宽叶吊石苣苔的胚胎学研究及其系统学意义

观察和记录了较完整的宽叶吊石苣苔 ( Lysionotus pauciflorusvar.latifolius)胚胎学发育过程 ,其花药有四个小孢子囊 ,绒毡层属分泌型 ,花药壁的发育属双子叶型 ,小孢子母细胞胞质分裂为同时型 ,具四面体型的四分体 ,花粉二细胞型 ;孢原细胞直接发育为大孢子母细胞 ,四分体直列式 ,倒生胚珠 ,单珠被 ,薄珠心 ,蓼型胚囊 ;珠孔受精 ,细胞型胚乳 ,具细长的 2核单胞合点端吸器和 2个单核细胞珠孔端吸器 ;胚胎发育为柳叶菜型 .分析表明 ,苦苣苔科胚胎学特征与玄参科 ( Scrophulariaceae)、列当科 ( Orobanchaceae)和爵床科 ( Acanthaceae)较为相似 ,反映了系统学上的相近性

Embryology of Lysionotus pauciflorus var. latifolius and its systematic significance

Embryology of \%Lysionotus pauciflorus var latifolius\% has been studied in this paper. There are 4 microspore sacs in each anther. The tapetum is of secretory type. Development of anther wall belongs to dicotyledon type. Cytokinesis of microspore mother cell is of simultaneous type. The tetrad is tetrahedral arranged and pollen grain is two celled at the time of shedding. The archesporial cell functions as macrospore mother cell directly. The tetrad is linear arranged. The ovule is anatropous, tenuinucellar, and unitegmic, and the embryo sac is of Polygonum type. Micropylar fertilization, the endosperm development follows the cellular type with a long and narrow binucleated and one celled chalazal haustorium and a two celled micropylar haustorium. The embryo development belongs to Onograd type. The results show that the embryological characteristics of \%Gesneriaceae\% is similar to that of \%Scrophulariaceae, Orobanchaceae\%, and \?anthaceae\%. The similarity presents that these families are close in systematics.