Über Beziehungen zwischen Pollenmorphologie und Polyploidiestufen im Verwandtschaftsbereich der Gattung Phyllanthus. (Euphorbiaceae) Mit 1 Abbildung und 3 Tafeln

Abstract

Die Chromosomenzahlen von 18 Arten der Gattungen Phyllanthus, Breynia, Fluggea und Margaritaria werden zum Pollentyp der Sippen in Beziehung gesetzt und dabei Korrelationen zwischen den Aperturverhältnissen der Pollenkörner und den verschiedenen Polyploidiestufen festgestellt. Während in der diploiden Ebene nur 3‐colporater Pollen auftritt, lassen sich mit dem Übergang zur tetraploiden Stufe Tendenzen zur Vermehrung der Aperturen, zur teilweisen Verdoppelung der Ora, zur Syncolpie und zur Pantoposition der Aperturen beobachten, die sich in höheren Ploidiestufen nicht wesentlich erweitern. Diese Befunde werden in Verbindung mit Beobachtungen anderer Autoren an künstlichen und natürlichen Polyploiden diskutiert und auf die mögliche Bedeutung der Polyploidisierungen für die Evolution der Pollenformen hingewiesen.

Pollen morphology and systematics of palaeotropicalPhyllanthusand related genera of subtribe Phyllanthinae (Euphorbiaceae)

“…The conclusions of Köhler (1967) and Punt (1967) that the genera of subtribe Flueggeinae (s.s.) -Flueggea, Margaritaria, and Richeriella -display the plesiomorphic condition of prolate grains, elongated bordered monoporate colpi, and perforate-tectate to reticulate exine are consistent with Sagun & Van der Ham (2003). However, there is some difference in the pores of Margaritaria, which are circular to broadly elliptical with rounded ends, and the distinctly lalongate pores with pointed ends found in Flueggea and Richeriella.…”

“…A number of models of the evolution of pollen grains in the Phyllanthoideae have been published, including those of Köhler (1967) and Punt (1967). Köhler emphasized the correlation between advancing levels of polyploidy and increases in the number of colpi and pores, culminating in the clypeate (‘synrugoidorate’) pollen grains of high‐polyploid species of Phyllanthus subgenus Xylophylla .…”

“…Both models are useful in phylogenetic analyses of the subtribe Phyllanthinae. Köhler (1967) suggested that the plesiomorphic state in pollen morphology would include a prolate shape, tectate‐porate exine, elongated monoporate colpi, and lalongate elliptical pores. This is consistent with the model of Punt (1967, 1986), which postulates a number of morphological changes in shape (prolate to oblate), colpal length (elongated to porate), endoaperture (elliptic to circular), number of pores (monoporate to diploporate), and exine sculpturing (reticulate to vermiculate or inordinate).…”

SEM investigation of pollen from the lower Eocene (Carinthia and Salzburg in Austria and Brixton, London area, in England): new findings of Vitaceae, Euphorbiaceae, Phyllanthaceae, Fabaceae, Anacardiaceae, Araliaceae and Apiaceae

“…and Margaritaria L. depicted in Köhler (1967 Köhler (1965;pollen) and Webster (1984; floral morphology).…”

Identification, Validation and Classification of the Genus Phyllanthus in Nigeria Using ITS Genetic Marker and the Taxonomic Implication

“…The diversity of pollen types (Ko¨ hler, 1965(Ko¨ hler, , 1967Punt, 1967Punt, , 1987Webster and Carpenter, 2002;Sagun and Van der Ham, 2003) rivals that of any genus of flowering plants. The vast majority of Phyllanthus species, however, share a distinctive vegetative specialization known as ''phyllanthoid branching'' (Webster, 1956) with leaves on the main axes reduced to scales called ''cataphylls'' and those on lateral (plagiotropic), deciduous, floriferous axes developing normally.…”