【摘要】 以多年生开花鹤望兰植株为试验材料,采用不同浓度秋水仙素(0.05%,0.10%,0.20%)对鹤望兰处于减数分裂Ⅰ期的幼小花蕾进行诱导。结果表明:0.20%浓度的秋水仙素诱导效果最好。与对照相比,在形态学上,花瓣、萼片、柱头,花粉粒大小等变化较明显。细胞学上,配子出现了明显的加倍现象,并检测到导致2n花粉形成的异常减数分裂现象:(1)中期Ⅱ和后期Ⅱ的小孢子母细胞中发生异常的纺锤体定位,表现为平行、八字形、融合纺锤体;(2)末期Ⅱ4个子核呈两极分布,每极2核,或呈三极分布,其中一极2核,另两极单核;(3)四分体时期观察到了二分体、三分体情况。并且2n花粉频率的估测值(20.30%)与实测值(17.30%)相接近。因纺锤体定位异常而产生的2n配子在遗传上等同于FDR型,因而在有性多倍化育种中具有重要的利用价值。更多还原

【Abstract】 Perenial flowering planrs of Strelitzia reginae are used as material.The First meiosis young flowers are induced with different concentration colchicines(0.05%,0.10%,0.20%).The result shows that on the condition of 0.20% the effects are best.Compare with control experiment.There are obvious differences on morphology from petal,calyx,stigma and pollen grain size and so on.Gametes are polyploided obviously on cytology,and the observed metiotic abnormalities resulting in the 2n pollen production revealed that:(1)disoriented spindles,including parallel,triangle spindles and fused spindles,were formed at metaphase II and anaphase II;(2)the nuclei at telophaseⅡwere arranged in two poles,each pole contained two nuclei,or in three poles,one of which contained two nuclei,the other two contained one nucleus respectively;(3)dyads and triads were produced at the tetrad stage.The estimated frequency of the 2n-pollen(20.30%) agreed with that the fact(17.30%).The 2n pollen produced by this mechanism were genetically equivalent to FDR gametes,and consequently had a potential value for sexual polyploidization.更多还原