抄録
The experiment dealts with the growth and morphology of callus in various varieties of rice belonging to Japonica and Indica types. The result indicates that Te-Tep has the highest growth rate among fifteen varieties used, reaching 3.13 g/5 seeds in fresh weight in 30 days at 30°C (table 2). There was observed the friable or compact callus (figs. 1 to 15). Te-Tep grows to the most compact callus, and Konan-senhas the highest growth rate among friable callus. According to an estimation of the diameter of nuclei with 100 cells of each callus, they indicates 6.3μ to 7.5μ wide in average value (table 3). It call be said that the nature of callus, friable or compact, growth rate, and size of the nuclei are independent to the types of variety, Japonica or Indica. It is interesting that the giant nuclei over 11.0μ appeared at a rate of 0.5 per cent of all nuclei observed. 5.5μ to 7.4μ of nuclei were 60.5 per cent. It was also observed that callus initiation and development in solutions of various concentrations of 2, 4-dichlorophenoxyacetic acid were different according to the varieties used, exception for Vialone nano which did not initiate callus at all at 1μM of 2, 4-D (table 1).
