水稻种子内生细菌多样性及其分泌植物生长素能力的测定

Diversity of endophytic bacteria in rice seeds and their secretion of indole acetic acid

【目的】探讨水稻种子内生细菌的多样性并测定其分泌IAA能力。【方法】采用传统的可培养方法分离水稻种子内生细菌,并通过16S rRNA基因序列分析初步确定分离菌株的系统发育地位,利用比色法进一步对不同种类菌株产植物生长素(IAA)能力进行定性、定量检测。【结果】共分离纯化获得66株内生细菌菌株,分属于5个类群的15个属26个种。以26株细菌为代表对其进行分泌生长素(IAA)能力的定性及定量测定,共发现19株细菌可分泌生长素或其类似物,其中Z10、Z17、Z14和Z20 4株内生细菌具较强的分泌植物生长素能力。【讨论】分离得到的内生细菌表现了水稻种子内生细菌的多样性,其中某些细菌对植物有一定的促生功能。

[ Objective] This study aimed to investigate the diversity of endophytic bacteria isolated from rice seeds, and screen indole acetic acid secrecting srtains. [ Method] Conventional culture-dependent methods were used to isolate the endopytic bacteria from rice seeds. Phylogenetic analysis was done based on partial 16s rRNA gene sequences. The ability to indole acetic acid secretion of tested strains was analyzed qualitatively and quantitatively by colorimetry. [ Result] In total 66 isolates were identified as belonging to 26 species of 15 genera of 5 phyla. Of them 26 strains were chosen to test indole acetic acid secretion. Four isolates had more ability of indole acetic acid secretion; they belonged to the genera of Staphylococcus, Rhizobium, Microbacterium and Methylobaeterium. [ Conclusion] The endophytic bacteria in rice seeds are diverse. Some of them could produce indole acetic acid.