Апоміксис у Potentilla argentea L. (Rosaceae)

Abstract

The reproductive process has been studied in Potentilla argentea L. ОvuІе is anatropic, crassinucellate with one integument. The numer of archesporial cells varies; Sporogenous complex is two-layered. Two or three sporogenous cells transform іntо megasporocytes. Two tetrads of megaspores develop according to standard. Embryo sacs of sexual individuals develop from the chalasal megaspore as а rule .. The rest megaspores are viable also, most of ten they are submicropylar. Megasporocytes or tetrads of megasapores of the apomictis individuals degenerate. Apomictic embryo sacs develop from somatic cells of chalasal nucellus zone. Double­or tetra-nuclear stage is achieved bу some aposporic embryo sacs, but one or two ones pass the complete differentiation. The specific from of apomixis is apospory, which is the indнced parthenogenesis (pseudogamy). The fertillization of (tiploid ovule was discovered. The correlation of reproductive · process and apomixis in different populations is variable.