J Syst Evol ›› 1995, Vol. 33 ›› Issue (5): 444-452.

• Research Articles • Previous Articles     Next Articles

Embryological Studies in Polygonatum humile Fisch. ex Maxim

Rao Guang‐yuan, Pan Kai‐yu   

  • Published:1995-09-10

Abstract: Embryology of Polygonatum humile Fisch.ex Maxim.was studied in the present work. The anther was found to be 4-sporangiate. The tapetum,of which each cell contained two or many nuclei at the late stage, was the Glandular type. Metosis of the microspore mother cells was accompanied by successive cytokinesis,and resulted in isobilateral and tetrahedral tetrads. The mature pollen grains were of 2-celled type. The ovary was trilocular. The placentation was axile,but the sutures of carpels were not fully fused in the center of the ovary above the placentas. The ovule was biteguminous, crassinucellate and anatropous.The micropyle was formed by the inner integument.The development of the embryo sac was of the Allium type.Raphides were observed in the ovary wall and the outerintegument after fertilization.The development of the embryo was similar to the Asterad type.The endosperm was of the Nuclear type. The gigantic endosperm nucleus was formed and not cellulated at the chalazal end. According to the data from the present and previous works,the embryological characters of Polygonatum were described.The concept and circumscription of the tribe Polygonateae proposed by Dahlgren et al.(1985) were discussed with the comparison of the embryological data in and out of the tribe.Meanwhile,the systematic relationships between the genera of the tribe were also discussed.

Key words: Polygonatum, Polygonatum humile, Embryology, Polygonateae, Systematic relationship