几种生态因素对西北干旱地区豆科植物结瘤固氮的影响

通过对西北干旱地区栽培和野生豆科植物不同环境条件固氮状况的调查表明，栽培豆科植物一般能自然结瘤，野生豆科植物种的结瘤率极低。根瘤颜色栽培植物多为粉红色，而野生植物多为白色、黄色或棕色。通过对水分、光照强度和温度等不同条件下根瘤ARA测定，表明根瘤固氮活性与生态条件关系密切，而土壤水分是限制根瘤固氮活性表达的主要因素。

Characteristics related to symbiotic nitrogen fixation of legumes in northwest arid zone of China

The nodulation and nitrogen fixation of major cultivated and wild legumes have been studied in northwest arid zone of China. All of cultivated and a few of wild plants can nodulate in nature environment. The shapes of nodules of these plants were circular, ellipse of cudgel, most of cultivated plants were pink and wild were white, yellow and brown in colour. More then 500 samples of nodules were detected with the method of acetylene reduction.25.6%of these nodules were ineffective for nitrogen fixation. The activities of nitrogen fixation in nodules various species of various region of varied greatly and all of them were low. It seems that the nitrogen fixation activity in nodules is related to growth period, living habits, light intensity, soil humidity, plant transportation and toleranced to environmental stress of host plants.