一个反向水稻两用核不育系育性对温度与光周期的反应

Response of Fertility of a New Reverse P(T) GMS Line to Temperature and Photoperiod in Rice

以水稻两用核不育系go3S为材料,在其育性转换敏感期,用不同光周期与不同温度处理,研究了其育性对光周期与温度的反应.结果表明,在长日高温(30.5℃)与短日高温处理条件下,go3S均表现为可育,自交结实率为40.9%～41.5%,花粉可染率为58.5%～61.4%;而在长日低温(23.5℃)与短日低温处理条件下,go3S均表现为不育,自交结实率与花粉可染率均为0.育性表现在长、短日处理之间无显著差异,但在高、低温处理间存在显著差异,说明go3S育性受温度控制,不受光周期影响,且为高温可育、低温不育型,其育性转换方向与通常的温敏型水稻两用核不育系相反,故go3S为反向温敏型水稻两用核不育系.2005年,在长沙夏季自然条件下,当其育性转换温敏感期遇到平均日均温31.4～31.9℃的高温时,go3S表现为可育,花粉可染率为57.7%～65.0%,自交结实率可达40%以上;而遇到平均自然日均温25.7～26.0℃的较低温度时,则表现为不育,花粉可染率为0.2%～0.7%,自交结实率为0;进一步在其育性转换温敏感期用26.0℃及28.0℃的人工恒温冷水连续处理7 d,go3S也表现不育,花粉可染率为0～0.8%,自交结实率为0,说明go3S育性转换的临界温度界于28.0～30.5℃之间.

The responses of fertility of go3S,a new P（T）GMS line,to photoperiod and temperature are studied in rice（Oryza sativa L.） by treatment with different photoperiods and different temperature at its fertility alternation sensitive stages.The results show that the fertilities of go3S are fertile with bagged seed set of 40.9%～41.5% and stainable pollen grains of 58.5%～61.4% when it is treated with short day（SD） or long day（LD） for 15 days at its photoperiod sensitive stages related to fertility alternation under natural high temperature（HT,average daily mean temperature of 30.5 ℃）,but sterile with bagged seed set and stainable pollen grains of zero when treat with above photoperiod conditions（SD or LD for 15 days） and the same fertility alternation sensitive stages under artificial low temperature（LT） of 23.5 ℃.Therefore,there is no significant difference for fertility phenotypes of go3S between SD and LD conditions,but the significant difference is found between HT and LT conditions.So the male fertility of go3S is not controlled by photoperiod but temperature,and the direction of its male fertility alternation is opposite to that of the conventional T（P）GMS lines,i.e.,abortive under low temperature,but fertile under high temperature.Based on above results,it is concluded that go3S is a new reverse TGMS line in rice.To detect its critical temperature（CT） inducing male fertility alternation,the fertility responses are checked under different temperature conditions at its thermo-sensitive stages related to fertility alternation.In summer,2005,it was fertile with stainable pollen grains of 57.7%～65.0% and selfed seed set of above 40% when it met average daily mean temperature of 31.4～31.9 ℃ at its thermo-sensitive stages in Changsha,Hunan province.However,it was sterile with stainable pollen grains of 0.2%～0.7% and selfed seed set of zero when it met average daily mean temperature of 25.7～26.0 ℃.Furthermore,when treated with 26.0 ℃ or 28.0 ℃ for consecutive 7 days by controlled temperature water（water depth 20 cm about） at the same thermo-sensitive stages,it was sterile either with stainable pollen grains of 0～0.8% and selfed seed set of zero.From those results,it is deduced that the CT of go3S ranges from 28.0 ℃ to 30.5 ℃.