濒危植物——长喙毛茛泽泻的受精作用及胚和胚乳的发育  

THE FERTILIZATION AND THE DEVELOPMENT OF EMBRYO AND ENDOSPERM IN AN ENDANGERED PLANT——RANALISMA ROSTRATUM STAPF (ALISMATACEAE)

作　　者：田惠桥[1] 陈家宽[1] 郭友好[1] 

机构地区：[1]武汉大学生物系,武汉430072

出　　处：《植物分类学报》1995年第4期357-361,共5页Acta Phytotaxonomica Sinica

基　　金：国家自然科学基金委重大项目"中国主要濒危植物保护生物学研究"课题;项目编号39391500

摘　　要：长喙毛茛泽泻Ranalisma rostratum Stapf的配子融合开始较早,但精核与极核融合速度较快。精核与珠孔极核融合后即移向胚囊合点端与另一极核再融合形成初生胚乳核。初生胚乳核第一次分裂后形成两个细胞,以后珠孔端胚乳细胞再进行游离核分裂,胚乳发育属于沼生目型。开花后两天,合子分 裂。八分体呈4层,每层呈两个细胞方式排列,胚胎发生属于石竹型。Ranalisma rostratum Stapf is a rare and endangered species. This paper deals with the fertilization and the development of embryo and endosperm in this plant. The em-bryogenesis is of Caryophyllad type and the development of endosperm belongs to Helobial type. Before fertilizaton, the two polar nuclei are located respectively at both ends of embryo sac In most angiosperms with two polar nuclei, the polar nuclei may fuse either before fertilization to form a secondary nucleus or during fertilization called triple fusion. In Ranalisma rostratum Stapf, however, it is found that only in case when the micropylar polar nucleus is fertilized, it can move to the chalazal end and fuse with the chalazal polar nucleus. This phenomenon is very rare and the process must take more time to fulfil fertilization both polar nuclei. This feature of fusion of polar nuclei is therefore thought as a primitive character from the view of phylogeny.

关 键 词：长喙毛茛泽泻 濒危植物 受精作用 胚 胚乳 

分 类 号：Q949.712.5[生物学—植物学]