Abstract:

Endophytic bacterium 265ZY3 was isolated from the Stipa capillata in the alpine meadow. The strain was identified by 16S rDNA sequence analysis. The biological characteristics of the endophytic bacterium such as antibacterial spectrum, IAA secretion, phosphate solubilization and nitrogen fixation were investigated. Results showed that the inhibitive rates of the identified strain to Phoma foveata, Colletotrichum coccodes and Fusarium avenaceum were 81.65%, 87.84% and 72.64%, respectively. The concentration of IAA secreted by 265ZY3 were 42.33 mg·L^-1 and 38.59 mg·L^-1 in the King medium with 100 mg·L^-1 tryptophan and without tryptophan, respectively. The 265ZY3 strain dissolved inorganic phosphorus and organic phosphorus. Moreover, the dissolving capacity of the strain for inorganic phosphorus was about 68 times higher than for organic phosphorus. Meanwhile, the strain had the ability of nitrogen fixation. The strain was identified as Bacillus amyloliquefaciens by the analyses of both 16S rDNA sequence homology and morphological characteristics.

Key words: Stipa, Endophytic bacteria, Biological functions, Identification

摘要：

对高寒草地针茅（Stipa capillata L.）内生细菌265ZY3进行了抗菌、产IAA、溶磷、固氮等生物学特性的研究，并通过16SrDNA序列分析对其进行了鉴定。结果表明：265ZY3对马铃薯坏疽病菌（Phomafoveata）、马铃薯炭疽病菌（Colletotrichum coccodes）和马铃薯枯萎病菌（Fusarium avenaceum）均有良好的抑制作用，抑菌率分别为81.65%，87.84%和72.64%；在不含色氨酸和含100mg·L^-1色氨酸的King培养液中分泌IAA的量分别为38.59mg·L^-1和42.33mg·L^-1；能溶解无机磷和有机磷，且溶解无机磷的能力是有机磷的68倍；同时，具有固氮能力。结合形态学特征，通过16SrDNA序列同源性分析，将265ZY3初步鉴定为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）。

关键词: 针茅, 内生细菌, 生物学特性, 鉴定