海螺沟冰川退缩区土壤溶磷型PGPR细菌的筛选及促生特性

Screening of soil cultivable phosphate-dissolving bacteria in Hailuogou glacier retreat area promoting plant growth

为探究海螺沟冰川退缩区土壤可培养溶磷细菌的促生特性,丰富溶磷微生物资源库,通过初筛和复筛从12株同时具有解无机磷和有机磷能力的菌株中得到高效解磷细菌;进行根际促生细菌(plant growth promoting rhizobacteria,PGPR)特性分析;对高效解磷细菌进行系统发育鉴定;菌株盆栽试验测定接菌处理后观察其对黄瓜的促生作用.结果显示,从固体培养基上分离得到的PSB-56解无机磷和有机磷能力最强.PGPR特性研究发现菌株PSB-37和PSB-56产IAA量最高,分别为40.22μg/mL和40.32μg/mL.分子学鉴定表明高效菌株PSB-37和PSB-56都属于类香味菌属(Myroides).分离到的高效解磷菌在盆栽试验中可以显著增加黄瓜的生长,以单菌处理对黄瓜的促生作用最明显,单菌处理较对照组其地上部鲜重增长率为117%.本研究从冰川退缩区筛选出了高效解磷促生的菌株资源,可供研发促生菌剂提供依据.(图4表5参38)

We explored the growth-promoting characteristics of cultivable phosphorus-dissolving bacteria in the Hailuogou glacier retreat area soil to acquire an in-depth understanding of useful bacterial resources available in this area and enrich the current resource pool of phosphorus-dissolving microorganisms.Twelve strains with the ability to dissolve inorganic and organic phosphorus were isolated and their plant growth-promoting characteristics were analyzed,followed by phylogenetic identification of the plant growth-promoting rhizobacteria(PGPR).The growth-promoting capacity of the PGPR isolates was determined in vitro by inoculation on cucumber plant in a pot experiment.Results suggest that PSB-56,isolated from solid medium,was the most efficient strain for dissolving inorganic phosphorus as well as organophosphorus compounds.Moreover,the phosphorus-dissolving strains PSB-37 and PSB-56 had the highest IAA activities,producing 40.22μg/mL and 40.32μg/mL IAA,respectively.The high-efficiency strains,PSB-37 and PSB-56,were identified as Myroides sp.In addition,the isolates significantly increased the growth and biomass of cucumber plants.Compared with control,fresh weight of the shoots increased by 117%after a single-strain treatment.The screened strains in the Hailuoguo glacier retreat area can be valuable for development of plant growth-promoting inoculants.