1979 Volume 48 Issue 1 Pages 148-154
Physiological factors associated with the decreasing of lodging resistance of the plants at booting stage due to submersion were discussed. Apparent photosynthetic ability, respiratory ability and the chlorophyll, protein, phosphorus and potassium content of the plant were studied as physiological factors. 1. Under submersion, the apparent photosynthetic rate of the leaf blade, leaf sheath and internode were immediately decreased. 2. The chlorophyll contents of leaf blade were more or less similar in the submerged and the control plants, but those of sheaths of the 14 th and 15 th leaves were higher in the submerged plants. But the same was lesser in all the internodes of submerged plants. 3. The respiratory rate of the leaf blade and sheath was comparatively smaller in the submerged plants than the control ones. But the same was higher in the elongated internodes of submerged plants. 4. The protein content in the leaf blade, leaf sheath and internode, as a whole decreased abruptly in the submerged plants. 5. The soluble phosphorus and potassium content seemed to be unchanged in leaf blade and leaf sheath of the submerged and the control plants. It was, however, in large quantity in the elongated internode of the submerged plants. In the elongated internodes high rate of respiration and cell elongation were observed and these might have resulted due to accumulation of soluble phosphorus and potassium in large quantities.
