抄録
A research was made on the study of salt injury, and 8 varieties were used to determine their salt resistance. The results obtained were as follows. (1) The upper limit of NaCl concentration that permitted germination was 2.0% for the unhulled grains, while the upper limit that permitted the embryo organs to break rose to 4% for the hulled grains. (2) When the grains were kept in 3% NaCl solution for 7 days, germinated grams had the higher contents of NaCl as 1.15%, but ungerminated grains contained only 0.51% of NaCl. Salt injury was severe at the germinated grains than at the ungerminated ones. (3) Absorption of Cl by the germinated grains was traced by the microdetection of Cl. When the germinated grains grown in the distilled water were placed in 0.3 % NaCl solution, Cl entered into the coleorhiza hairs only in a minute. Cl moved into the base of coleorhiza and scutellum about 3 hours after the accumlation of Cl was found in the vasculer boundles of scutellum, plimule and radicle. After 6 hours, Cl appered in the epitherium layer and at the outside of endosperm. Coleorhiza absorbed Cl very quickly and absorbed Cl seemed to enter into embryo and endosperm from the coleorhiza by the route mentioned above. (4) The varietal differences of salt resistance were examined in the germination of grains in the high concentration of NaCl by the use of 8 varieties. The resistant varieties. Ayanishiki, Hatamurasaki (upland rice), Norin no.9 (upland rice) and Tosan no.38 germinated faster than the no resistant varieties, Norin no.1, Fujisaka no.5 and Hatsushimo. Norin no.18 which was shown to be no resistant variety by the Ota's study (1958) germinated faster than the group of no resistant varieties. The speed of germination by which the coleorhiza breaks the pericarp in the high concentration of NaCl seemed to depend mainly on the water absorption power of varieties under the high osmotic pressure.
