Effect of Heat Stress on Spikelet Degeneration and Grain Filling at Panicle Ini-tiation Period of Rice
Pot experiment was conducted to investigate the effects of heat stress on rice spikelets degeneration and grain filling at panicle initiation stage. A tolerant (Huanghuazhan) and a susceptible (Fengliangyou 6) cultivars were treated in phytotron with high temperature (10:00–15:00, 40℃) and normal temperature (10:00–15:00, 32℃) for one, three, five, seven, and nine days at last leaf emergence stage, with these grown under natural condition as control. The results indicated that the ratio of spikelet de-generation increased greatly with increasing heat-treating time. The ratio of spikelet degeneration of Huanghuazhan increased 45.8% and 62.9% after nine days under high temperature as compared with normal temperature treatment (control), and the ratio of Fengliangyou6 increased 81.7% and 136.1% in the same treatment, showing higher ratio of spikelet degeneration in Fenglian-gyou6 than Huanghuazhan. The pollen activity significantly decreased after one day under high temperature stress, and anther formation significantly inhibited after five days under high temperature stress. Bad anther formation and poor pollen activity un-der heat stress resulting in seed-setting rate significantly decreased. Spikelet length and grain filling of two cultivars decreased due to heat stress effect, resulting in a significant reduction of grain weight, with a larger reduction rate in Fengliangyou 6 than in Huanghuazhan. Grain filling reduced significantly after five days of high temperature treatment. According to the study, heat stress at last leaf emergence stage may sharply decrease rice yield, and corresponding cultivation measures should be strengthened in production.
国家科技期刊平台
NSTL
万方数据
维普
