石漠化地区核桃根腐病病原菌分离及拮抗菌筛选鉴定

Isolation of Walnut Root Rot Pathogenic Bacteria and Screening and Identification of Antagonistic Bacteria in Rocky Desertification Area

从河池市石漠化地区采集发病的核桃树根部,采用常规组织分离法分离致病菌,并从健康核桃根部土壤中用平板对峙法及混菌平板法筛选拮抗菌,然后根据菌落形态、形态学特性结合分子生物学方法进行鉴定。结果表明:从发病部位筛选到1株致病菌ML-1,经回染试验证实为根腐病病原菌;从土壤中筛选到1株对此病原菌有拮抗作用的拮抗菌ML-11,拮抗作用明显;利用形态学及分子生物学方法鉴定ML-1为木贼镰刀菌,ML-11为枯草芽孢杆菌。

The roots of diseased walnut trees were collected from rocky desertification area in Hechi City,and the pathogenic bacteria were isolated by conventional tissue isolation method,antagonistic bacteria were screened from healthy walnut root soil by plate confrontation method and mixed plate method.They were identified according to colony morphology,morphological characteristics and molecular biology methods.The results showed that a pathogenic bacterium ML-1 was screened from the diseased site and proved to be the root rot pathogen by the reinfection test;one antagonistic strain ML-11 was screened from soil,which had obvious antagonistic effect against the pathogen;ML-1 was identified as Fusarium equisetum and ML-11 was identified as Bacillus subtilis by morphological and molecular biological methods.