假单胞菌T1-3-2的抑菌特性及其对杉木的抗病促生作用

【背景】生物防治是“基于自然的解决方案”，有利于生态文明和可持续发展，开展生物防治技术研究的基础是明确菌株的生防作用和抑菌特性。【目的】探究杉木内生菌株T1-3-2的抑菌促生特性，为研制该菌株生防菌剂、防治杉木炭疽病(Cunninghamia lanceolata anthracnose)奠定基础。【方法】通过形态学特征、生理生化特性及16S rRNA基因序列分析，确定菌株T1-3-2的分类地位；通过平板对峙、菌落径向生长抑制率和平板倒扣等方法测定细菌及其挥发性气体和次级代谢产物的抑菌作用；同时，测定其促生作用和室内防效。【结果】菌株T1-3-2与桉生假单胞菌(Pseudomonas eucalypticola)亲缘性较近，属于假单胞菌属。该菌株对分属于6个属的10株靶标菌株具有较强的拮抗作用，尤其对炭疽菌属、拟盘多毛孢属、黑孢霉属和葡萄座腔菌属的6株靶标菌株抑制率高达80%以上。室内盆栽试验显示：菌株T1-3-2用Kings Medium B液体培养基的发酵菌液对杉木炭疽病的防效可达74.20%，同时能有效改善杉木幼苗的生长状况、增加生物量。【结论】菌株T1-3-2隶属于假单胞菌属，对杉木具有良好的抗病促生作用，是一株具有开发潜力的生防菌株。

Pseudomonas sp. T1-3-2 with antimicrobial activities improves the disease resistance and promotes the growth of Cunninghamia lanceolata

[Background] Biocontrol is a nature-based solution that meets the requirements of ecological civilization and sustainable development. Clarifying the biocontrol effects and antibacterial characteristics of the bacterial strain are the basis of biocontrol of technology research. [Objective] To develop biocontrol agent for the control of anthracnose in Cunninghamia lanceolata, we studied the antimicrobial activity and growth-promoting effect of strain T1-3-2 isolated from C. lanceolata. [Methods] Strain T1-3-2 was identified based on morphological, physiological and biochemical characteristics, and the 16S rRNA gene sequence-based phylogenetic analysis. The antimicrobial effects of the bacterial strain, volatile gas and secondary metabolites of the strain were determined by plate confrontation method, plate culture method, and colony growth inhibition test. The plant growth-promoting effect of the strain was determined by pot experiment indoors. [Results] Strain T1-3-2 belongs to Pseudomonas, forming a monophyletic group with Pseudomonas eucalypticola. It had stronger antagonistic effects on 10 target strains, with the inhibition rates over 80% on 6 strains of Colletotrichum, Pestalotiopsis, Nigrospora, and Botryosphaeria. The pot experiments showed the fermentation broth of T1-3-2 in Kings Medium B controlled the occurrence of anthracnose in C. lanceolata, with the control effect of 74.20%. Moreover, it improved the growth and increased the biomass accumulation of C. lanceolata seedlings. [Conclusion] Strain T1-3-2 is belonging to the Pseudomonas genus and it is beneficial to the biocontrol and growth-promoting on C. lanceolata. Thus, it is a great potential biocontrol strain.