ダイコンの採種のための春化処理

Abstract

Effects of vernalization in Raphanus sativus L. cv. Harumaki-Minowase were studied. Early flowering and vigorous growth of the plant were observed in the low temperature treatment at 3°C for 2 or 3 weeks followed by incubation at 15 or 25°C. Days to flowering after low temperature were around 50, irrespective of the different conditions.Plants incubated at 3°C for 2 weeks were planted in the field during the period of March through November. They flowered and seeded, except the ones treated with low temperature in August and November. Days to flowering after planting were from around 24 days with the May-, June-and July-treatments to 96 days with the October-treatment. On the other hand, the largest number of flowers was obtained with the April-treatment, and flowering dramatically decreased with the October treatment. The number of seeds with the June- and July-treatments was 2-3 per capsule, but it was 5 in other treatments.Plants pre-incubated at 3°C for 2 weeks followed by planting in the field under summer conditions were not devernalized, but they were devernalized by 35°C after 3°C pre-incubation for 2 weeks. When the 3°C treatment was prolonged for 3 weeks, they were not devernalized. From these results, effective treatment for vernalization of ‘Harumaki-Minowase’ radish was 3°C for 2 or 3 weeks.