Studies on the Plasmolysis Form

Abstract

1. According to the condition of the health, the bulbs of Allium cepa are classified in three groups: A, B and C. Those belonging to class A are most healthy, and show the normal concave and convex plasmolysis. Those of class C are most unhealthy and apt to show the tonoplast plasmolysis. Those of class B occupy intermediate situations in these respects.2. The tonoplast plasmolysis, which appears in Allium cepa, is classified according to its etiology. Generally the occurrence of the plasmolysis of this form is fundamentally due to the fact that the intrability of the cytoplasm increases, while the semipermeability of the tonoplast is maintained unaltered. The increased adhesion between the cytoplasm and cell membrane further facilitates its occurrence.3. There are at least three ways through which cap plasmolysis results. The characteristics of the protuberance are described in detail and its relation to the cap formation is discussed.4. Successive stages in the plasmolysis in Allium cepa, caused with saccharose, KCl and CaCl2 solution, are followed extending through several hours. The plasmolysis proceeds differently according to the kinds of the plasmolyticum as well as to the conditions of the material.5. A preliminary water immersion of the material influences the plasmolysis form. In Allium cepa this influence is not so remark-able in the case of the healthy material as in the case of the unhealthy one, The tonoplast plasmolysis, which is very common to occur in the unhealthy material in a KCI solution is easily avoidable by the immersion in tap water for a length of time, even so short as 30 seconds, which gives rise to the increase of the frequency of concave plasmolysis.6. In Rhoeo discolor the influence of the water immersion, contrary to that observed in Allium cepa, increases the occurrence of the concave plasmolysis in a saccharose solution.7. In Allium cepa and Helodea denasa, the drying of tissue makes the plasmolytic separation difficult, and facilitates the occurrence of the tonoplast plasmolysis. A subsequent water immersion is effective in avoiding this abnormal tendency of the plasmolysis. In Rhoeo discolor a contrary result is obtained also in this respect and the drying increases the convex plasmolysis.8. The cells of the ligule or auricule in Oryza sativa are plasmolyzed with a 0, 5 mol KCl solution. The paddy rice has the tendency to show concave plasmolysis and the upland rice convex plasmolysis. The soil moisture shows a quick and remarkable influence on the plasmolysis form of these cells. When the soil is dry, the concave plasmolysis increases and the plasmolytic separation is rendered difficult. The same tendency appears also after the plant is in the ear.9. The subepidermal cells of the hypocotyl of Linum usitatissimum (flax) are plasmolyzed with a 0, 5 mol saccharose solution. The variety Minami, which is resistant to the wilt disease caused by Fusarium Lini, shows a more remarkable tendency to convex plasmolysis in comparison with several susceptible varieties, including the variety Riga from which the variety Minami has originated.10. Also in the case of the flax the same relation between the soil moisture and the plasmolysis form is perceivable as in the rice plant. By a sufficient water supply the normal convex plasmolysis is recovered from the tendencies toward difficult plasmolytic separation and toward concave plasmolysis which are caused by the drying of the soil.11. In the flax seedling the frequency of concave plasmolysis increases according to the age. A remarkable difference is visible even in a disparity of only a few days in age.12. Among the strains of wheat a difference of the tendency of the plasmolysis form is visible.