荧光素钠在香子兰生活胚珠中的运输  

TRANSLOCATION OF URANIN WITHIN THE LIVING OVULES OF VANILLA

作　　者：张振珏[1] 郑国基[1] 

机构地区：[1]福建省亚热带植物研究所

出　　处：《Acta Botanica Sinica》1988年第5期490-493,共4页Acta Botanica Sinica（植物学报：英文版）

摘　　要：在香子兰(Vanilla planifolia Andr.)未受精的胚珠中,外珠被只包到胚珠的下半部。荧光素钠自珠柄进入胚珠,先在胚珠合点区形成一个荧光中心,然后沿内珠被向珠孔端运输,在内珠被的珠孔端形成第二个荧光中心。不久卵器中显现荧光。受精以后,胚珠的外珠被向上延伸,与内珠被共同形成珠孔。荧光素钠经珠柄进入后向几个方向扩展:1.运至珠孔口处的外珠被中,2.沿珠柄一侧的外珠被向下至合点区;3.由合点区分别向内部和向远离珠柄一侧的外珠被扩展。香子兰胚珠中不具维管束,不过荧光素钠在内珠被中运输时,明显可见紧贴胚囊的内层细胞是其主要运输通道。胚囊成熟时,珠孔端一半在内珠被与胚囊之间有角质层相隔,胚囊合点端的一半与珠心细胞间无角质层,营养物质无疑可由合点端进入胚囊。但是卵器是在内珠被珠孔端荧光中心形成后才出现荧光的,不能排除营养物质自珠孔端进入胚囊的可能性。In the ovules of Vanilla(Vanilla planifolia Andr.)before fertilization,outer integume- nt surrounded the lower part of ovule.Uranin got into ovule through funiculus,forming the first center of fluorescence at the chalaza zone of ovule.Then uranin was transported to micropyle end along inner integument,forming the second center of fluorescence at micro- pyle end of inner integument.Soon,fluorescence appeated in the egg apparatus. After fertilization,the outer integument of ovule extended upward,forming micropyle logether with inner integument.After getting into ovule through funiculus,uranin spreads to- ward several directions:1.transported to outer integument at the entrance of micropyle;2. transported downward to chalaza zone along outer integument at the side of funiculus:3.ex- tended from chalaza zone to the inside and to the outer integument at the side far from funi- culns.The ovules of Vanilla had no vascular bundles.On transporting in inner integument, however,the cells in inner layer next to the embryo sac appeared to be the major passage. In mature embryo sac,there was cuticle between inner integument and embryo sac at the half of micropyle end.But between embryo sac at the half of chalaza end and nucellus,cuticle was absent.Nutrient could get into embryo sac from chalaza end undoubtedly.As egg appara- tus showed the fluorescence after formation of fluorescence center of inner integument at mi- cropylar end,the possibility that nutrient got into embryo sac from micropyle could not be ex- cluded.

关 键 词：香子兰 生活胚珠 荧光素钠 运输 营养物质 内珠被 胚囊 

分 类 号：Q949.718.4[生物学—植物学]