光温条件对北方粳稻光温敏核不育系LY156S育性转换的影响及其育性鉴定技术探讨

Effects of Photoperiod-temperature Conditions on Fertility Alteration of Northern China Japonica PTGMS Line LY156S and Discussion of Its Fertility Identification Technique

通过对不育系应用区域气象条件的分析,选择不同光温条件处理北方粳稻光温敏核不育系LY156S,研究光温变化对其育性转换的影响及育性鉴定方法。结果表明,在不育系制种区域辽宁盘锦,2011—2017年的7—8月日平均温度大于23℃,最低温度为20℃,低于23℃的天数较少,适合临界温度为21℃左右的两系不育系制种;在不育系繁殖地区海南三亚,2011—2017年冬季低于20℃天数较少,且比较分散,较适合两系不育系繁种。在长日照14.5h低温处理下,不育系的抽穗期滞后,22和21℃处理下育性没有恢复,但20和19℃处理花粉不育度降低到82.36%和78.45%,育性发生了转换。在日照长度为11.5和12.5 h条件下,22和24℃处理的育性均得到恢复;在日照长度为13.5 h条件下22和24℃处理的花粉不育度仍都大于99.5%,育性没有恢复。为提高北方粳稻光温敏核不育系应用的安全性,北方粳稻光温敏核不育系育性鉴定在《水稻光、温敏雄性核不育系育性鉴定规程》(NY/T 1215—2006)的基础上,可将14.5 h长日照条件下的处理温度降至21℃,11.5、12.5和13.5 h等短日照条件下的处理温度降低至22℃,以提高不育系的育性鉴定准确性与应用价值。

The meteorological conditions were analyzed in the application area of PTGMS lines.The photoperiodtemperature treatments were conducted on the photo-thermo-sensitive genic male sterile(PTGMS)northern China japonica line LY156 S under the artificially-controlled conditions to study the effects of photoperiod-temperature conditions on fertility alteration and the fertility identification method of PTGMS lines.The results showed that the averaged daily mean temperature was above 23℃with the minimum temperature at 20℃and few days below 23℃from July to August during 2011 and 2017 in the hybrid rice seed production area of Panjin,Liaoning,so it is suitable for twoline hybrid seed production of PTGMS lines with a critical temperature at about 21℃.There were few scatteredly distributed days with daily mean temperature below 20℃from January to February during 2011 and 2017 in Sanya,Hainan,so it is suitable for the multiplication of PTGMS lines.Under the conditions of long daylength(14.5 h)and low temperatures,the heading stage was delayed,the pollen sterility of 22℃and 21℃treatments was over 99.5%,showing no obvious effect on fertility alteration,the pollen sterility of 20℃and 19℃treatments was 82.36%and 78.45%,indicating the fertility alteration occurred.Under the conditions of daylength at 11.5 and 12.5 h,the fertility was recovered for the treatments of 22℃and 24℃,while under the conditions of daylength at 13.5 h,the pollen sterility was still over 99.5%so the fertility was not recovered for the treatments of 22℃and 24℃.To ensure the application safety of PTGMS lines in northern China,on the basis of the'Fertility evaluation protocol of environmental sensitive genic male sterile(EGMS)line of rice'(NY/T 1215—2006),the treating temperature should be decreased to 21℃under the long daylength of 14.5 h,and decreased to 22℃under the short daylength of 11.5,12.5,and 13.5 h in the fertility identification of northern China japonica PTGMS lines so as to improve the accuracy of fertility identification and the application value of the PTGMS lines.