根际促生菌对棉苗盐碱胁迫的缓解效应

为探究根际促生菌(PGPR)对棉苗盐碱胁迫下的缓解效应,采用1株具ACC脱氨酶活性的PGPR菌株P2处理棉花,测定不同质量浓度盐碱胁迫下棉花的相关生理指标。结果表明,在盐碱胁迫下,PGPR能缓解棉苗所受的毒害,且随着盐碱质量浓度的增大缓解作用越明显。在10g/L的混合盐碱胁迫下,P2菌株处理后棉花种子的萌发率提高185%;可溶性糖质量分数升高69.55%,可溶性蛋白质量分数升高43.67%,提高棉花的渗透调节能力;丙二醛摩尔浓度下降35.33%,过氧化物酶活性升高64.9%,降低胁迫对棉花的伤害;同时,叶片的光合能力、根系活力及根系发育情况也明显优于无菌处理。表明具有ACC脱氨酶活性的菌株P2能有效缓解盐碱胁迫对棉苗的抑制,提高棉苗的抗盐碱性。

Mitigative Effect of PGPR on Cotton Seedings Subjected to Salt-alkaline Stress

To explore mitigation effect of plant growth-promoting rhizobacteria (PGPR) on cotton seedlings under salt-alkaline stress,a PGPR strain P2 with ACC deaminase activity was adopted to treat cotton seedlings,and determined related physiological indexes of cotton seedlings under different concentration of salt-alkaline stress.The results showed that under salt-alkaline stress,PGPR alleviated the toxicity of salt-alkaline to cotton seedlings,and with the increase of salinity concentration,its relief effect was more obvious.Under the mixed salt and alkaline stress of 10 g/L concentration,the germination rate of cotton seeds treated with P2 strain increased by 185%; soluble sugar content increased by 69.55%,soluble protein content increased by 43.67%,which improved the osmotic regulation ability of cotton; MDA content decreased by 35.33%,POD activity increased by 64.9%,which reduced the stress damage to cotton.Meanwhile,the leaf photosynthetic capacity,root activity and development was also significantly better than those of the control group.These results showed that the strain P2 with the ACC deaminase activity effectively alleviated the suppression of salt-alkaline stress on cotton seedlings,and improved salt tolerance of cotton seedlings.