产多胺菌鉴定及其对黄瓜幼苗的促生作用研究

Identification of polyamine-producing bacteria and its effect on the growth of cucumber seedlings

利用PCR技术克隆细菌DJ的16S rDNA序列,片段回收纯化后与载体连接,结合16S rDNA测序法鉴定产多胺菌DJ,确定所分离的产多胺菌的种属,利用高效液相色谱法检测DJ菌上清液中多胺成分,以DJ菌液浸泡黄瓜种子2 h,播种于1/2 MS培养基,种子周围滴加Na_(2)CO_(3)/NaHCO_(3)混合盐溶液,7~10 d后测定盐碱胁迫条件下黄瓜幼苗鲜重、侧根数及茎高,研究菌体培养液中多胺成分及该菌在盐碱胁迫条件下对黄瓜幼苗的促生作用。结果表明:通过16S rDNA序列对比确定DJ菌为阴沟肠杆菌(Enterobacter cloacae)。经高效液相色谱检出DJ菌上清液中含有腐胺和亚精胺,且腐胺含量较高。在盐碱胁迫条件下进行DJ菌浸种后,试验组幼苗侧根数平均为17根·株-1,幼苗平均鲜重为0.42 g,平均茎高为6 cm,而对照组侧根数平均为14根·株-1,平均幼苗鲜重为0.28 g,平均茎高为3.8 cm。试验组与对照组差异显著。综上,盐碱胁迫条件下DJ对黄瓜幼苗具有明显的促生作用。

The 16S rDNA sequence was used to identify DJ bacteria, polyamine components in DJ supernatant were analyzed by High performance liquid chromatography, and the fresh weight, lateral roots and stem height of cucumber seedlings were detected under saline-alkali stress conditions. Strain identification of the DJ bacteria, the polyamine components in DJ supernatant and their effects on cucumber seedlings were analyzed under saline-alkali stress conditions. Results showed that: The 16S rDNA sequence comparison confirmed that DJ bacteria was E.cloacae, Putrescine and spermine were confirmed in DJ bacteria supernatant. The average number of lateral roots of seedlings in the experimental group was 17 roots·plant^(-1), the average fresh weight was 0.42 g, and the average stem height was 6 cm, while the average number of lateral roots in the control group was 14 roots·plant^(-1), the average fresh weight was 0.28 g, and the average stem height was 3.8 cm. The polyamine-producing bacteria DJ(E.cloacae)can promote the growth of cucumber seedlings under the saline-alkali stress conditions.