High temperature-induced sterility in indica rices at flowering

摘要: Response of three typical varieties to high temperature at different stages growth and on flowering day was studied in naturally lighted rooms phytotron.Spikelet sterility induced by largely day. Within the day, during anthesis time most detrimental spikelet fertility, right before being second most. High after had little influence fertility; when spikelets were exposed one hour anthesis, their fertility normal. The major causes temperature-induced attributed disturb pollen shedding decreased viability grains, resulting number germinated grains a stigma. ability pistil be fertilized appeared remain unaffected up 41°C. When for 8 hours critical induce 20% 36.5°C N22, heat tolerant, 32°C BKN6624, susceptible. At 38°C, duration 4 N22 2 BKN6624. 41°C, treatment about 90% all varieties. Dihiscence characteristic anther that allows good early morning avoids considered two important characteristics tolerance rice flowering.