Effect of lower temperature on germination of rice seed originated in different localities.

[摘要] Many vatieties of rice introduced considerably long years ago into Japan, were cultivated under uniform conditions on paddy field of the Mie Agricultural College in 1947 and experiment was taken in thermostat controlled at 15°C and 30°C in January in 1948. Results are as follows. (1)In 30°C-test, germination percentage and speed of all varieties except two originated in India, are very good and there are no difference within varieties and localities originated. So it is clear that seeds used are very good. Cause of bad germiination of two varieties from India are yet unknown. (2) In 15°C-test, varieties having round-shaped kernels (so-called Japonica) are better in germination percentage than those having long-shaped kenels (so-called Indica). Among the former, Japanese water rice, Japanese hill rice and Korean varieties are the best. Among the latter, Indian varieties are the worst. But mean germination speed of Japanese hill rice and Korean varieties are more rapid than Japanese water rice varieties. (3) As the results of the present observation, it will be probably said that difference of germination under lower temperature may be based rather on ecological difference due to localities than on each varietal difference. Also it may be said that the germinating capacity under lower temperature will not disappear in many years since importation to other country and that it will be considered as a fixed race character.

[学科分类] 农业科学（综合）