根瘤菌与烯效唑互作对大豆生长及固氮的影响

以根韦氏中华根瘤菌(Sinorhizobium fredii)和埃尔坎慢生根瘤菌(Bradyrhizobium elkanii)为研究材料,以0.001~100 mg·L~(-1)浓度的烯效唑培养两种根瘤菌,探究烯效唑对根瘤菌生长的影响。结果表明:供试烯效唑浓度范围内大于10 mg·L~(-1)时抑制根瘤菌数量,烯效唑浓度为1 mg·L~(-1)时对根瘤菌数量具有促进作用。大豆以1 mg·L~(-1)浓度烯效唑浸种,每2.5 kg土壤拌有30 m L对数生长期的根瘤菌菌液,在花荚期测定大豆叶片与根系的SOD、POD、CAT酶活力、丙二醛含量(MDA)及大豆根系酰脲含量,确定根瘤菌与烯效唑互作对大豆生长及共生固氮的影响。结果显示:与根瘤菌处理相比,根瘤菌与烯效唑互作可降低大豆植株中MDA含量达40%~60%,提高大豆根系酰脲含量达5%~8.4%,但对测定的3种酶活性影响不显著。试验结果证实了根瘤菌与烯效唑互作可提高大豆固氮能力,降低MDA含量。

Effect of Uniconazole and Rhizobium Interaction on Growth and Nitrogen Fixation in Soybean

Taking strains of Sinorhizobium fredii and Bradyrhizobium elkanii as the research materials,the concentration of uniconazole from 0.001 to 100 mg·L-1 were used to determine the influence of uniconazole interacting with those two strains.The results showed that the amount of S.fredii and B.elkanii was inhibited when the concentration of uniconazole was higher than 10 mg·L-1,but the amount of these two strains was promoted when the concentration of uniconazole was 1 mg· L-1.Soybean seed was presoaked by uniconazole with 1 mg·L-1and 30 mL Rhizobium liquid in logarithmic growth phase was mixed with soil per 2.5 kg.The enzyme activities of SOD,POD and CAT,the MDA level in soybean leaf and root,the ureide content in root were assayed in flowering-poding phase to reflect the effects of those two strains and uniconazole interaction on soybean.The results confirmed that those two strains and uniconazole interaction were effectively reduced the MDA level about 40％-60％ in soybean roots and leaves,the ureide content in soybean root were increased 5％-8.4％,however,the three enzyme activities were not significantly affected.The experimental results confirmed that Rhizobium interacting with uniconazole could increase nitrogen fixation ability of soybean and reduce MDA content.