粳型光温敏感雄性核不育系开花习性研究

Study on the flowering habit of P(T)GMS lines of japonica rice

对2个粳型光温敏感雄性核不育系和3个其他水稻材料进行了栽培试验。结果表明:温度在28℃以上,湿度在51.5%～86.0%,参试材料均能正常开花,最适宜开花环境为:温度31.3～33.2℃,湿度51.5%～55.8%。粳型二系不育系有4个开花高峰,开花数量各占全天开花量的26.2%、32.0%、32.9%、8.9%,呈现出开花高峰多、开花过程时间长的特点。籼型恢复系‘浦恢22'开花集中,开花量大,全天有2个开花高峰,开花量占全天开花量的%.1%,开花时间早于粳型二系不育系,花时差达50～80 min;在制种中只能以第2开花高峰37.8%的开花量与粳型二系不育系相遇,影响制种产量。因此,选育花时早而集中、异交率高的粳型不育系,成为粳籼亚种间杂交选育超高产杂粳组合、提高制种产量和大面积推广的关键。

The cultural experiments with two japonica-type P（T） GMS lines and three other rice materials were carried out to observe their flowering habits. The results showed that all the test mate- rials could flower normally when the temperature was above 28℃ and the humidity was 51.5% - 86.0% ,and the best flowering conditions were 31.3 - 33.2 ℃ and 51.5% - 55.8% humidity. The P （T） GMS lines had four flowering peaks, and their flowering numbers accounted for respectively 26.2% ,32.0%,32.9% and 8.9% of the full-day flowering number, being characterized by multiple flowering peaks and long flowering duration. The Indica-type restorer ＇Puhui 22 ~ had two flowering peaks whose flowering number accounted for 96.1% of the full-day flowering number, and its flower- ing time was 50- 80 min earlier than the P（T） GMS lines＇. Only the 2nd flowering peak of ＇Puhui 22＇ which contained 37.8% of the whole flowering number could meet the P（T） GMS lines,thus affecting the production of hybrid seeds. Therefore selecting japonica-type P（T） GMS lines that flower early and concentratedly and have a high outcrossing rate is the key to cross breeding between Indica-type and japonica-type subspecies so as to improve the production of hybrid seeds and largely popularize In- dica-japonica hybrid rice production.