油菜温敏雄性不育系373S的选育

发现和选育新型光温敏雄性不育材料,有利于深入揭示植物雄性不育的发生机制,丰富油菜杂种优势利用的方法。笔者报道一种新发现的环境敏感雄性不育系373S的选育过程及其育性随温度、日长的变化基本规律。2002年在一个天然雄性不育群体后代中发现1株嵌合不育株,经过连续自交,育成环境敏感不育系373S。2004—2006年在陕西杨凌进行分期播种试验,并进行了温度、光照脉冲处理试验。结果表明:373S是主要对温度敏感的雄性不育系,低温可育而高温不育,开花前2￣9d的平均温度对育性影响显著,而日长对育性影响不明显,花蕾长度约2￣3mm是育性转换的敏感时期。用一系列品种与373S测交,F1均为100%可育,在F2代温敏不育株出现几率很高,可以达到7.1%￣14.6%。进一步精确分析373S光温反应特征、改良其农艺及品质性状、寻找适宜制种生态区的工作正在进行当中。

Development of A Thermo-sensitive Male-Sterile Line 373S in Brassica napus L.

Exploitation and development new thermo and /or photoperiod sensitive male sterile materials will promote the theoretical research on the development of male gametophyte and give more approach for utility of the heterosis of rapeseed.In the present paper,the development and primary characterization of a new thermo-sensitive male-sterile line 373S in Brassica napus L.was reported.A chimerically male sterile rapeseed(Brassica napus L.) was found in the open-pollinated family from a spontaneous male sterile population.After successive selfing from this chimerically male sterile plant,an environment-sensitive male-sterile line 373S was bred.The influence of ecological factors on the male fertility was analyzed based on the data from cultivation experiment conducted in field and under controlled conditions.Atmospheric temperature 2~9 days prior to blooming had a predominate effect on the male fertility but the effect of daylength on it was not notable.The sensitive stage was further narrowed at the time when the bud was 2-3mm long(meiotic to uni-nucleic stage of microspore development).Therefore,373S was characterized as a thermo-sensitive male sterile line and would become male sterile at higher temperature but render fertile at lower temperature.The F1 generations of the crosses of 373S with various varieties was observed to be 100% male fertile,and in the F2 generations,7.1%~14.6% plants was thermo-sensitive male sterile.The accurately characterization of the reaction to ecological factors,improvement of the agronomic traits and quality of 373S,search of the suitable region for hybrid production was under way.