低温时长对粳型光温敏核不育系GB028S育性转换的影响

Effect of Low Temperature Duration on Fertility Alteration of Japonica PTGMS GB028S

用20℃的低温对GB028S分别处理1,3,5,7d,研究不同低温时长对粳型光温敏核不育系育性转换的影响。结果表明:低温使各处理抽穗期滞后2～8d。1d和3d的低温处理下,GB028S花粉不育度大于99.5%,育性没有转换;5d和7d的低温处理下,GB028S的花粉不育度为98.33%和94.33%,自交结实率为2.64%和5.04%,育性恢复。GB028S的临界温度接近20℃,其低温敏感时期的辨别标准为剑叶叶枕距-3～1cm。

The fertility alteration of GB028S, a japonica photo-thermo-sensitive genic male sterile （PTGMS） line was studied at 20℃low temperature for ld, 3d, $d and 7d. Low temperature caused heading stage lag for 2-8d. Pollen sterility of ld and 3d was more than 99.5%, so low temperature of ld and 3d had no effect on fertility of GB028S. Pollen sterility of 5d and 7d was 98.33% and 94.33%, bagged seed set of them was 2.64% and 5.04%. The low temperature of 5d and 7d not only decreased remarkably pollen sterility but also induced some extent of self fertility. The critical temperature was nearly 20~C for GB028S. The most sensitive stage of temperature on fertility alteration was that rice was that rice was at -3-1cm of UPI（upmost pulvinus interval, i.e., the length from the pulvinus of the 2nd leaf from the top to that of flag leaf）.