Embryological Studies in the Family Saxifragaceae (S.L.). I. Development of the Ovule and Embryo Sac in Saxifraga Fortunei Var. Partita (Makino) Nakai

Abstract

The development of the ovule, megaspore and megagametophyte in Saxifraga fortunei var. partita (Makino) Nakai was observed. The ovule is anatropous, bitegmic, and crassinucellate. Both integuments originate from the epidermis. The archesporium is considered to be multicellular. The primary sporogenous cell functions as the megaspore mother cell which forms a T‐shaped tetrad. The chalazal member of the megaspore tetrad is functional and develops into a Polygonum‐type embryo sac. In the pyriform synergids the filiform apparatus is observed, but any hook or indentations could not be recognized. The antipodal cells are detectable until the Helobial endosperm undergoes several nuclear divisions. Secondary multiplication of the nuclei or the cells of the antipodals could not be observed.