解淀粉芽胞杆菌PHODB35的溶磷特性及其对番茄的促生作用

Phosphate-solubilizing characteristics of Bacillus amyloliquefaciens PHODB35 and its growth-promoting effect on tomato

摘要:

[目的] 从种植番茄的根围土壤中筛选高效溶磷细菌，为减施化学肥料和开发微生物肥料提供溶磷菌种资源，并初步探索其促生机制。[方法] 采用无机磷培养基利用梯度稀释涂布法从土壤中分离筛选促生菌株，通过形态特征、16S rRNA和gyrB基因序列分析对优良促生菌株进行鉴定，并分别利用正交试验和单因素试验分析环境因子和营养因子对其溶磷效果的影响，进一步利用HPLC-MS并结合相应有机酸的标准物质，明确优良促生菌株产生的有机酸种类；盆栽试验测定接菌处理后番茄株高、地上鲜重、地下鲜重、基质和植株有效磷含量评价菌株对番茄的促生作用。[结果] 筛选到1株优良的促生菌株，命名为PHODB35，鉴定其为解淀粉芽胞杆菌（Bacillus amyloliquefaciens）。对环境因子的正交试验结果表明，菌株PHODB35最佳溶磷条件为pH 7.0，温度为30℃，接种量为5%；对营养因子的单因素试验结果表明，该菌株以葡萄糖为碳源、硫酸铵为氮源、磷酸钙为磷源时，解磷效果最好，有效磷浓度为88.77 mg/L。明确了菌株PHODB35产生的有机酸为葡萄糖酸。盆栽实验结果表明，菌株PHODB35对番茄幼苗有明显的促生作用，与空白对照相比，施用菌株后对株高、地上鲜重、地下鲜重、基质和植株有效磷含量分别增加28.21%、22.59%、113.06%、45.08%和16.24%，表明菌株PHODB35具有一定的肥效功能，可用于促生菌剂的研制。[结论] 筛选到具有促生能力的解磷细菌，为进一步开发研制番茄促生菌剂或微生物有机肥提供资源，为菌株PHODB35在农业生产中的应用提供了理论依据和实验基础。

关键词:解淀粉芽胞杆菌;溶磷特性;有机酸;促生作用;番茄

Abstract:

[Objective] Phosphorus-soluble bacteria were screened from the soil around the roots of tomato plants to provide phosphorus-soluble bacteria resources for the development of biofertilizers for increasing production and saving fertilizer, and their growth-promoting mechanism was preliminarily explored. [Methods] Inorganic phosphorus medium was used to isolate and screen the growth-promoting strains from soil by serial dilution plating method. The excellent growth-promoting strains were identified by morphological characteristics, 16S rRNA gene sequence and gyrB gene sequence analysis, and the effects of environmental factors and nutrient factors on phosphorus solubility were studied by orthogonal and single factor test. Organic acids produced by excellent growth-promoting strains were identified by HPLC-MS, according to the standard substances of corresponding organic acids, and the growth-promoting effect of strains on tomato was determined by pot experiment. [Results] A good growth-promoting strain named PHODB35 was isolated. It was identified as Bacillus amyloliquefaciens. The orthogonal test of environmental factors shows that the optimum conditions for dissolving phosphorus of strain PHODB35 were pH 7.0, temperature at 30℃ and 5% inoculation. The results of single-factor experiments on nutrient factors show that strain PHODB35 had the best phosphorus dissolution effect with glucose as carbon source, ammonium sulfate as nitrogen source, calcium phosphate as phosphorous source, initial pH 7.0 and temperature at 30℃. The effective phosphorus concentration was 88.77 mg/L. Gluconic acid was produced by strain PHODB35. Pot experiment showed that the application of strain PHODB35 had obvious growth-promoting effect on tomato seedlings. Compared with the control, the plant height, above-ground fresh weight, under-ground fresh weight, substrate and plant available phosphorus content were increased by 28.21%, 22.59%, 113.06%, 45.08% and 16.24%, respectively, after inoculating strain PHODB35, indicating that strain PHODB35 had certain fertilizer effect and could be used for the development of growth-promoting agents. [Conclusion] Phosphorus solubilizing bacteria were screened to provide resources for further development of tomato specific growth-promoting agent or special microbial organic fertilizer, and to provide theoretical and experimental basis for the application of strain PHODB35 in agricultural production.

Key words:Bacillus amyloliquefaciens;phosphate-solubilizing characteristics;organic acid;growth-promoting effects;tomato