TARBAEVA, VERONICA. Department of Botany, Syktyvkar State University, Syktyvkar, Russia 167001. - Structural evolution of seeds in gymnosperms.
Evaluation and information of seed structure for systematics and
phylogenetic considerations of angiosperm plants are reflected in a
number of compiling monographs (Netolitzky, 1926; Corner, 1976;
“Comparative anatomy of seeds”, 1985-1999). However, publications
devoted comparative seed anatomy of gymnosperms are a few
(Chamberlain, 1935; Schnarf, 1937). Morphology and anatomy of
developing and mature seeds and ultrastructure of seed coats of
gymnosperms (124 species from 51 genera from 16 families) were studied
during 1984-1998. During these long-term investigations it is
established: 1) main evolutionary structural types of gymnosperm
seeds; 2) peculiarities of histogenesis of seed coats in relation to
their origin in different gymnosperm taxa; 3) classification of
systematic evaluating characters of seed structure on species, genus,
family, class levels, using complex analysis; 4) revision different
systems of gymnosperms and 5) new phylogenetic scheme of gymnosperms.
Obtained data are published in two monographs in Russia (Tarbaeva,
1995; 1997), but the phylogenetic scheme isn’t yet published.
Key words: evolution, gymnosperms, seed structure, systematics, ultrastructure