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Title: Floral traits influence the opportunity for selection among male gametophytes: independent and combined effects of style length and petal area

Strong correlations between traits can obscure their independent effects on components of reproduction. Style length (SL) and petal area (PA) vary within species, for example, but their independent effects on the opportunity for selection among pollen genotypes are poorly understood. Previous work inClarkiadetected a positive effect ofSLon pollen receipt, potentially intensifying selection. However, this apparent effect ofSLmay be influenced by a correlated trait, such asPA. Here, we examine the independent effects of these two traits on pollen receipt and performance.


We collected petals and styles from wild populations of two insect‐pollinatedClarkiataxa and estimated the independent and combined effects ofSLandPAon pollen receipt and performance.


In both taxa,SLandPAare positively correlated. InC. unguiculata, both traits positively and independently affect pollen receipt, but inC. xantianassp.xantiana, the two traits act only in combination to affect pollen receipt. In both taxa, pollen receipt positively affects the numbers of pollen tubes entering and penetrating the style, as well as pollen tube attrition.


The effects ofSLandPAon pollen receipt and performance are taxon specific. InC. unguiculata, both traits may be independent targets of selection due to their effects on pollen receipt. InC. xantianassp.xantiana, by contrast, the combined (but not independent) effects ofSLandPAinfluence pollen receipt. Ecological differences between these taxa require exploration to understand the mechanisms by which these traits affect pollinator behavior.

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Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
American Journal of Botany
Page Range / eLocation ID:
p. 744-753
Medium: X
Sponsoring Org:
National Science Foundation
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