Background Deterioration of the ecological environment in recent years has led to increasing soil salinization, which severely affects the cultivation of agricultural crops. While research has focused on improving soil environment through the application of pollution-free microbial fertilizers, there are relatively few plant growth-promoting bacteria suitable for saline-alkali environments. Although Klebsiella variicola can adapt to saline-alkali environments to successfully colonize rhizosphere microenvironments, only a few studies have investigated its role in promoting crop growth. Its effect on the crop rhizosphere soil microenvironment is especially unclear. Methods In this study, the biological function of K. variicola and its colonization in maize seedling rhizosphere soil were studied in detail through selective media and ultraviolet spectrophotometry. The effects of K. variicola on the rhizosphere soil microenvironment and the growth of maize seedlings in saline-alkali and neutral soils were systematically analysed using the colorimetric method, the potassium dichromate volumetric method, and the diffusion absorption method. Results Our results showed that K. variicola played a role in indole acetic acid, acetoin, ammonia, phosphorus, and potassium production, as well as in nitrogen fixation. A high level of colonization was observed in the rhizosphere soil of maize seedlings. Following the application of K. variicola in neutral and saline-alkali soils, the nutrient composition of rhizosphere soil of maize seedlings increased in varying degrees, more notably in saline-alkali soil. The content of organic matter, alkali-hydrolysable nitrogen, available phosphorus, available potassium, alkaline phosphatase, sucrase, urease, and catalase increased by 64.22%, 117.39%, 175.64%, 28.63%, 146.08%, 76.77%, 86.60%, and 45.29%, respectively, insaline-alkalisoil. Conclusion K.variicola, therefore, performed a variety of biological functions to promote the growth of maize seedlings and effectively improve the level of soil nutrients and enzymes in the rhizosphere of maize seedlings, undersaline-alkali stress conditions. It played an important role in enhancing the rhizosphere microenvironment of maize seedlings under saline-alkali stress.

中文翻译：

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水痘克雷伯菌的生物学功能及其对玉米幼苗根际土壤的影响


背景技术近年来，生态环境恶化，土壤盐碱化现象日益严重，严重影响农作物的种植。虽然研究主要集中在通过施用无污染的微生物肥料来改善土壤环境，但适合盐碱环境的植物促生细菌相对较少。尽管水痘克雷伯氏菌可以适应盐碱环境并成功定植根际微环境，但只有少数研究探讨其促进作物生长的作用。其对作物根际土壤微环境的影响尤其不清楚。方法本研究通过选择性培养基和紫外分光光度法详细研究了水痘克氏菌的生物学功能及其在玉米幼苗根际土壤中的定殖情况。采用比色法、重铬酸钾容量法和扩散吸收法，系统分析了水花堇菜对根际土壤微环境以及盐碱和中性土壤中玉米幼苗生长的影响。结果我们的结果表明，K. variicola 在吲哚乙酸、乙偶姻、氨、磷和钾的生产以及固氮中发挥作用。在玉米幼苗的根际土壤中观察到高水平的定殖。在中性和盐碱土壤中施用水花玉米后，玉米幼苗根际土壤的养分成分都有不同程度的增加，其中以盐碱土壤最为显着。有机质、碱解氮、速效磷、速效钾、碱性磷酸酶、蔗糖酶、脲酶、过氧化氢酶含量增加64.22%，117。盐碱土分别为 39%、175.64%、28.63%、146.08%、76.77%、86.60% 和 45.29%。结论 水花岬在盐碱胁迫条件下发挥多种生物学功能，促进玉米幼苗生长，有效提高玉米幼苗根际土壤养分和酶水平。对改善盐碱胁迫下玉米幼苗根际微环境具有重要作用。