促植物生长根际细菌HG28-5对黄瓜苗期生长及根际土壤微生态的影响

Effects of Plant Growth Promoting Rhizobacteria HG28-5 on Cucumber Seedling Growth and Rhizosphere Microecology

为研究促植物生长根际细菌HG28-5对黄瓜生长发育和根际土壤微生态的影响,采用HG28-5菌悬液进行黄瓜浸种处理后播种到穴盘,调查出苗和苗期生育指标,确认其对黄瓜的促生作用;测定黄瓜苗期根际土壤酶活性、速效氮磷钾和微生物种群数量,了解HG28-5对黄瓜苗期根际土壤微生态的影响;并检测HG28-5在黄瓜苗期植株根部和根际土壤的定殖密度。结果表明,HG28-5浸种处理能显著提高黄瓜的出苗势、出苗指数,提高出苗整齐度;显著增加苗期黄瓜株高、叶片数、根长、地上部和根鲜质量,显著提高根系活力;显著提高黄瓜苗期根际土壤脲酶、磷酸酶和蔗糖酶的活性,显著增加根际土壤速效磷的含量;显著增加黄瓜苗期根际土壤细菌和放线菌的数量,显著减少根际土壤真菌数量;另外,HG28-5在黄瓜根际具有良好的定殖能力,播种后第30天时,在黄瓜根系和根际土壤中的定殖密度分别为9.20×10~5cfu·g^(-1)和5.90×10~5cfu·g^(-1)。

In order to study the effects of plant growth promoting rhizobacteria HG28-5 on cucumber growthand its rhizosphere microecology,this experiment sowed the cucumber seeds in trays after soaking them in HG28-5 suspension.Then the quotas of emerging and seedling growth were examined to confirm its promotion effectson cucumber growth.The enzymatic activities in rhizosphere soil,available N,P,K and microbial populationwere measured to comprehend the effects of HG28-5 on cucumber rhizosphere soil microecology,and to check thecolonization densities of HG28-5 in cucumber root and its rhizosphere soil in seedling stage.The results showedthat soaking seed in HG28-5 treatment could remarkably increase seedling emergence potential,germination indexand improve germination uniformity of cucumber.The soaking treatment with HG28-5 could also remarkablyincrease the plant height,numbers of leaves,root length,shoot fresh weight and root fresh weight of cucumberduring its seedling stage,and significantly improve cucumber root system activity.The soaking treatment withHG28-5 could remarkably improve urease,phosphatase and sucrase activities in cucumber rhizosphere soil,increasethe available P content,the amount of bacteria and antinomycetes,While decreaseing the rhizosphere soilfungi quantity during its seeding stage.Besides,HG28-5 could colonize well in cucumber rhizophere.Thirtydays after sowing,HG28-5 could maintain a density of 9.20×10^5 cfu · g^-1 and 5.90×10^5 cfu·g^-1,respectivelyin cucumber root and its rhizosphere soil.