵为该病害的有效杀菌剂;在3种植物提取液中,细辛提取液对球毛壳Bd-2的菌丝生长抑制率最高,4 mg·mL^(-1)抑菌率达100%。明确了云南蒙自石榴叶斑病球毛壳菌生长的环境条件及有效杀菌剂,为生产上化学防治提供了选择杀菌剂的理论基础。

Biological characteristics and effective fungicide of Chaetomium globosum Kunze causing leaf spot disease on pomegranate were studied using mycelia growth rate method. The results showed that the mycelia of C. globosum could grow under the temperature of 26-34℃. The suitable temperature was between 26℃ and 32℃ and the most suitable temperature was 28℃. The scope of suitable humidity was 75%-85% and the most suitable humidity was 85%. Light promoted the mycelia growth. The mycelia of C. globosum could grow at pH4.5-7.5 and the optimal pH was 6.5. The effects of different carbon and nitrogen sources on mycelia growth were significant. Maltose and peptone obviously promoted the growth of mycelia. Furthermore, three fungicides including 75% chlorothalonil, 80% thiophanate-methyl and 80% mancozeb, as well as three plant extracts including Asarum sieboldii Miq., Jatropha curcas L. and Nerium indicum Mill., were used to test fungicide resistance of C. globosum. As a result, 80% thiophanate-methyl was identified as the most effective fungicide and 4 mg·mL^（-1） of A. sieboldii extract was the most effective compound for C. globosum control, which can provide some references for chemical control of C. globosum in practice.