不同盐分条件下植物促生菌对燕麦和黑麦草幼苗的促生效应

Effects of plant growth-promoting rhizobacteria on the seedling growth of oat and annual ryegrass at various salt concentrations

从盐生植物根际土中分离得到4株含1-氨基环丙烷-1-羧酸(ACC)脱氨酶的植物促生菌(PGPR),通过无菌育种袋栽培试验,考查其在不同盐分条件下对燕麦和黑麦草幼苗的促生效应。结果表明,4株菌对5 g/kg或10 g/kg NaCl盐分胁迫下的燕麦和黑麦草幼苗均表现出显著地缓解促生效应,其中假单胞菌属S1最显著,10 g/kg NaCl比无NaCl时促生作用更大。4株PGPR的ACC脱氨酶活性与植物生长参数(根长和下胚轴长)之间具有极显著的正相关性(Pearson相关系数>0.81)。

Four strains of plant growth- promoting rhizobacteria （PGPR） containing 1 - aminocyclopropane- 1- carboxylic acid （ACC） deaminase were isolated from the rhizosphere of salty plants, and their effects on the seedling growth of oat and annual ryegrass at various salt concentrations in gnotobiotic growth pouch assay were investigated. These four bacterial isolates, especially Pseudomonas sp. S1, alleviated greatly salt stress and promoted significantly the seedling growth of oat and annual ryegrass under either 5 g/kg or 10 g/kg NaCl stress. Compared with control （no NaCl）, more plant promotion was observed under 10 g/kg NaCl stress. The greatly significant positive correlations between ACC deaminase activity of four bacterial isolates and plant growth pa- rameters （root length and shoot length） were observed （Pearson correlation co- effcients 〉 0.81 ）.