Screening rhizosphere growth-promoting bacteria from Schisandra chinensis. (English)

[Objective] This study screened rhizosphere-promoting bacteria with multiple growth-promoting functions from rhizosphere soil of Schisandra chinensis and explored the growth-promoting effects on S. chinensis seedlings to provide excellent bacterial resources for the development of microbial fertilizers. [Method] Cultivable bacteria were isolated and purified from rhizosphere soil of S. chinensis using the plate streaking method, and their abilities to fix nitrogen, deconvolve organic phosphorus, dissolve inorganic phosphorus and produce indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase were measured to screen strains with multiple growth-promoting functions.The screened strain was identified by constructing a phylogenetic tree based on 16S rRNA gene sequence, and its growth-promoting effect on S. chinensis seedlings was explored by pot experiment. [Result] A total of 85 bacteria were isolated from rhizosphere soil of S. chinensis.By measuring their abilities to fix nitrogen, deconvolve organic phosphorus, dissolve inorganic phosphorus and produce indole acetic acid, siderophore and ACC deaminase, strain 142 with strong comprehensive growth-promoting ability was identified.Its nitrogen fixation ability value was 1.56, organic phosphorus deconvolution ability value was 2.06, inorganic phosphorus dissolution ability value was 1.47, indole acetic acid mass concentration was 52.34 mg/L, siderophore expression amount was 49.65%, and ACC deaminase activity was 0.22.Strain 142 was identified as Serratia fonticola and pot experiment results showed that it could promote the growth of S. chinensis seedlings.After applying the strain, plant height was increased by 198.20%, stem thickness was increased by 53.05%, fresh weights of aboveground and belowground were increased by 92.95% and 73.95%, and dry weights of aboveground and belowground were increased by 111.76% and 98.33%, chlorophyll a and b content increased by 42.00% and 8.11%. [Conclusion] The screened growth-promoting bacterium S. fonticola 142 had evidently promoting effect on the growth of S. chinensis seedlings. [ABSTRACT FROM AUTHOR]

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