新疆北部棉区黄萎病菌种群致病性分化及变异

采用特异性引物PCR检测技术和鉴别寄主法对新疆北部棉区41个棉花黄萎病菌菌系进行检测,以期明确黄萎病菌种群致病性分化及变异。特异性引物(ND1/ND2和D1/D2)PCR检测结果显示,供试菌系中落叶型菌系16个,占39.0%;非落叶型菌系24个,占58.5%;1个菌系未能检测出致病类型。鉴别寄主法测定结果显示:41个供试菌株中致病性强、中、弱的菌系分别为21、12和8个,分别占51.2%、29.3%和19.5%。落叶型菌系的致病力明显高于非落叶型,平均病情指数分别为39.4和25.8。研究表明,无论落叶型菌系和非落叶型菌系,接种后都可产生落叶症状,但落叶的程度有明显差别,其落叶症状的轻重不仅与菌系的致病类型有关,还与品种的抗病性密切相关。

The pathogenicity differentiation and variability of Verticillium dahliae from cotton in northern Xinjiang

To explore the pathogenicity differentiation and variability of Verticillium dahliae population from cotton in northern Xinjiang, 41 representative strains were collected and the pathogenicity type were determined on the basis of differential host tests and PCR assay. The results of special PCR primer (ND1/ND2 and D1/D2) assay showed that the defoliating and non-defoliating strains occupied 39.0% and 58.5% of total examined strains, respectively. The results of inoculating differential host tests showed that strong, medial and weak pathogenicity strains occupied 51.2%, 29.3% and 19.5% of total examined strains. Generally, the symptoms infected by the defoliating strains are more severe than non-defoliating strains, and the corresponding average index was 39.4 and 25.8. Defoliating symptoms have manifested in cottons infected by defoliating and non-defoliating strains. Thus, the defoliating symptom is not only related with the pathogenicity and pathotype of pathogens, but also with the resistance of cotton cultivars.