田菁种子内生菌的分离及其对萌发的影响

Isolation of Endophytic Cultures From Sesbania cannabina Seeds and Their Effects on Germination

植物-微生物联合修复是改良盐碱地的重要生物策略,其中获得有效的微生物菌株是关键所在。为了获得更多的植物促生菌菌种资源,以滩涂耐盐植物田菁种子为材料分离可培养内生菌。分离纯化得到了79株菌,主要集中分布在Bacillus、Azorhizobium、Cellulosimicrobium三个属。菌株SC45、SC59、SC60、SC24、SC5、SC17六株菌可分泌吲哚乙酸(indole-3-acetic acid,IAA)。SC45、SC59、SC60具有溶解无机磷能力,其中SC60分解无机磷能力最高为(207.9±14.29)mg·L-1,且SC45具有产铁载体能力。种子萌发试验结果显示,与对照相比,SC45、SC60、SC59、SC17对田菁种子的活力系数分别可提高13.3%、14.1%、29.9%、26.7%。且SC60和SC17菌株浸种可显著促进胚根的发育,胚根占比提高了29.5%和13%。上述结果表明,Bacillus SC60可分泌IAA和溶解无机磷,提高种子活力,促进胚根发育,可作为田菁促生菌应用于农业生产。

Plant-microorganism combined bioremediation is important for saline-alkali land remediation, and the key is to obtain effective microbial strain. In order to obtain more resources of plant growth promoting bacteria(PGPB), the cultivable endophytes of S. cannabina seeds were used to isolate endophytic culture. 79 strains were isolated from S. cannabina seeds, belonging to Bacillus, Azorhizobium, Cellulosimicrobium. Six strains producted IAA were selected to measure the phosphate solubilization and siderophore production. SC45, SC59, SC60 had phosphate solubilization, among them, SC60 had the highest production with(207.9±14.29) mg·L-1, and SC45 had siderophore production. Germination experiment showed that six strains could promote germination potential and seed vigor. SC45, SC60, SC59 and SC17 increased the vigor coefficient of S. cannabina seeds by 13.3%, 14.1%, 29.9% and 26.7%, respectively. Soaking seeds with SC60 and SC17 strains also promoted radicle development, and the radicle ratios increased by 29.5% and 13%. Above results showed that SC60 had the IAA activity and phosphate solubilizing activity, and could be used as plant growth-promoting bacteria to promote plant radicle development and increase seed vigor, so it could be as potential PGPB to promote S. cannabina growth.