The results indicated that the roots of nodules legume plants are soft and tint in color, whereas the roots of no-nodules legume plants are firm and fuscous.

• 结果表明，结瘤豆科植物的根系松软，颜色较浅，为白色或土黄色；不能结瘤的植物根系坚硬，颜色较深，为黑色或深褐色。