氮、磷对根瘤菌液处理下甘草根瘤生长及固氮活力的影响

Effects of N and P on root nodules growth and nitrogen fixation of Glycyrrhiza uralensis Fisch.treated with Rhizobium solution

目的探究不同水平的氮素和磷素对根瘤菌液处理下甘草根瘤生长及固氮活力的影响。方法设置甘草播种盆栽试验,对盆栽土壤施加根瘤菌液,播种浸泡根瘤菌液的甘草种子,采用不同水平的氮素和磷素处理,调查取样,测定甘草生长指标、成分含量及根瘤固氮活力。结果随着氮素和磷素水平的增加,甘草根部及根瘤的生长指标呈先升后降的趋势,其中N2和P2处理的甘草根长、根粗、根鲜重最大,单株结瘤数最多,分别为对照组的5.35倍和2.14倍;N1和P1处理的根瘤单重最高,分别为对照组的4.49倍和5.43倍。根瘤豆血红蛋白含量随着氮素水平的增加呈先升后降的趋势,以N2处理的含量最高,为对照组的1.96倍;随着磷素水平的增加根瘤豆血红蛋白的含量呈下降趋势。甘草酸和甘草苷含量随着氮素水平的增加先升高后下降,其中N2处理的含量最高;随着磷素水平的增加甘草酸和甘草苷含量呈上升趋势。结论在施加根瘤菌液的条件下,适量的氮素、磷素可以促进甘草生物量和活性成分积累,促进甘草结瘤,提高根瘤的固氮活力。

Objective To determine the effect of N and P levels on the growth of root nodules and nitrogen fixation of Glycyrrhiza uralensis Fisch.treated with Rhizobium solution.Methods A pot experiment of Glycyrrhiza uralensis Fisch.sowing was set up,Rhizobium solution was added to the pot soil.Glycyrrhiza uralensis Fisch.seeds soaked in Rhizobium solution was sowed after they were treated with different levels of N and P.The growth index,content of active components of Glycyrrhiza uralensis Fisch.and nitrogen fixation index of root nodules were determined.Results With the increase of N and P concentration,the growth indexes of Glycyrrhiza uralensis Fisch.roots and nodules first increased and then decreased.Glycyrrhiza uralensis Fisch.treated with N2 and P2 showed longer,thicker and heavier roots,and more nodules,which was 5.35 times and 2.14 times of the control group.The nodule unit weight after N1 and P1 treatment was the highest,which was 4.49 times and 5.43 times of the control group,respectively.The hemoglobin content of nodule beans first increased and then decreased with the increase of N level.The hemoglobin content was 1.96 times of the control group after N2 treatment,but decreased with the increase of P level.The content of glycyrrhizic acid and liquirtin first increased and then decreased with the increase of N level,the content after N2 treatment being the highest.The content of glycyrrhizic acid and liquirtin increased with the P level.Conclusion When Rhizobium solution is used,an appropriate amount of N and P helps promote the accumulation of biomass and active components in Glycyrrhiza uralensis Fisch.,promote the nodulation of Glycyrrhiza uralensis Fisch.,and improve the nitrogen fixation of root nodules.