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为给冬枣(Ziziphus jujube Mill.)生物肥料的研制和生产提供优良菌株资源,利用梯度稀释法和三区划线法从冬枣根际土壤中分离、纯化出832株细菌分离物,进一步通过小麦叶片保绿法和萝卜子叶增重法筛选出效果较好的3株,分别记为DZ1、DZ2和DZ3.这3株细菌分离物均不产异戊烯基腺嘌呤,其中DZ1和DZ2分泌反式玉米素(分别为368.73和598.46 ng mL-1)、激动素(273.56和193.16 ng mL-1)和吲哚乙酸[9.24和13.85μg mL–1(OD600 nm)–1],而DZ3分泌激动素(175.4 ng mL-1)和反式玉米素(314.34 ng mL-1),但不产吲哚乙酸.通过形态学观察、生理生化测定、16S rRNA基因测序及系统发育树分析,初步确定DZ1和DZ2为枯草芽孢杆菌(Bacillus subtilis),DZ3为芽孢杆菌属(Bacillus sp.).最后通过盆栽试验对这3株细菌分离物的促生效果进行比较,结果发现,DZ1、DZ2和DZ3,尤其是DZ1,对冬枣细根的生长及地上部干物质积累有积极作用,可作为研制冬枣生物肥料的优良菌株资源.
In order to provide excellent strain resources for the development and production of Ziziphus jujube Mill. Bio-fertilizer, 832 bacterial isolates were isolated from rhizosphere soil of jujube by gradient dilution and three-division line method, The results showed that DZ1, DZ2 and DZ3 did not produce isoprenyladenine, of which DZ1 and DZ2 secreted trans (368.73 and 598.46 ng mL-1, respectively), kinetin (273.56 and 193.16 ng mL-1) and indole acetic acid [9.24 and 13.85 μg mL-1 (OD600 nm) -1] (175.4 ng mL-1) and trans-zeatin (314.34 ng mL-1), but did not produce indole-acetic acid.According to morphological observation, physiological and biochemical determination, 16S rRNA gene sequencing and phylogenetic tree analysis, DZ2 is Bacillus subtilis and DZ3 is Bacillus sp.Through pot experiment, the promoting effect of these three bacterial isolates was compared and found that DZ1, DZ2 and DZ3, especially DZ1 has a positive effect on the growth of fine roots and the accumulation of dry matter in aboveground parts of jujube, Development of jujube bio-fertilizer excellent strain resources.