荧光假单胞杆菌RB-42 RB-89的趋化性与烟草根部定殖研究

烟草PGPR(PlantGrowth PromotingRhizobacteria)菌株RB 89、RB 42对烟草根部收集液有较强的趋化性。在稀释浓度为10-5时,RB 89、RB 42的趋化值依次为1 79、1 83。RB 42和RB 89对氨基酸趋化性差异显著,对酪氨酸、脯氨酸、甘氨酸、笨丙氨酸表现出较强的趋化性,对组氨酸、苏氨酸没有表现出趋化性;RB 42和RB 89菌株对有机酸的趋化性没有明显区别,只是RB 42对乳酸的趋化性表现得比对其它有机酸的强些;菌株对糖类物质的趋化性最弱。菌株RB 89、RB 42在烟株根表的定殖受灭菌、趋化剂影响较大,土壤灭菌、趋化剂处理可增加菌株在根表的定殖量。

Chemotaxis of pseudomonas fluorescens RB-42 RB-89 towards roots exudates and colonization of tabacco roots

Tabocco PGPR strains Pseudomonas fluorescens RB-89 and RB-42 had high dgree chemotaxis towards roots exudates.The Che are 1.79 and 1.93 of P. fluorescens RB-89 and RB-42 at five hundreds times dilution of the condense of tobacco roots exudates . The two strains had higher chemotaxis towards amino acid than organic acid and the carbohydrates. The chemotaxis of P. fluorescens RB-89 and RB-42 showed great difference among amino acids, the strains had a high chemotaxis toward Tyr Pro Gly Phe but showed no chemotaxis toward His and Thr. The strains showed almost no different chemotaxis to organic acid but showed higher chemotaxis to lactic acid than ohters. The strains showed no chemotaxis toward the carbohydrates. The colonization on tabacco roots of P. fluorescens RB-89 and RB-42 were deeply influenced by soil sterilization and chemotaxic materials and the colonization density were improved greatly with soil sterilization and chemotaxic materials.