中文摘要：

为了解溶磷细菌促进作物生长的机制和最终效果，将不同剂量的溶磷细菌9320添加到土壤中，以此培养玉米幼苗，测量幼苗根系分泌物中的可溶性蛋白、可溶性糖、有机酸、土壤有效磷的含量、植株生长状况等．结果表明：随着土壤中溶磷细菌剂量的增加，玉米根系分泌物中可溶性蛋白含量增加，可溶性糖含量降低，有机酸种类和含量增加，根区土壤有效磷含量增加，根际土壤有效磷含量降低，玉米幼苗的株高、根长和质量都增加．同灭菌处理组相比，活菌处理组中，根系分泌物的蛋白含量和根区土壤有效磷含量更高，根系分泌物可溶性糖含量和根际土壤有效磷含量更低，玉米的生长情况更好．这些结果说明溶磷细菌能够将土壤中的难溶态磷转化为可溶态磷供植物吸收利用，而且能够促进根系的代谢活动，最终促进植物生长．

英文摘要：

To learn the mechanisms of growth promoting effect and final results of phosphate-solubilizing bacteria on crops, different dose of phosphate-solubilizing bacteria 9320 were applied to soil, onto which maize seedlings were cultivated. Sever- al indexes were measured, including the soluble protein and sugar, the organic acid in root secretion, the available phospho- rus content in soil, and the growth state of seedlings. The results showed that： with the increase of the dose of phosphate-sol- ubilizing bacteria in soil, the content of soluble protein, the kind and content of organic acid in secretion, and the available phosphorus in root-zone soil also increased, while the content of soluble sugar in secretion and the available phosphorus in rhizospheric soil decreased. As for the growth of maize seedlings, the seedlings height, the root length, and the weight all in- creased with the increase of the dose of phosphate-solubilizing bacteria. Compared with the treatment with inactive bacteria, the seedlings applied with active bacteria had more soluble protein, organic acid in secretion and available phosphorus in root-zone soil, and better growth state, as well as less soluble sugar and available phosphorus in rhizospheric soil. All these results demonstrated that phosphate-solubilizing bacteria 9320 not only can efficiently turn insoluble phosphorus into plant- available phosphorus in soil, but also can stimulate the metabolism in root, and finally enhance the growth of crops.