Abstract
There are several mutant strains of which are unable to elongate only the 2nd internode counted below from upper position of culm in rice plants.
These mutant strains, Murasakidaikoku, Daikoku No. 1 and Daikoku No.4 etc., are all the dwarf rice plants.
It was found that the length of abnormal 2nd internode was controlled by a single recessive gene from the results of normal elongation of the 2nd internode in F1 plants and segregation ratio of F2 generation.
By controlling photoperiod and temperature condition, elongation of the heritable abnormal internode was induced as that of the 2nd internode in normal rice plant.
That is, the abnormal 2nd internode elongated under 10 hr day length and at 30°C day and 27°C night temperature condition, on the other hand the internode did not elongate under 14 hr day length and at 25°C day and 18°C night temperature condition.
Low nitrogen level in culture solution brought about the elongation of the abnormal 2nd internode as compared with high nitrogen level.
