中文摘要：

试验采用三亲本杂交法将cfp基因导入一株有效性较高的菜豆根瘤菌SC18，获得了一株带cfp基因标记的菌株SC18-cfp。对SC18-cfp行性状、标记基因的遗传稳定性检测，结果表明，cfp基因不仅能有效表达，而且性状稳定。随机挑取SC18-cfp的10个转移结合子在无氮砂培条件下进行标记菌株与亲本菌株在3个菜豆品种上的竞争结瘤试验。结果证实，10个转移结合子在供试植物根系上的占瘤率均接近50％，其有效性和竞争结瘤能力与亲本菌株间的差异不显著，品种间的差异性不显著；在控制田间试验中SC18-cfp比土著根瘤菌的竞争结瘤能力强，在品种A、B、C上的占瘤率分别达到了57．8％、60．0％、55．6％。接种SC18的植株干重、全氮量、叶绿素含量和豆荚产量均显著高于对照。

英文摘要：

One strain SC18 - cfp marked with cfp gene was obtained by thri - patental mating. The results showed that cfp gene could express in SC18 - cfp and kept stabile, by detecting the expression and stability of SC18 - cfp.The result of pot experiment in nitrogen- free sand indicated that the competitiveness and effectiveness of the marked strain were not significantly different with the parental strain. Using the cfp marked gene to study competitive ability of SC18 - cfp with soil indigenous rhizobia under controlled conditions in field experiment on three phaseolus culitivars, we found that the SC18 - cfp had higher nitrogen fixing efficiency and stronger competitive ability than that of the soil indigenous strains. Its nodule occupancy on three cultivars of phaseolus vulgaris was 57.8%, 60.0%, 55.6% respectively.Inoculation of strain SC18 could significantly increase the plant shoot dry weight, chlorophyl content, total nitrogen and the plant yield.