外源类黄酮对大豆根瘤菌趋化性与结瘤效果的影响

以慢生型大豆根瘤菌(Bradyrhizobium japonicum)2-39为供试菌株,分别以不同浓度(5,10,15,20,25μg·mL~(-1))的大豆黄素、4-甲基伞形酮、金雀异黄酮、芒柄黄花素为诱导物,利用毛细管培养法对趋化的根瘤菌进行定量测定,研究不同种类和不同浓度的外源类黄酮对大豆根瘤菌趋化性的影响。选取对根瘤菌趋化性影响显著的外源类黄酮与大豆嫩丰16进行盆栽试验,进一步探究外源类黄酮对大豆结瘤效果的影响。结果表明:4种外源性类黄酮中,大豆黄素和金雀异黄酮对根瘤菌的趋化作用显著强于其它试验组,其最适作用浓度为15μg·mL~(-1)。盆栽试验结果显示:外源类黄酮大豆黄素和金雀异黄酮同时加入能够有效促进大豆结瘤。

The Chemotaxis and Nodulation Effect of Soybean Rhizobium on Exogenous Flavonoids

In the study,Bradyrhizobium japonicum 2-39 was used as test strain.Exogenous flavonoids such as daidzein,4-methylumbelliferone,genistein and formononetin with different concentration (5,10,15,20,25 μg·mL-1) were selected as the inducer,respectively.Aimed to study the chemotaxis effect of Bradyrhizobium japonicum 2-39 to exogenous flavonoids of different kinds and concentrations,capillary culture method was utilized to quantify the number of rhizobia colonies.The exogenous flavonoids which have significant effect on chemotaxis of Bradyrhizobium japonicum 2-39 and soybean genotype NF-16 were selected in the pot experiment to further explore the nodulation effect of soybean.The results indicated that daidzein and genistein exert more significant effect on Bradyrhizobium japonicum 2-39 compared with other group.The optimum concentration of daidzein and genistein was 15 μg·mL-1.The results of pet experiment showed that simultaneous addition of daidzein and genistein could effectively stimulate soybean nodulation.