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[目的]探讨棉花不同生育期的生防菌组合防治棉花黄萎病效果,以期为植物其他土传病害的生物防治提供新的策略。[方法]分别筛选棉花苗期、现蕾期和结铃期的高抗黄萎病内生菌,测定其16SrDNA序列并进行比对分析,鉴定筛选出的3个菌株,探讨了该3个菌株在棉株内的定殖规律,并进行室内和田间防效测定。[结果]根据16SrDNA序列同源性,3个菌株分别鉴定为PaenibacilluspolymyxaYUPP-8、Paenibacillusxy-lanilyticusYUPP-1和BacillussubtilisYUPP-2。定殖评价试验结果显示3个菌株均能顺利定殖于棉花体内,施用剂量与其在棉株内的定殖量具有正效应关系,在棉花苗期定殖量最高的菌株为YUPP-8,在棉花现蕾期定殖量最高的菌株为YUPP-1,在棉花结铃期定殖量最高的菌株为YUPP-2。室内盆栽抗病结果显示3个菌株联合处理的棉株在开花期未发病,单菌处理的棉株在苗期发病率分别为:6.7%(YUPP-8)、6.7%(YUPP-1)和13.3%(YUPP-2);而此时对照的发病率高达80%。2010～2011年2年的小区防治试验结果表明3菌联合灌根处理效果优于单菌株施用效果,其中,2010年3菌联合灌根处理区棉花结铃期黄萎病发病率和病指分别为9.4%和6.5,对照分别为47.5%和32.8,2011年的结果趋势与2010年类似,但病害严重度更高一些。上述结果表明联合棉花各生育期的内生菌来防治棉花黄萎病具有巨大的应用潜力。[结论]该研究结果初步克服了目前生防菌开发中的缺陷,对其他植物土传病害的防治具有借鉴意义。
[Objective] The research aimed to explore the effects of biocontrol and combination of biocontrol bacteria in preventing and controlling cotton verticillium wilt at different growth stages in order to provide a new strategy for the biological control of other soil-borne diseases of plants. [Method] Endophytic fungus with high resistance to Verticillium dahliae were selected at seedling stage, budding stage and boll stage respectively. The 16SrDNA sequences were determined and compared with each other. The three selected strains were identified. The three strains Colonization within the cotton plant law, and indoor and field control efficacy test. [Result] According to 16S rDNA sequence homology, three strains were identified as PaenibacilluspolymyxaYUPP-8, Paenibacillusxy-lanilyticusYUPP-1 and BacillussubtilisYUPP-2 respectively. The results of colonization evaluation showed that all three strains could successfully colonize in cotton. The application dose had a positive effect on its colonization in cotton plants. The strain with the highest colonization rate in cotton seedlings was YUPP-8. The highest colonization rate of cotton was YUPP-1 at budding stage and YUPP-2 was the highest colonization rate at cotton boll stage. The resistance results of in-house pot plants showed that the three strains were not infected at flowering stage. The single-strain cotton plants were 6.7% (YUPP-8), 6.7% (YUPP-1) 13.3% (YUPP-2), while the incidence of controls was as high as 80%. The results of community control experiments from 2010 to 2011 showed that the combined effect of 3 fungi and irrigation was better than that of single fungus. In 2010, the morbidity and disease index of Verticillium wilt Were 9.4% and 6.5, respectively, with controls of 47.5% and 32.8 respectively. The trend in 2011 was similar to that in 2010, but the disease was more severe. The above results show that the combination of endophytes in cotton growth stages to prevent and control cotton Verticillium wilt has great potential. [Conclusion] The results of this study have basically overcome the defects in the development of biocontrol microbes and have reference significance for the prevention and treatment of soil-borne diseases of other plants.