Embryology of Adenosma Bilabiatum (Roxb.) Merr. (=A. capitatum Benth.) (Scrophulariaceae)

Adenosma bilabiatum (Roxb.) Merr.（玄參科）的胚胎學

H. G. V. G. Urs ； Jayaraj M.

《TAIWANIA》 44卷3期 (1999/09) Pp. 355-367

https://doi.org/10.6165/tai.1999.44(3).355

摘要

花藥為四孢子型。花藥壁之發育為雙子葉型。分泌型營養層為單層細胞且為雙重起源。四分小孢子為四分錐形體。花藥開裂時花粉粒為二細胞期且具三個萌芽孔。胚珠為單層珠被，薄珠心，倒生胚珠型。雌配子體的發育為蓼型。受精作用是經由珠孔。胚乳是細胞型具單細胞合點端吸器，而珠孔端吸器起源時為四細胞，但由於吸器細胞之細胞壁的瓦解而成為具四核之單細胞。胚胎發育為柳葉菜型。種皮薄具一明顯表皮層。

關鍵字

胚胎學 ； Adenosma bilabiatum (Roxb.) Merr. ； 玄參科

並列摘要

Anthers are tetrasporangiate. Anther wall development is of the dicotyledonous type. The glandular tapetum is single-layered and exhibits dual origin. Microspore tetrads are tetrahedral. Pollen grains at the time of anther dehiscence are two-celled and triaperturate. Ovules are unitegmic, tenuinucellar and anatropous. Development of female gametophyte conforms to the Polygonum type. Fertilization is porogamous. Endosperm is celluar with a single-celled chalazal haustorium, while the micropylar haustorium is initially four-celled, but becomes single-celled and quadrinucleate by the breakdown of the walls of the haustorial cells. Embryo development conforms to Onagrad type. Seed coat is thin with a prominent epidermal layer.

並列關鍵字

Embryology ； Adenosma bilabiatum ； Scrophulariaceae