マメ科作物の根群形成に関する研究 : 第8報 主根における第2次肥大生長とその3つのタイプについて

抄録

1. In the present study, differences in secondary thickening growth of the main roots were observed using sixteen species. The soil was uniformly prepared and seeds were sown at l.5cm depth. 2. Table 1 gives the diameter of the main roots at 5cm intervals from the base of the root measured at various stages of their growth. From the data, it appears that the activity of the secondary growth is greatest at the base and least near the root tip of the root. The degree of secondary thickening growth varied according to the species; from 20 to 5 mm at the base of the main root. 3. The form of the main roots in the final growth stage are shown in figures 1 and 2. In some species (type A), secondary thickening growth extended to the whole length of the root, in others (type B), thickening occured mainly at the base of the root, whilst in type C there was little thickening from the base to the tip. 4. From these data the main roots have been divided into the following three types: A. Extensive thickening growth type (or Alfalfa type) B. Basal thickening growth type (Soy bean type) C. Little thickening growth type (pea type)