根际促生细菌对甘薯苗期生长的影响及其促生机制

Effects of Rhizosphere Growth-Promoting Bacteria on Growth of Sweet Potato(Ipomoea batatas L.)Seedlings and Its Growth-Promoting Mechanism

以甘薯(Ipomoea batatas L.)为供试作物,研究分离自连作太子参土壤的解淀粉芽孢杆菌C05(C05)与枯草芽孢杆菌G03(G03)的体外促生能力及根际接种这两株细菌对甘薯幼苗生长和盆栽土壤理化性质、土壤主要功能酶活性的影响,以期为植物根际有益细菌的开发利用提供理论依据。结果表明,接种C05、G03可以显著提高甘薯幼苗的主蔓长、最大叶面积、地上部鲜重和干重、地下部干重和叶片叶绿素a、b含量,其中C05对甘薯幼苗的促生效果最为显著。接种C05、G03能够改善栽培土壤营养构成,提高土壤脲酶、蔗糖酶、酸性磷酸酶、过氧化氢酶活性,诱导甘薯抗病基因H1N1和促生基因ctd1、ERF2的表达。综合认为,解淀粉芽孢杆菌C05与枯草芽孢杆菌G03具有体外促生能力,根际接种这两株细菌一定程度上可以促进甘薯幼苗生长。

With sweet potato(Ipomoea batatas L.)as experimental material,the growth promotion ability in vitro of Bacillus amyloliquefacens C05(C05)and B.subtilis G03(G03)isolated from the continuous cropping soil of Radix pseudostellariae and the effect of rhizosphere inoculation of these two bacteria on the growth of sweet potato seedlings and the physical and chemical properties of potted soil,as well as the activity of major functional enzymes in the soil were studied,so as to provide theoretical basis for the development and utilization of beneficial bacteria in the plant rhizosphere.The results showed that inoculation with C05 and G03 could significantly increase the main vine length,maximum leaf area,aboveground fresh and dry weight,un-derground dry weight,chlorophyll a and b contents of sweet potato seedlings,among which,C05 had the most significant effect on the growth.C05 and G03 treatments could improve the nutrient compositions of cultivated soil,increase the activities of urease,sucrase,acid phosphatase and catalase in soil,and induce the expres-sions of diseaseresistance gene H1N1,growth-promoting genes ctd1 and ERF2 of sweet potato.In conclusion,B.amyloliquefacens C05 and B.subtilis G03 had growth-promoting ability in vitro,and rhizosphere inoculation of these two bacteria could promote the growth of sweet potato seedlings to a certain extent.