本试验以典型优势的杂交组合为材料，分析了甜菜块根分化形成期（苗期）不同叶龄期叶片中有关呼吸酶、糖分含量和杂种优势的关系。结果表明，ＮＡＤ－苹果酸脱氢酶、过氧化物酶活性和糖分含量，因不同倍性品种存在着明显的差异，与杂种优势有密切关系，可作为早期鉴定和预测的重要参考指标。 In this experiment, we analyzed the relationship between respiration enzyme, sugar content and heterosis in the leaves of different leaf-age stages in the root-forming stage (seedling stage) of beet root tuber. The results showed that NAD-malate dehydrogenase activity, peroxidase activity and sugar content were significantly different from those of different ploidy varieties and were closely related to heterosis. Therefore, NAD-malate dehydrogenase, peroxidase activity and sugar content could be used as important reference indexes for early identification and prediction.