Abstract:

In order to ascertain the damage mechanism of high temperature stress on rice, two early rice cultivars were treated with different high temperature treatment during heading and flowering period in the controlled environment chamber, flowering characteristics and seed setting were determined. The results showed that, with the increase of temperature treatment, daily number of spikelet flowering and the daily flowering peak value decreased, glume opening angle, anther dehiscence, pollen vigour, stigma vigour decreased, pollen diameter significantly increased, seed setting decreased. According to the correlation analysis, seed setting ratio of two cultivars showed a significantly linear correlation with pollen vigour, anther dehiscence and stigma vigour, respectively. A significantly difference of different high temperature treatment effects on flowering characteristics and seed setting during heading and flowering period existed among different cultivars, high temperature tolerant cultivar 996 was lower than high temperature sensitive cultivar 4628.