1964 Volume 32 Issue 4 Pages 353-357
This paper deals with the comparative studies on the tolerance against excess-moisture injury between italian ryegrass and oats from a viewpoint of the ventilating system. The results obtained are as follows : (1) Italian ryegrass is equipped with a well-developed ventilating system, and is able to adapt itself to an over-moist condition by reforming the organization so as to transport air from the top to the roots where molecular oxygen is needed for respiration. (2) Being equipped with a feebly-developed ventilating system through which molecular oxygen m ay not be transported freely from the top to the roots, oats is week in the tolerance against excess-moisture injury. EXPLANATION of FIGURES Figures are drawn diagramatically. The dotted portion in the figures refers to the intercellular spaces containing much air or the tissue having those spaces. The abbreviations are as follows: as, air space; ca, cavity; co, cortex; en, endodermis; ep, epidermis; hy, hypodermis; pa, partition; pe, pericycle ; pi, pith ; rh, root hair ; rv, reinforced vascular bundle ; st, stele ; sv, separated vascular bundle; vb, vascular bundle. Fig. 1. Middle portion of the leaf-sheath of italian ryegrass. Fig. 2. Middle portion of the leaf-sheath of oats. Fig. 3. The node where the leaf-heath is going to depart from the stem of italian ryegrass. Fig. 4. The same sapect as above of oats. Fig. 5. The internode of italian ryegrass. Fig. 6. The internode of oats. Fig. 7. The root-zone with a fully-develoqed crown root of italian ryegrass. Fig. 8. The aspect as above of oats. Fig. 9. Basal portion of the root of italian ryegrass. Fig. 10. Basal portion of the root of oats. Fig. 11. Middle portion of the root of italian ryegrass. Fig. 12. Middle portion of the root of oats. Fig. 13. Apical portion of the root of italian ryegrass. Fig. 14. Apical portion of the root of oats.
