Intensity of Guttation in Rice Seedlings in Relation to Earliness or Lateness of the Variety

We are investigating the differences in physiological properties of seedlings of rice varieties differing in their time of maturation. In our previous studies on the respiration of root of rice seedlings, the superiority of root activity of late maturing varieties over that of early maturing varieties was recognized. In this experiment the difference in the guttation and bleeding of seedlings of various varieties were examined. 1. The guttation increased in parallel with the lateness of varieties, i. e. late maturihg varieties showed always greater amount than earlier ones. The rate of guttation was as follows: in early maturing varieties, 100; in the medium, 121.1 and in the late, 159.8. 2. When rice seedlings were cultured in different concentrations of distilled water solution of sucrose, we confirmed that the guttation of early maturing varieties was always inferior to that of the late ones. Therefore the osmotic pressure of the roots of earlier maturing varieties seemed to be lower than that of late ones. 3. In bleeding also we could perceive the same tendency as in guttation.