Studies on the Salt Injury in Rice Plant : VIII On the occurrence of deformation in the flower

[摘要] Deformation in rice flowers has hitherto been known to be induced by drought, hideri-aodachi (straighthead), cool weather, submergence of the plant, conversion of the field from upland to paddy conditions, deterioration of soil, or even by mutation. The authors found the fact that the same phenomenon would be caused by the salt injury. The rice variety "Kyoto-asahi" was sown on July 13, in 1954 (later than the ordinary sowing time), and was grown in pots by sand-culture with the Nacl solution of various concentrations. In plots of both 0% (control plot) and 0.1% salt concentration, the heading was started on Sept. 21st and continued up to the middle of Oct. after that some panicles stopped however to emerge out of the leaf sheath, and no deformed flower was found on the plot. In plot of 0.3% salt concentration, however, the heading was delayed by 3 or 4 days compared with that in the control plot, and deformed flowers were observed in all panicles. Illustrations of a panicle and flowers are shown in Figs. 1 and 2. These flowers can be classified as follows: (0) Normal flowers (1) Flowers with gigantic or abnormal glumes (2) Flowers with beak-formed lemma or abnormal glumes (3) Flowers with small and abnormally developed glumes (4) Flowers with small and extremely abnormal glumes (5) Flowers with degenerating palea, or lacking in palea (6) Flowers with many small glumes (7) Flowers similar to (5) and (6) but extremely small (8) Flowers with either lemma and palea degenerating or lacking in glumes (9) Flowers scarcely developed Abnormal flowers rather appeared few in the panicle which headed early, and the later the panicles headed, the more and the severe was the deformity. On the other hand, in the case of the plot that was sown on the usualy time, that is, May 27th even in plot of 0.3% of salt concentration (the headint time was from 6th to 16th Sept.), no deformity was found at all. It can be presumed, from this fact, that occurrence of deformity might be due to the harmful effect of low temperatures at the critical stages of panicle development and heading, in addition to salt injury.

[学科分类] 农业科学（综合）