There are many genes which control the flowering development. FLORICAULA/LEAFY gene is one of controlling flower meristem identity of plant. We isolated the homologue gene (DFL) of FLORICAULA/LEAFY from D. lavandulifolium. The genomic sequence of DFL include three extron and two intron. The number and position of introns are conserved with other most FLORICAULA/LEAFY homologue. This result is helpful for better understanding the mechanisms of plant flowering and may have important effect in the forestry and angriculture.
利用常规研究方法,对甜菜单体附加系M 14品系(B eta vu lg aris L.,VV+1C、2n=18+1)的生殖方式进行细胞学与胚胎学研究.结果表明:(1)甜菜单体附加系M 14的4代细胞学检查表明:染色体组分别为VV+1C、2n=18+1;VV+0、2n=18+0;VV+2C、2n=18+2;VVV+0、2n=27+0;VVV+1C、2n=27+1;VVV+2C、2n=27+2等,其中VV+1C、2n=18+1的植株传递率平均为96.7%,表现为稳定传递,具有二倍体孢子无融合生殖特性;其余各种分离植株的传递率总计为3.25%,有性生殖发生率较低.(2)胚胎学研究表明,二倍体孢子无融合生殖的胚珠中,珠孔处看不到花粉管,胚囊没有发生受精作用.2个助细胞提前退化,半数卵细胞的极性与正常卵细胞相反;卵与次生核不经受精而自发分裂,卵细胞自发分裂产生无性胚,次生核自发分裂产生核型胚乳,而且次生核自发分裂早于卵细胞分裂;有性生殖胚珠中,珠孔处可见多条花粉管,胚囊里见到精卵融合的图像.表明甜菜单体附加系M 14是以二倍体孢子无融合生殖为主要繁殖方式,有性生殖为次要敏殖方式的兼性无融合生殖体.
