|Title||Pollen vigour and the potential for sexual selection in plants|
|Publication Type||Journal Article|
|Year of Publication||1991|
|Authors||Snow AA, Spira TP|
Discovering whether paternal fecundity varies within populations is crucial for evaluating whether male-male competition and/or female choice can lead to sexual selection. In natural populations of plants, pollinators often deposit mixtures of 'surplus' pollen from several individuals onto receptive stigmas. Therefore within-flower competition among pollen-tubes for ovules could lead to nonrandom paternal success. We found that pollen competition was common in populations of wild rose mallow (Hibiscus moscheutos). Co-occurring individuals often differed in mean pollen-tube growth rates, and this trait was correlated with the number of seeds the plants sired when pollen mixtures were applied to stigmas. Differences between pairs of individuals in pollen-tube growth rates were consistent across maternal plants, suggesting that sexual selection can occur. This unexpected variation in pollen vigour could lead to nonrandom fertilization whenever pollen-tubes compete for access to ovules.