[article]
Titre : |
Does self-pollination provide reproductive assurance in Aquilegia canadensis (Ranunculaceae)? |
Type de document : |
Imprimé |
Auteurs : |
Christopher George Eckert (1960-) ; A. Schaefer |
Année de publication : |
1998 |
Article en page(s) : |
919-924 |
Langues : |
Anglais (eng) |
Mots-clés : |
Aquilegia sp. Aquilegia canadensis |
Résumé : |
The ability to produce seeds when pollinators or potential mates are scarce is thought to be one of the main advantagesof self-fertilization in flowering plants. However, whether autonomous selfing increases seed set in natural populations hasseldom been tested, and even fewer studies have evaluated the advantage of selfing across a gradient of pollen availability.This study examines the fertility consequences of autonomous selfing inAquilegia canadensis(Ranunculaceae), a short-lived, spring-flowering perennial typically found in small, patchy populations on rock outcrops. We used a pollinator exclu-sion experiment to confirm reports thatA. canadensishas a well-developed capacity for autonomous selfing resulting fromincomplete protogyny and close proximity of stigmas and anthers during dehiscence. Flowers excluded from pollinators set87% as many seeds per carpel (X ̄61SE57.161.4 seeds) as hand-pollinated flowers (8.161.3 seeds), and seedproduction in unpollinated flowers correlated negatively with the distance between stigmas and anthers (r520.46). Au-tonomous selfing could be potentially valuable in providing reproductive assurance because only 2.760.5 pollen grainswere deposited on each stigma before anther dehiscence, compared to 134.1617.9 pollen grains by the end of antherdehiscence. However, prevention of autonomous selfing by anther removal before dehiscence did not decrease seed set, evenfor plants at low plant densities where outcross pollen may have been in short supply. Emasculated flowers set as manyseeds per carpel (9.360.9) as intact flowers (8.461.1), indicating that sufficient cross pollen is deposited for full seedset. These results do not support the hypothesis that autonomous selfing byA. canadensishas been selected because itprovides reproductive assurance. |
Lien pérenne : |
DOI : 10.2307/2446357  |
Permalink : |
https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137833 |
in American Journal of Botany > 85 (7) (07/1998) . - 919-924
Eckert, Christopher George (1960-), Schaefer, A.
1998
Does self-pollination provide reproductive assurance in Aquilegia canadensis (Ranunculaceae)?
American Journal of Botany, 85(7): 919-924.
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