翅碱蓬内生细菌鉴定及耐盐促生作用研究

Identification of Endophytic Bacteria and Preliminary Research on Their Growth-promoting Effect under Salt Stress in Suaeda heteroptera Kitag

对盐生植物翅碱蓬的根、茎、叶组织进行分离,纯化,得到内生细菌79株,经形态学和理化特征鉴定并结合16S rDNA片段测序分析,表明这些内生细菌分别属于芽孢杆菌属(Bacillus)、不动杆菌属(Acinetobacter)、假单胞菌属(Pseudomonas)、黄单胞菌属(Xanthomonas)、盐单胞菌属(Halomonas)和泛菌属(Pantoea)。通过考察所分离到细菌对异缘植物小麦盐分胁迫下种子萌发率和幼苗生长的促进作用,筛选出2株能够显著提高小麦耐盐性的内生芽孢细菌SE48和SE4。150mM NaCl胁迫条件下,SE48和SE4处理小麦的干重分别增加43.6%和36.8%;甚至在300mM NaCl胁迫条件下,SE48仍能使小麦幼苗干重增加18.5%。这表明翅碱蓬的内生细菌可望用于宿主耐盐性的提高及盐碱地土壤的开发利用。

79 endophytic bacteria strains were isolated and purified from the roots,stems and leaves of a halophyte, Suaeda heteroptera. According to physiological and biochemical characteristics and 16S rDNA sequence analysis,these strains were classified into 6 different genera：BaciUus, Acinetobacter, Pseudomonas, Xanthomonas, Halomonas and Pantoea. According to the stimulation of endophytic bacteria to the seed germination and seedling growth of heterologous wheat under salt stress,two strains （SE48 and SE4）could significantly improve the salt tolerance of host plants. SE48 and SE4 could significantly promote the growth of wheat seedlings in the presence of 150ram NaC1 by increasing 31.37% and 40.21% of the dry weight,respectively. SE48 could even raise the dry weight by 18.5% under 300ram NaC1. The results showed that inoculation with endophytie bacteria could serve as an environmentally-friendly and economical alternative to the amelioration of increasingly saline soils.