Early Stages of Anther Development in Flowering Plants

Abstract

The analysis showed that when studying the anther of flowering plants there is a complex of unsolved embryological problems. First of all, they relate to the first stages of microsporangium initiation and time of archesporium differentiation. Many of classifications of microsporangium wall formation were worked out on the base of parietal tissue formation features. Of the 4 types of microsporangium wall formation proposed by Davis (1966), 2 types (basic and reduced) are controversial. In the classification by Teryokhin et al. (1993, 2002), the basic type was included as a complicated variation in the centripetal type, and the reduced type as a reduced variation in the centrifugal type. In our opinion, in angiosperms only two types of formation of microsporangium wall layers can be distinguished: centrifugal and centripetal. As our study has shown, the reduced type, as well as, the basic one, are variations of the centripetal type, while the reduced type is a modification of the typical variation. Various points of view on the formation of microsporangium layers are discussed not only from the outside of the parietal cells, but also from the lateral and internal sides.