厚荚相思树种根瘤菌的抗逆性研究

Study on stress tolerance of rhizobia isolated from Acacia crassicarpa

研究了27个分离自不同苗木类型(组培苗、实生苗、扦插苗)以及不同生态环境的厚荚相思根瘤菌菌株对温度、pH值、NaC1浓度的耐受性以及抗药性。结果表明:厚荚相思根瘤菌耐低温能力差,只有qx6-8能耐低温;只有sz2-5-2不具有耐碱性(pH值9),耐酸(pH值4,5)菌株有qz3-9,qx6-8;耐盐能力普遍较差,耐盐性较强(1.5%NaCl)的菌株有qz9-8、qx6-8、sx5-4;对Amp、Tc、Cm、Spc、Gm有较强的抗性作用,只有sz2-5-2对Km有抗性,不同菌株对抗生素的敏感性差异较大;扦插苗的根瘤菌的抗性总体比实生苗和组培苗根瘤菌的抗性强;菌株qx6-8具备多种优良抗性.

In order to research the stress-tolerant of rhizobium isolated from Acacia crassicarpa,27 strains of Acacia rhizobium,which were isolated from different seedlings（tissue culture seedlings,seedlings,cutting seedlings）Acacia plantation grown under different ecological environment,which were tested on their tolerance to temperature variation,pH,NaCl and drug resistance.The results indicate that only strain qx6-8 could grow at low temperature（4℃）,only strain sz2-5-2 was not tolerant to alkali（pH 9.0） and strain qx6-8,qz3-9 were tolerant to acid（pH 4,5）;Salt tolerance of the strains were general poor,strains of qz9-8,qx6-8 and sx5-4 could grow in media containing 1.5%NaCI;Most strains were resistant to Amp,Tc,Cm,Spc and Gm,only sz2-5-2 was resistant to Km.Different resistance of Acacia rhizobia to antibiotics was proved.Cutting seedlings generally were stronger than seedlings and tissue culture seedlings on the resistance of rhizobium.The strain qx6-8 had much strong resistance.