摘要：

为探究不同解磷细菌组合接种的解磷效果及其对玉米生长和磷素吸收的影响,以3株分类地位和解磷能力均存在差异的菌株-弗雷德里克斯堡假单胞菌P4-5、水稻节杆菌P5-41和阿氏芽孢杆菌P3-50为研究对象,以不接种处理为空白对照(CK),设置单接种P4-5(Pf)、单接种P5-41(Ao)、单接种P3-50(Ba)、双接种P4-5和P5-41(Pf×Ao)、双接种P4-5和P3-50(Pf×Ba)、双接种P5-41和P3-50(Ao×Ba)、组合接种P4-5、P5-41和P3-50(Pf×Ao×Ba)处理,利用盆栽试验分析不同接种处理对玉米根系形态、地上部生长、磷素吸收及菌株吲哚乙酸(IAA)分泌能力的影响。结果表明,与CK相比,接种解磷细菌均可显著提高玉米茎粗、叶片SPAD值、地上部生物量、吸磷量,同时也显著激活了根际碱性磷酸酶活性(单接种Pf和Ba处理除外),降低了土壤有效磷含量(单接种Ba处理除外)。其中,组合接种Pf×Ao×Ba处理整体表现最优,能够分泌高浓度的IAA,优化玉米根系形态(增加根长、体积、表面积及根尖数),还能显著提高根际碱性磷酸酶活性,促进土壤有机磷矿化,进而高效促进玉米生长和磷素吸收。综上,复合接种Pf×Ao×Ba处理可通过分泌IAA优化玉米根系形态(增加根系长度、体积、表面积及根尖数),提升碱性磷酸酶活性有效活化土壤有机磷的双重机制,显著促进玉米生长并改善磷营养状况。

关键词: 玉米, 解磷细菌, 组合接种, 根系形态, 碱性磷酸酶活性, 磷素吸收

Abstract:

To investigate the phosphate-solubilizing effects of different combinations of phosphate-solubilizing bacteria(PSB)and their impact on maize growth and phosphorus uptake,a pot experiment was conducted using three bacterial strains with distinct taxonomic classifications and phosphate-solubilizing capacities:Pseudomonas frederiksbergensis P4-5,Arthrobacter oryzae P5-41,and Bacillus aryabhattai P3-50.A non-inoculated treatment served as the blank control(CK),and the experimental treatments included:single inoculation with P4-5(Pf),single inoculation with P5-41(Ao),single inoculation with P3-50(Ba),dual inoculation with P4-5 and P5-41(Pf×Ao),dual inoculation with P4-5 and P3-50(Pf×Ba),dual inoculation with P5-41 and P3-50(Ao×Ba),and combined inoculation with P4-5,P5-41,and P3-50(Pf×Ao×Ba).The effects of these inoculation treatments on maize root morphology,shoot growth,phosphorus uptake,and indole-3-acetic acid(IAA)secretion capacity by the bacterial strains were analyzed.The results indicated that,compared to the CK,all PSB inoculations significantly increased maize stem diameter,leaf SPAD value,shoot biomass,and phosphorus uptake.Furthermore,they also significantly enhanced rhizosphere alkaline phosphatase activity(except for single inoculation with Pf and Ba,respectively)and reduced soil available phosphorus content(except for single inoculation with Ba).Among these treatments,the combined inoculation of Pf×Ao×Ba exhibited the best overall performance.This treatment secreted high concentrations of IAA,optimized maize root morphology(increasing root length,volume,surface area,and number of root tips),and significantly increased rhizosphere alkaline phosphatase activity,thereby promoting the mineralization of soil organic phosphorus and consequently enhancing maize growth and phosphorus uptake.In conclusion,the combined inoculation of Pf×Ao×Ba significantly promoted maize growth and improved phosphorus nutrition through a dual mechanism:optimizing root morphology by increasing root length,volume,surface area,and root tip number through IAA secretion,and effectively mineralizing soil organic phosphorus by enhancing alkaline phosphatase activity.

Key words: Maize, Phosphate-solubilizing bacteria(PSB), Combined inoculation, Root morphology, Alkaline phosphatase activity, Phosphate uptake

中图分类号: 

• S513玉米(玉蜀黍)

• S154.3