玉米光周期反应的敏感时期研究

Study on Sensitive Period of Maize in Photoperiod

采用长日照15 h、短日照9 h和长短日照相互挪移处理玉米自交系黄早4和CML288,利用激光扫描共聚焦显微镜观察了玉米茎尖的形态变化,调查了玉米的主茎叶片数、抽雄散粉期和吐丝期等主要生育性状。结果表明,短日照能促进玉米茎端分生组织向生殖生长转化,促进开花,减少玉米的主茎叶片数,缩短玉米的生育期,而长日照则相反;当从短日照挪移到长日照时,黄早4在第五和第六片展开叶之间、CML288在第六和第七片展开叶之间的挪移,玉米的主茎叶片数突然减少,同时在短日照条件下黄早4和CML288的茎端分生组织也分别在第五和第六片展开叶、第六和第七片展开叶之间发生了形态变化,茎端生长锥伸长变成圆锥体开始花的发育,而当从长日照挪移到短日照时,玉米的主茎叶片数呈现连续性变化,因此光周期诱导玉米开花的敏感时期因光照条件和品种有一定差异,长日照条件下玉米的光周期反应不敏感,短日照条件下光周期诱导的敏感时期黄早4在第五和第六片展开叶之间,CML288在第六和第七片展开叶之间。

2 maize inbred lines,Huangzao 4 and CML288,were treated with long-day 15 h,short-day 9 h,and alternative long-day and short-day to study the sensitive period of maize.The stem tips were observed by Laser Scanning Confocal Microscope,and the number of leaves,tasselling stage,powder stage,silking stage was recorded.The results showed that short-day could promote maize flowering,decrease the number of maize leaves and shorten growth duration;while the effect of long-day was the opposite.While transferred from short-day to long-day,the number of leaves suddenly decreased between No.5 and 6 leaf of Huangzao 4 and between No.6 and 7 leaf of CML288.At the same stage,under the short-day condition,maize apical meristem elongated and flower development phase began.But,while transferred from long-day to short-day,the number of maize leaves had a continuously change indicating that there was an obviously variance among sorts of maize under different photoperiod condition.Maize photoperiod reaction was insensitive to the long-day condition.Under the short-day condition,the sensitive period of Huangzao 4 and CML288 in photoperiod was between No.5 and 6 leaves and between No.6 and 7 leaves,respectively.