三江源区燕麦根际优良促生菌筛选、鉴定及培养特性研究

Screening and identification and culture characteristics of excellent growth promoting bacteria in the rhizosphere of Avena sativa L.in the Sanjiangyuan Region

为了丰富三江源区主要栽培牧草根际促生菌资源,本研究从燕麦(Avena sativa L.)根际中筛选促生菌,再通过分析菌株的固氮、溶磷等特性筛选出优良菌株,并对其进行分子生物学鉴定和在不同温度、盐碱和pH条件下的生长状况测定。结果表明:从燕麦根际中可筛选出9株优良促生菌,归属于假单胞菌属(Pseudomonas sp.)、短小芽孢杆菌属(Bacillus pumilus sp.)和节杆菌属(Arthrobacter sp.);优良菌株最适生长温度为20~35℃,最适盐度为3%~5%,最适酸碱度为4.5~6.5,其中菌株IP-3ZQ21b和N-4GN032c具有较高耐盐性。综合评定,菌株IP-3ZQ21b和N-4GN032c在较高盐度条件下生长良好,在盐碱土壤改良或植物耐盐育种中具有潜在的应用价值。

The growth promoting bacteria from the rhizosphere of Avena sativa L.is screened to enrich the rhizosphere growth promoting bacteria resources of the main cultivated forage in the Sanjiangyuan Region.Excellent strains are selected by analyzing their nitrogen fixation and phosphorus solubilization characteristics.Molecular biology identification and growth status determination are conducted under different temperature,saline-alkali and pH conditions.The results show that the 9 strains screened from the rhizosphere of Avena sativa L.belong to Pseudomonas sp.,Bacillus pumilus sp.and Arthrobacter sp.respectively.The optimal growth temperature for excellent strains is 20~35℃.The optimal salinity is 3%~5%.The optimal growth pH value is 4.5~6.5.Among them,IP-3ZQ21b and N-4GN032c show higher salt tolerance.Comprehensive evaluation shows that IP-3ZQ21b and N-4GN032c grow well under high salinity conditions,indicating potential application value in saline-alkali soil improvement or plant salt-tolerant breeding.