Development of the small-scale accelerated generation advancement method according to processing in artificial photo-thermal treatment

In order to raise the breeding efficiency of a sugar beet we developed the simply small-scale accelerated generation method which is able to reduce the labor and time. As a result of performing about 49 individuals on dense planting conditions in the small bowl of 28cm x 31cm after processing photo-thermal treatment, we attained to make the method which is available to use breeding. Seed can gather after performed by the methods as bellows. 1. The seedling is grown for 40 days in the greenhouse of 25 deg C. 2. Nursing plant length is 10cm or more, and number of leaves is 5 or more. 3. Processing of Photo-thermal treatment is done under 150 to 210 days at 5 deg C and 16 days of the hour. 4. After processing the photo-thermal treatment, making it grow in the long day conditions by the night incandescence light in 25 deg C greenhouse. The effect of processing temperature at 5 deg C promotes bolting and the flowering rate was higher than 2.5 deg C. The bloomed plant was observed within 60 days after photo-thermal treatment. And about 0.5g (per one individual) fruition seed can harvest after ripening period within two month. Moreover, high correlation was accepted between the length of a photo-thermal treatment and the flowering rate. The flowering rate increases in proportion to the length of processing period. Threshold of the length of a photo-thermal treatment for fully blooming were differed among lines. To decide the length of processing period, we examined 9 inbred lines from which origin differs. In conclusion, processing for 150 days was able to gather the seed about 90% for almost all lines, and processing for 210 days was able to gather full seed for all lines. This method can carry out seed gathering constantly in a greenhouse, and the one generation can easily promote for one year. Moreover, this method can gather the seed from 500 individuals in only the area of 1m(2), and it can reduce labor of generation promotion at low cost.