Selective advantage of ray florets in Scalesia affinis and S. pedunculata (Asteraceae), two endemic species from the Galápagos

Lene Rostgaard Nielsen; Marianne Philipp; Hans R. Siegismund

doi:10.1023/A:1016301027929

Selective advantage of ray florets in Scalesia affinis and S. pedunculata (Asteraceae), two endemic species from the Galápagos

Lene Rostgaard Nielsen, Marianne Philipp, Hans R. Siegismund

25 Citations (Scopus)

Abstract

The presence of neuter ray florets in species within Asteraceae is generally believed to increase pollinator attraction. In the endemic Galápagos genus Scalesia (Asteraceae) a natural variation in the presence/absence of neuter ray florets is found. To evaluate whether the presence of ray florets plays a selective role on female reproductive success we chose two species of Scalesia, Scalesia affinis that carries ray florets and S. pedunculata that is rayless. On Santa Cruz Island capitula of S. pedunculata were equipped with fake ray florets while others were untouched. On Isabela Island ray florets were removed on half of the capitula of S. affinis. In S. affinis rayed capitula received more pollinators and more pollen, which resulted in a significantly higher embryo production. In S. pedunculata no effect on embryo production was found. The disagreement between the two species may correspond to a difference in visitation frequency, S. pedunculata receiving many more visit than S. affinis. Thus, ray floret development proved beneficial in pollinator-restricted localities.

Original language	English
Journal	Evolutionary Ecology
Volume	16
Issue number	2
Pages (from-to)	139-153
Number of pages	15
ISSN	1573-8477
DOIs	https://doi.org/10.1023/A:1016301027929
Publication status	Published - 2002

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@article{61b5a6f2a6c94fb797af7fb2840c79b5,

title = "Selective advantage of ray florets in Scalesia affinis and S. pedunculata (Asteraceae), two endemic species from the Gal{\'a}pagos",

abstract = "The presence of neuter ray florets in species within Asteraceae is generally believed to increase pollinator attraction. In the endemic Gal{\'a}pagos genus Scalesia (Asteraceae) a natural variation in the presence/absence of neuter ray florets is found. To evaluate whether the presence of ray florets plays a selective role on female reproductive success we chose two species of Scalesia, Scalesia affinis that carries ray florets and S. pedunculata that is rayless. On Santa Cruz Island capitula of S. pedunculata were equipped with fake ray florets while others were untouched. On Isabela Island ray florets were removed on half of the capitula of S. affinis. In S. affinis rayed capitula received more pollinators and more pollen, which resulted in a significantly higher embryo production. In S. pedunculata no effect on embryo production was found. The disagreement between the two species may correspond to a difference in visitation frequency, S. pedunculata receiving many more visit than S. affinis. Thus, ray floret development proved beneficial in pollinator-restricted localities.",

author = "Nielsen, {Lene Rostgaard} and Marianne Philipp and Siegismund, {Hans R.}",

year = "2002",

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language = "English",

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pages = "139--153",

journal = "Evolutionary Ecology",

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publisher = "Springer",

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TY - JOUR

T1 - Selective advantage of ray florets in Scalesia affinis and S. pedunculata (Asteraceae), two endemic species from the Galápagos

AU - Nielsen, Lene Rostgaard

AU - Philipp, Marianne

AU - Siegismund, Hans R.

PY - 2002

Y1 - 2002

N2 - The presence of neuter ray florets in species within Asteraceae is generally believed to increase pollinator attraction. In the endemic Galápagos genus Scalesia (Asteraceae) a natural variation in the presence/absence of neuter ray florets is found. To evaluate whether the presence of ray florets plays a selective role on female reproductive success we chose two species of Scalesia, Scalesia affinis that carries ray florets and S. pedunculata that is rayless. On Santa Cruz Island capitula of S. pedunculata were equipped with fake ray florets while others were untouched. On Isabela Island ray florets were removed on half of the capitula of S. affinis. In S. affinis rayed capitula received more pollinators and more pollen, which resulted in a significantly higher embryo production. In S. pedunculata no effect on embryo production was found. The disagreement between the two species may correspond to a difference in visitation frequency, S. pedunculata receiving many more visit than S. affinis. Thus, ray floret development proved beneficial in pollinator-restricted localities.

AB - The presence of neuter ray florets in species within Asteraceae is generally believed to increase pollinator attraction. In the endemic Galápagos genus Scalesia (Asteraceae) a natural variation in the presence/absence of neuter ray florets is found. To evaluate whether the presence of ray florets plays a selective role on female reproductive success we chose two species of Scalesia, Scalesia affinis that carries ray florets and S. pedunculata that is rayless. On Santa Cruz Island capitula of S. pedunculata were equipped with fake ray florets while others were untouched. On Isabela Island ray florets were removed on half of the capitula of S. affinis. In S. affinis rayed capitula received more pollinators and more pollen, which resulted in a significantly higher embryo production. In S. pedunculata no effect on embryo production was found. The disagreement between the two species may correspond to a difference in visitation frequency, S. pedunculata receiving many more visit than S. affinis. Thus, ray floret development proved beneficial in pollinator-restricted localities.

U2 - 10.1023/A:1016301027929

DO - 10.1023/A:1016301027929

M3 - Journal article

SN - 0269-7653

VL - 16

SP - 139

EP - 153

JO - Evolutionary Ecology

JF - Evolutionary Ecology

IS - 2

ER -