黄瓜耐盐根际促生菌的筛选及评价

Screening and evaluation of the salt-tolerant plant growth-promoting rhizobacteria on cucumber

为获得具有较高耐盐能力的根际促生菌并探究其对黄瓜幼苗耐盐性的影响,对5株菌株的生化特性进行测定,并通过耐盐盆栽试验初步筛选出HG15-7、NSY1、NSY50等3株耐盐促生菌株,进一步通过盆栽试验比较了3株耐盐促生菌株对黄瓜幼苗生长、光合作用及抗氧化代谢的影响。结果表明,耐盐促生菌株均具有较高的ACC脱氨酶活性和IAA合成能力,接种耐盐促生菌株均可不同程度提高盐胁迫下黄瓜幼苗的株高、茎粗、叶片数、叶绿素含量和净光合速率,其中耐盐促生菌株NSY50处理效果最佳,150 mmol·L^(-1) NaCl处理下分别较对照提高49.63%、8.27%、25.00%、17.19%和9.29%,相对电导率及丙二醛含量分别较对照降低21.81%和22.22%,减轻盐胁迫对黄瓜幼苗的氧化伤害,进而增强黄瓜幼苗耐盐性。NSY50具有进一步研究开发利用的潜力。

In order to obtain plant growth-promoting rhizobacteria with high salt-tolerant ability,we determined the biochemical characteristics of five strains and conducted pot experiment to explore their influence on the salt-tolerance of cucumber seedlings.HG15-7,NSY1,and NSY50,were screened as salt-tolerant plant growth-promoting bacteria.The effects of three salt-tolerant plant growth-promoting strains on growth,photosynthesis and antioxidant metabolism of cucumber seedlings were compared by pot experiment.The results showed that the salt-tolerant plant growth-promoting strains had high ACC deaminase activity and IAA synthesis ability.The inoculation of salt-tolerant plant growth-promoting strains could improve the growth and reduce the oxidative damage of salt stressed-cucumber seedlings.Among the 3 salt-tolerant plant growth-promoting strains,NSY50 has the best effect.Compared with the control,inoculation of NSY50 increased the plant height,stem diameter,leaf number,chlorophyll content and net photosynthetic rate by 24.60%,8.27%,25.00%,17.19%and 9.29%,respectively and reduced the relative conductivity and malondialdehyde content by 21.81%and 22.22%under 150 mmol·L^(-1) NaCl treatment.NSY50 has the potential for further research and development.