重组质粒pHN32对花生根瘤菌固氮的影响

通过三亲本杂交将大豆根瘤菌高效基因工程菌株HN32所携带的增效重组质粒pHN32引入一株快生型花生根瘤菌菌株85-7和另一株慢生型花生根瘤菌菌株co2-5中。花生盆栽结瘤试验结果统计分析表明:p的HN32载体质粒pLAFR1对根瘤菌85-7和co2-5的固氮功能没有影响;pHN32对85-7固氮影响不论在植株干重方面还是在固氮酶活方面统计学上都不显著;而对co2-5则植株干重提高了25.7％,存在极显著差异,固氮酶活尽管提高了51.8％,但统计学上不显著。根瘤中分离的Tc~r根瘤co2-5(pHN32)中的pHN32EcoR1酶切分析表明:pHN32没有发生结构上的变化且固氮增强作用可能由3.7kb外源片段引起。

THE EFFECT OF RFCOMBINANT pLASMID pHN32 ON FIXATION OF GROUNDNUT RHIZOBIM STRAIN

By tri-parental mating, pHN32,a enhancing factor of B. iaponicum 22-10 was conjugated individually with a fast-growth groundnut rhizobium strain 85-7 and a slow-growth groundnut rhizobium strain co2-5. The conjugaters were mixed respectively and used to inoculate groundnut plants in pot test. The results showed that pHN32 was no effect on the nitrogen fixation of strain 85-7, but the increase rates of 25.7% plant dry weight and 51.8% nitrogenase activity per plant were obtained by comparing with that of co2-5. the statistical analysis showed tht nitrogenase activity was not up to the significant level. pHN32 isolated from co2- 5 (pHN32) was digested with EcoRI and a 3.7kb foreign DNA fragment was identified.