Studies on Flowering Habit and Hybrid Seed Set of Rice TGMS Line 96-5-2S with Double Low Critical Temperature Values

The flowering period of rice TGMS line 9652S with dlouble low critical temperature values is 14 days, and the concentrated period is 7 days. Its concentrated flowering time in a day is from 09:30～12:00 on fine day with high temperature and from 11:00～13:30 on cloudy day with low temperature. The flowering spikelet rate before 12:00 on a flowering day is 64.5%. Its flowering habit is similar to that of rice TGMS line Pei'ai 64S. On cloudy day with low temperature, the flowering spikelet rate before 12:00 on a flowering day of 9652S is a little higher than that of Pei'ai 64S,but is a little lower than that of Pei'ai 64S on a fine day with high temperature. The hybrid seed set rate of 9652S pollinated with restorer variety 9311 is 35.3% when meeting long time low temperature and rain at its heading stage, and is higher than that of Pei'ai 64S pollinated with the same restorer variety with net adding percentage of 10.5. It showed application value in the fufure.