栀子炭疽病病原菌鉴定及抑菌药剂筛选

目的:明确引起栀子炭疽病病原菌种类,研究常用杀菌剂对病原菌菌丝生长的抑制作用,为病害防治提供依据。方法:采集江西省不同地区栀子炭疽病病叶标本,采用常规组织分离法进行病原菌的分离与纯化,基于柯赫氏法则,检测病原菌的致病性,采用形态观察、显微鉴定、真菌r DNA-ITS序列分析,系统的鉴定病原菌,选取常用的11种抑菌剂对其进行室内药剂毒力测定,并建立抑制率与药剂浓度的相关回归方程;筛选出有明显抑菌作用的药剂,为防治该病的发生提供理论依据。结果:从收集的栀子炭疽病病原菌感染的叶片中分离纯化得到11个菌株,经致病性测定和科赫氏验证确定使栀子发病快且病情严重的菌株,通过形态和显微鉴定并对扩增得到的r DNA-ITS序列进行Blast对比分析,确定该病害为茎点霉菌Phoma.sp。选用的药剂中武夷菌素、链霉素和寡糖链蛋白无明显的抑菌效果,多菌灵的抑菌效果最好,回归方程为Y=79.97X-1.75[r=0.965,半最大效应浓度(EC_(50))=0.65 mg·L~(-1)],其次为咪鲜三环唑和五硝多菌灵,回归方程分别为Y=6.142X+19.47(r=0.902,EC50=4.97 mg·L~(-1)),Y=6.1X+17.23(r=0.93,EC_(50)=5.37 mg·L~(-1)),其他药剂呈现不同程度的抑菌效果。结论:确定了栀子炭疽病病原菌并筛选出了抑制病原菌的有效药剂。

Identification of Gardenia jasminoides Anthracnose Pathogen and Screening of Its Antibiotics Agents

Objective: To define the type of fungi causing Gardenia jasminoides pathogenic anthracnose, and study the inhibitory effect of commonly antisepticson the mycelial growth of the pathogens, in order to provide a basis for preventing and treating the disease. Method: G.jasminoides anthracnose leaves were collected from several regions of Jiangxi province. The pathogens were isolated and purified by general tissue separation. According to the Koch''s postulates, pathogenicity test, pathogen morphological observation, microscopic identification and rDNA-ITS sequence analysis were used to identify the pathogens. Eleven fungicides were selected to test their indoor sterilizing effect. Thetoxicity regression equationfor agent concentration and inhibition ratio was established, and the effective fungicides were screened out, in a bid to provide a theoretical basis for controlling the disease. Result: Eleven strains were separated from G.jasminoides anthracnose leaves. Through pathogenic determination and Koch''s Postulates, one strain was confirmed to be the main pathogen that attacks G.jasminoides quickly and severely. On the basis of morphology and microscopic identification, and Blast comparison analysis for rDNA-ITS sequences, the pathogenic strain was identified to be Phoma.sp. The fungicides Wuyiencin, streptomycin and oligosaccharide chain protein had no significant inhibition effect,but carbendazol showed the best sterilizing effect,whose regression equation was Y=79.97X-1.75 (r=0.965, EC₅₀=0.65 mg·L^-1). The next were prochloraz tricyclazole and pentanitro-carbendazim, whose regression equations were Y=6.142X+19.47(r=0.902, EC₅₀=4.97 mg·L^-1) and Y=6.1X+17.23(r=0.93, EC₅₀=5.37 mg·L^-1), respectively. The others showed varying inhibition effect. Conclusion: The G. jasminoides anthrax pathogen was determined, and effective agents to inhibit pathogens were screened out.