Studies on the physiology of bolting and flowering in Raphanus sativus L. II Annual rhythm in readiness to flower in Japanese radish, cultivar 'Wase-shijunichi'

Flowering of Raphanus sativus L. (Japanese radish, cultivar‘Wase-shijunichi’) is hastened by vernalizationbut non-vernalized radish could flower under continuous illumination.Days from germination to anthesis in non-vernalized plants fluctuateddepending on the period of seed storage, and this fluctuationshowed an annual rhythm. On the contrary, the days to anthesisin vernalized radish remained nearly constant for 2 years. ¹Present address: Department of Horticulture. Gangweon NationalUniversity, Chuncheon 200, Korea. (Received November 25, 1975; )