Different ways to obtain similar results. The development of the corolla and epipetaly in herbaceous Rubioideae (Rubiaceae) (presenting author)

Onderzoeksoutput: Bijdrage aan congresGepubliceerd abstract

Rubiaceous flowers are described as having a calyx with basally fused lobes and a tubular corolla with epipetalous stamens. In several tropical Rubiaceae, floral developmental investigations revealed that the corolla is early sympetalous and that a stamen corolla tube develops from an annular primordium. Other species showed late sympetaly with a rudimentary or absent stamen corolla tube and no epipetaly. Payer observed individual petal primordia postgenitally fusing with the filaments in herbaceous European Rubieae. A floral cup results with only the distal parts of the filaments free. In this study, we want to test the hypothesis that rubioid tubular corollas result from three developmental processes; 1) the
development of a stamen-corolla tube from a common annular primordium, 2) the development of a corolla tube sensu stricto from an annular intercalary meristem, and 3) postgenital fusion of petals or corolla lobes. Following Goethes “Prinzip der variablen Proportionen”, we hypothesize that these processes are differently expressed depending on the species. We investigate the development of the perianth and androecium in herbaceous species within Rubioideae.
In temperate Phuopsis and tropical Richardia, a stamen-corolla tube with epipetalous stamens is formed. In contrast, in Asperula, Galium, and Rubia, the floral cup results from postgenital fusion of initially free petals and filaments, as also reported by Payer. In Phuopsis, the stamens are inserted half-way in the corolla tube because of the development of a corolla tube sensu stricto, which is absent or rudimentary in Richardia. The development in these two species concurs with our hypothesis, but in Asperula, Galium and Rubia a stamen-corolla tube and corolla tube sensu stricto are absent and the floral cup results from postgenital fusion between filaments and petals. Consequently, the tube is a compound structure, composed from two different whorls with pseudo-epipetaly.
Originele taal-2Engels
Aantal pagina's1
StatusGepubliceerd - sep.-2017
EventVII International Rubiaceae and Gentianales Conference - Copenhagen, Denmark, Denemarken
Duur: 11-sep.-201713-sep.-2017


CongresVII International Rubiaceae and Gentianales Conference
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