缺硼、不同光强及外源葡萄糖对大豆根瘤固氮活性的影响

以大豆超结瘤突变体nts382及其亲本Braggcv．为试验材料，研究了正常供硼和缺硼条件下，不同光强和外源葡萄糖对大豆根瘤固氮活性的影响。结果表明，缺硼时根瘤固氮酶活性显著下降，此时降低光强并没有使根瘤固氮酶活性进一步下降，但使根瘤数减少；外源施用葡萄糖也不能提高根瘤固氮酶活性。在正常供硼情况下，低光强降低了根瘤固氮酶活性，并且使根瘤数和根瘤干重减少，外源施用葡萄糖也增加根瘤固氮酶活性。这说明了在缺硼条件下，根瘤固氮酶活性的下降并不是由于碳水化合物供应不足所造成的。

EFFECTS OF BORON DEFICIENCY, LIGHT INTENSITY AND EXOGENOUS CARBOHYDRATE SUPPLY ON SYMBIOTIC NITROGEN FIXATION IN SOYBEAN PLANTS

The effect of boron deficiency, light intensity, supply with exogenous glucose and their interactions on nitrogenase activity of nodules in soybean plants were studied in nutrient solution under controlled condition. The absence of boron in the culture medium resulted in an inhibition of nitrogenase activity. Lower intensity in boron free medium didn't decrease nitrogenase activity. but supplying with glucose could not prevent the decrease of nitrogenase activity, in spite of increase of sucrose content in nodules after exogenous glucose. These results indicate that the decrease of nitrogenase activity of nodules under the boron-deficiency stress was not due to carbohydratedeficiency.