摘要 【目的】探究荧光假单胞菌菌株JW-JS1的溶磷能力及其在杨树根际和菌根际的定殖动态,揭示菌株的溶磷机制并进一步阐明溶磷细菌与外生菌根真菌的互作机制,为杨树专用复合菌剂的开发与应用提供理论依据。【方法】通过液体培养试验分析荧光假单胞菌菌株JW-JS1培养液可溶性磷含量、pH和可滴定酸含量的变化,采用高效液相色谱(HPLC)法测定有机酸种类和含量,利用抗利福平标记法筛选稳定的标记菌株,运用灌根法研究其在杨树根际和菌根际的定殖动态。【结果】1)JW-JS1菌株培养液可溶性磷含量随接种时间延长逐渐增加,培养液pH与可溶性磷含量呈极显著负相关(r=-0.889**),可滴定酸含量与可溶性磷含量呈极显著正相关(r=0.958**);2)JW-JS1菌株分泌的总有机酸量(434.39 mg·L-1)明显高于CK(25.94 mg·L-1)(P<0.05),共检测出草酸、酒石酸、柠檬酸、顺丁烯二酸和反丁烯二酸5种有机酸,其中,草酸含量(273.69 mg·L-1)明显高于其他种类有机酸,约占总有机酸量的63.01%;3)筛选出含有300μg·mL-1利福平抗性的标记菌株JW-JS1Rif,与原始菌株相比,其菌落形态和溶磷能力均未发生明显变化(P<0.05);4)标记菌株在杨树根际和菌根际均能长期稳定存活并保持一定的定殖数量,随接种时间延长定殖数量呈下降趋势,定殖动态基本一致,其中,接种50天后定殖数量分别为5.2×104和4.5×104cfu·g-1。【结论】荧光假单胞菌菌株JW-JS1的溶磷能力与培养液pH、可滴定酸含量和有机酸密切相关,特别是菌株分泌的草酸可能在溶磷过程中发挥重要作用。荧光假单胞菌菌株JW-JS1在杨树根际和菌根际均能长期稳定存活并保持一定的定殖数量。荧光假单胞菌菌株JW-JS1与红绒盖牛肝菌Xc是构建杨树专用功能复合微生物肥料的理想材料。 【Objective】This research aimed to explore the changes of phosphate-dissolving ability of Pseudomonas fluorescens at its strain JW-JS1 and the colonization dynamics in rhizosphere and mycorrhizosphere of poplars,to reveal the phosphate-dissolving mechanisms of this strain and further elucidate its interaction mechanisms with ectomycorrhizal fungi,so as to provide a theoretical basis for developing and exploiting the compound microbial fertilizer for poplar.【Method】A liquid fermentation experiment was conducted to investigate the changes of soluble phosphorus contents,pH,and titratable acid contents in the broth of P.fluorescens JW-JS1.Kinds and concentrations of organic acids in the broth were also determined by HPLC.The stable marker of antibiotic rifampin was screened by using the rifampin-resistant mutant method,and the colonizing dynamics of mutant strain in rhizosphere and mycorrhizosphere of poplars were investigated by root irrigating method.【Result】1)The results showed that the soluble phosphorus contents in broth of JW-JS1 gradually increased with the time.Correlation analysis showed that the pH was negatively correlated with soluble phosphorus contents(r=-0.889**),while the titratable acid contents was positively correlated with soluble phosphorus contents(r=0.958**).2)The total amounts of organic acid secreted by JW-JS1(434.39 mg·L-1)was significantly higher than that of control(25.94 mg·L-1)(P<0.05).Five kinds of organic acids were detected in the broth,including oxalic acid,tartaric acid,citric acid,maleic acid and fumaric acid.Among them,the amounts of oxalic acid(273.69 mg·L-1)was significantly higher than that of other kinds of organic acids,which was about 63.01%of the total organic acid concent.3)A strain of with 30μg·mL-1rifampicin resistance was selected.Compared with wild strain,there was no obvious change in colony morphology and phosphate-dissolving ability of JW-JS1Rif strain(P<0.05).4)The strain of JW-JS1Rif could effectively survive and maintain a certai
出处 《林业科学》 EI CAS CSCD 北大核心 2021年第3期90-97,共8页 Scientia Silvae Sinicae
基金 国家重点研发计划(2017YFD0600104) 江苏高校优势学科建设工程资助项目(PAPD) 国家自然科学基金项目(31400589)。
关键词 荧光假单胞菌 有机酸 草酸 杨树 菌根际 定殖 Pseudomonas fluorescens organic acid oxalic acid poplar mycorrhizosphere colonization
分类号 S718.7 [农业科学—林学]
