锦鸡儿根瘤菌的抗逆性及其在寄主上结瘤、促生效果的研究

THE ANALYSIS OF RESISTANCE OF R. caragana AND ITS NODULAR,CATALYSE EFFECTS ON Caragana

对3株分离于内蒙古的锦鸡儿根瘤菌进行耐盐性、耐酸碱性、唯一碳、氮源利用能力的研究,并用这些菌株对锦鸡儿进行蛭石-土壤回接试验筛选固氮高效的菌株。结果表明,菌株2-S1和5-9表现出较好的耐酸碱性,可忍耐p H范围为6.0～10.0,最佳生长p H为7-8;菌株2-S1的耐盐性最好,可在盐浓度为2%的培养基上生长,菌株DK44和5-9次之,最高可忍耐盐浓度为1%;参试的11种碳源,有8种均可被3种根瘤菌利用,3株根瘤菌均不能利用柠檬酸钠为唯一碳源,菌株5-9利用碳源的能力最强,范围最广;唯一氮源利用实验显示,除（NH4）2SO4不能被菌株DK44所利用外,所有参试的11种氮源均可被3株菌株利用,菌株5-9可充分利用7种氮源,是利用氮源能力最强的菌株;盆栽回接试验表明,3株根瘤菌均表现出较好的结瘤能力以及对植株不同程度的促生作用,菌株5-9对锦鸡儿的生长特性均表现出明显的促生作用。结论,菌株5-9有着良好的耐酸碱性以及较强的碳、氮源利用能力,同时能够明显的促进植株生长,是良好的潜力菌株。

Three Rhizobium strains isolated from cagarana in three different drought area of Inner Mongolia West were tested on their tolerance to Na CI and p H,and the utilization of only carbon source and nitrogen source,and were also inoculated to the cagarana using vermiculite and soil in order to Screening of effective strain. The results showed： strain 2- S1 and 5- 9 showed the better acid- alkali- resistant ability,supportability p H value of 6. 0- 1. 0,and optimal growth on medium with p H value of 7- 8; The salt- resistant ability of strain 2- S1 was the best,which could be grown on the medium with salt concentration of 2%,and the maximum tolerance to salt concentration of strain 5- 9 was 1%; Among 12 kinds of carbon sources tested,8 carbon sources can be utilized by all of 3 strains,all of strains can not using sodium citrate,the ability that 5- 9 strain using carbon source was the strongest and the most widely; The experiment of only nitrogen source showed all of 11 nitrogen sources can be utilized by 3 strains except the nitrogen sources of（ NH4）2SO4can not be utilized by the strain of DK44,5- 9 strain can make full use of 7 nitrogen sources,and had the strongest ability of utilized nitrogen source; Pot inoculation test showed that the 3 strains of rhizobium showed better nodulation ability and different levels effect of promoting plant growth,5- 9 strains showed obvious growth promoting effect on growth characteristics of Caragana. Conclusion： the strain 5- 9 has a good tolerance for acid and alkali,and the best ability to use carbon and nitrogen sources,and can obviously promote the growth plant,it is a good potential strain.