Character Expression of Induced Dwarf Mutants in Rice II. Morphological and Histological Observations on the Effects of Temperature on Culm Elongation in the Dwarf Mutant, Fukei No.71.

Following previous studies (KITANO and FUTSUHARA 1981), the effects of temperature on culm elongation of the dwarf mutant, Fukei N0.71 and its original cultivar, Fujiminori were evaluated in the present investigation under eight different tempeature conditions cornposed of the combination of two temperatures, high (30°C-25°C) and low (23°C-18°C), and three growth periods (vegetative, early reproductive, and late reproductive or culm elongation stage). Fukei N0.71 showed a larger response to the treatments in culm elongation than Fujiminori, the culm elongation of the former being reduced significantly by high temperature treatment in the culm elongation stage. On the other hand, under low temperature conditions in this stage, it grew as tall as Fujiminori. To elucidate the dwarfing mechanism of Fukei N0.71, some histological observations were carried out on the elongated internodes of Fukei No.71 and Fujiminori grown under high and low temperature conditions. When Fukei No.71 was grown under high temperature, it showed a tendency for a decrease in the number of parenchyma cells in the longitudinal direction and an increase in number in the transverse direction of each elongated internode. It was also observed that partially non-uniform parenchyma cells occurred only in Fukei No.71 when treated with high temperature. These results suggest that the dwarfness expressed under high temperature condition in Fukei N0.71 is induced by abnormal cell differentiation from intercalary meristems of the internodes.

[1]  O. Kamijima.  Consideration on the Mechanism of Expression of Dwarf Genes in Rice Plants. II. The Actions of Dwarf Genes on Cell Division and Cell Elongation in Parenchyma of Internode. , 1981 .

[2]  H. Kitano,et al.  Character Expression of Induced Dwarf Mutants in Rice. : I. Effects of Temperature on Culm Elongation in the Dwarf Mutant Line, Fukei No 71 , 1981 .

[3]  D. T. Canvin,et al.  Cytological and histological changes induced by cold temperature in the young shoots of Marquillo × Kenya Farmer wheat dwarf 1 , 1972 .

[4]  J. M. Westerman.  Genotype-environment interaction and developmental regulation in Arabidopsis thaliana III. Inbred lines; analysis of response to photoperiod , 1971, Heredity.

[5]  J. M. Westerman.  Genotype-environment interaction and developmental regulation in Arabidopsis thaliana II. Inbred lines; analysis , 1970, Heredity.

[6]  G. Stebbins,et al.  The Morphogenetic Effects of the Hooded Gene in Barley II. Cytological and Environmental Factors Affecting Gene Expression. , 1969, Genetics.

[7]  K. Wada,et al.  Studies on Morphogenesis in Rice Plants. : 3. Interrelation of the growth among leaves, panicle and internodes, and a histological observation on the meristem of culm. , 1968 .

[8]  R. Allan,et al.  Culm Length and Differential Development of Three Foliar Leaves of Near-Isogenic Wheat Lines 1 , 1966 .

[9]  R. Allan,et al.  Culm Length and Differential Development of the Coleoptile, Root, and Subcrown Internode of Near‐Isogenic Wheat Lines 1 , 1966 .

[10]  C. Gorter.  Dwarfism of Peas and the Action of Gibberellic acid , 1961 .

[11]  B. M. Pollock.  Temperature Control of Physiological Dwarfing in Peach Seedlings , 1959, Nature.

[12]  A. Hansen.  The expression of the gene dwarf-1 during the development of the seedling shoot in maize. , 1957 .