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345 results on '"Petit, Rémy J."'

8. Harmful self‐pollination drives gynodioecy in European chestnut, a self‐incompatible tree.

Author

Larue, Clément and Petit, Rémy J.

Subjects
*CHESTNUT, *SELF-pollination, *TREES, *FRUIT trees, *CASTRATION, *INFLORESCENCES
Abstract

Premise: Gynodioecy is a rare sexual system in which two genders (sensu Lloyd, 1980), cosexuals and females, coexist. To survive, female plants must compensate for their lack of siring capacity and male attractiveness. In European chestnut (Castanea sativa), an outcrossing tree, self‐pollination reduces fruit set in cosexual individuals because of late‐acting self‐incompatibility and early inbreeding depression. Could this negative sexual interaction explain the presence of females in this species? Methods: We studied gender variation in wild populations of European chestnut. In addition, we compared fruit set (the proportion of flowers giving fruits) and other key female fitness components as well as reproductive allocation between genders. We then performed emasculation experiments in cosexual trees, by removing nectar‐producing fertile male inflorescences. We also removed sterile but nectar‐producing male inflorescences from female trees, as a control. Results: We found a highly variable proportion of male‐sterile individuals in the wild in European chestnut. In the experimental plot, trees from each gender had similar size, flower density, and burr set, but different fruit set. Removing nectar‐producing male inflorescences from branches or entire trees increased fruit set in cosexual but not in female trees. Conclusions: These results show that self‐pollination impairs fruit set in cosexual trees. Female trees avoid these problems as they do not produce pollen but continue to attract pollinators thanks to their rewarding male‐sterile inflorescences, resulting in a much higher fruit set than in cosexuals. This demonstrates that even outcrossed plants can benefit from the cessation of self‐pollination, to the point that unisexuality can evolve. [ABSTRACT FROM AUTHOR]

Published
2024
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28. Glacial Refugia: Hotspots but Not Melting Pots of Genetic Diversity

Author

Petit, Rémy J., Aguinagalde, Itziar, de Beaulieu, Jacques-Louis, Bittkau, Christiane, Brewer, Simon, Cheddadi, Rachid, Ennos, Richard, Fineschi, Silvia, Grivet, Delphine, Lascoux, Martin, Mohanty, Aparajita, Müller-Starck, Gerhard, Demesure-Musch, Brigitte, Palmé, Anna, Martín, Juan Pedro, Rendell, Sarah, and Vendramin, Giovanni G.

Published
2003

35. Sexual interference revealed by joint study of male and female pollination success in chestnut.

Author

Larue, Clément, Klein, Etienne K., and Petit, Rémy J.

Subjects
CHESTNUT, POLLINATION, CASTANEA, PHANEROGAMS, FLOWER seeds, FRUIT seeds
Abstract

Most seed plants produce both pollen and ovules. In principle, pollen export could interfere with pollen import through self‐pollination, resulting in ovule usurpation and reduced fruit set. Evidence for such interference exists under experimental settings but its importance under natural conditions is unknown. To test for sexual interference in nature, it is necessary to study together mating system, through paternity analyses, and fruit set, the proportion of flowers giving seeds or fruits. We developed a new model combining both processes, using chestnut (Castanea) as case study. We carried out a paternity analysis in an intensively studied plot of 273 trees belonging to three interfertile chestnut species and including a range of individuals with more or less functional stamens, resulting in a large data set of 1924 mating events. We then measured fruit set on 216 of these trees. Fruit set of male‐fertile trees was much lower than that of male‐sterile trees. Our process‐based model shows that pollen is not limiting in the study site and hence cannot account for reduced fruit set. It also indicates that self‐pollination is high (74%) but selfing rate is low (4%). Self‐pollen is less competitive than cross‐pollen, reducing sexual interference, but not sufficiently, as many ovules end up being self‐fertilized, 95% of which abort before fruit formation, resulting in the loss of 46% of the fruit crop. These results suggest that the main cause of reduced reproductive potential in chestnut is sexual interference by self‐pollen, raising questions on its evolutionary origins. [ABSTRACT FROM AUTHOR]

Published
2023
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46. Authenticated DNA from Ancient Wood Remains

Author

LIEPELT, SASCHA, SPERISEN, CHRISTOPH, DEGUILLOUX, MARIE-FRANCE, PETIT, REMY J., KISSLING, ROY, SPENCER, MATTHEW, DE BEAULIEU, JACQUES-LOUIS, TABERLET, PIERRE, GIELLY, LUDOVIC, and ZIEGENHAGEN, BIRGIT

Published
2006

50. Definitions

Author

Kremer, Antoine, Petit, Rémy J., Pons, Odile, Karp, Angela, editor, Isaac, Peter G., editor, and Ingram, David S., editor

Published
1998
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