高温诱导白杨2n花粉有效处理时期的研究

以毛新杨 (Populustomentosa×P .bolleena)为材料 ,研究了高温诱导花粉染色体加倍与减数分裂始处理时期的相关关系 .试验结果表明 :高温诱导 2n花粉的有效处理时期 (也是相对非敏感时期 )位于终变期到中期Ⅰ之间 ,最高可获得 87 6 %的 2n花粉 ,但花粉量较少 ,同时还发现有连体花粉和疑为四倍性的超大花粉粒存在 .推断 2n花粉的产生除了高温可直接作用于纺锤体等造成染色体不减数外 ,还作用于细胞板的相关功能性机构 ,从而抑制新生细胞壁的形成 ,同样产生花粉染色体加倍效果

Suitable period of high temperature treatment for 2n pollen of Populus tomentosa×P.bolleana

This paper discusses the efficiency of chromosome doubling of pollens from Populus tomentosa×P.bolleana induced by high temperature at different stages of meiosis.It was shown that,during the period between Diakiness and the Metaphase Ⅰ, the highest rate of 2n pollens reached to 87.6%,with smaller amount of live pollens.Meanwhile the occurrences of pollen sticking together or super sized pollen grains of tetraploidy were observed.Therefore the mechanism of the formation of 2n pollens was postulated that high temperature could work directly on spindle and resulted in no separation of chromosome.Another mechanism was that high temperature also worked on functional structures related to cell plate, inhabited the formation of new cell walls,thus made pollen chromosome doubled.