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Distribution And Evolution Of Forms And Types Of Sieve-Element Plastids In The Dicotyledons, Dietmar Behnke
Distribution And Evolution Of Forms And Types Of Sieve-Element Plastids In The Dicotyledons, Dietmar Behnke
Aliso: A Journal of Systematic and Floristic Botany
Sieve-element plastids may contain any combination of protein crystals (c), protein filaments (f), and starch grains (s), or none of these. All structurally distinct combinations (=forms) possible (s, cs, cfs, c, cf, fs, f, o) are recorded among the 2100 dicotyledons investigated so far with the transmission electron microscope (representing 381 of more than 460 families described). The six forms that include c and/or f define the P-type and are found in some 620 species, mainly confined to Magnolianae, Caryophyllanae, Vitanae, and Rutanae (Fabales, Linales, Rhizophorales). A detailed family-by-family analysis and quantitative form-by-form comparison suggests that form-Ss plastids give rise …
Steps Toward A Natural System Of The Dicotyledons, Uwe Jensen
Steps Toward A Natural System Of The Dicotyledons, Uwe Jensen
Aliso: A Journal of Systematic and Floristic Botany
Nucleic acids and proteins provide useful characters for the elucidation of evolutionary relationships. Those protein molecules, e.g., legumins, which are subject to less influence of selection processes, have proven to be most valuable as diagnostic characters in phylogenetic studies. Three systematic investigations conducted using comparative serological legumin analyses are discussed as contributions aiding botanists' understanding of a natural system of classification.
Steps Toward A Natural System Of The Dicotyledons, Gertrud Dahlgren
Steps Toward A Natural System Of The Dicotyledons, Gertrud Dahlgren
Aliso: A Journal of Systematic and Floristic Botany
Embryological character states are mapped on the diagrams of dicotyledons (G. Dahlgren 1989). The often well-defined pattern of distribution forms a basis for discussing and clarifying phylogenetic relations. It is shown how numerous embryological characters, alone or in combinations, support certain systematic constellations, even if the character states may have arisen independently within a varying number of evolutionary lines. Characters presented are: anther wall formation; tapetum types; cells in pollen grains at dispersal; microsporogenesis; ovule morphology; ovule integuments; endothelium; obturator; parietal tissue; embryo sac formation; antipodal cells; hypostase, embryogeny; polyembryony; endosperm formation; persistence of endosperm; ruminate endosperm; endosperm haustoria; perisperm; …