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Reproductive Biology and Relative Male and Female Fitness in a Trioecious Cactus, Pachycereus pringlei (Cactaceae)

1994; Wiley; Volume: 81; Issue: 7 Linguagem: Inglês

10.2307/2445767

1537-2197

Theodore H. Fleming, Sandrine Maurice, Stephen L. Buchmann, Merlin D. Tuttle,

Botany, Ecology, and Taxonomy Studies

American Journal of BotanyVolume 81, Issue 7 p. 858-867 Article Reproductive biology and relative male and female fitness in a trioecious cactus, Pachycereus pringlei (Cactaceae) Theodore H. Fleming, Theodore H. Fleming Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this authorSandrine Maurice, Sandrine Maurice Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this authorStephen L. Buchmann, Stephen L. Buchmann Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this authorMerlin D. Tuttle, Merlin D. Tuttle Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this author Theodore H. Fleming, Theodore H. Fleming Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this authorSandrine Maurice, Sandrine Maurice Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this authorStephen L. Buchmann, Stephen L. Buchmann Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this authorMerlin D. Tuttle, Merlin D. Tuttle Department of Biology, University of Miami, Coral Gables, Florida, 33124 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, 85721 USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tucson, Arizona, 85719 Bat Conservation International, P.O. Box 162603, Austin, Texas, 78716Search for more papers by this author First published: 01 July 1994 https://doi.org/10.1002/j.1537-2197.1994.tb15567.xCitations: 55 Author for correspondence (FAX: 305-284-3039). AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract We describe the breeding system of an autotetraploid trioecious cactus, Pachycereus pringlei, provide estimates of the fitnesses of males and females relative to that of hermaphrodites, and discuss the role played by pollinators in the maintenance of three sexual morphs. Relatively high frequencies of females (45%) and males (26%) exist in coastal desert populations around Bahia Kino, Sonora, Mexico. They differ from hermaphrodites in flower size (females only), initiation of the flowering season, number of flowers produced per night and per season, sucrose content of nectar, and, in females, number of fruits produced per season under open pollination and in response to hand-pollination. Major similarities between the sex classes include overall plant size, nectar volume per flower, percent fruit set in open-pollinated flowers of females and hermaphrodites, seed mass and number of seeds per fruit, and pollen mass per flower in males and hermaphrodites. Hermaphrodites are self-compatible, and the selfing rate is high (65%). Levels of inbreeding depression in selfed fruits and seeds appear to be low. Fruit set is strongly pollinator-dependent in females but much less so in hermaphrodites. Relative fitness of males and females, as measured by annual production of pollen or seeds, is at least 1.5 times higher than that of the corresponding sex function in hermaphrodites. Given the high selfing rate and apparent lack of inbreeding depression, these fitness differences are insufficient to explain the occurrence of trioecy in this species. Citing Literature Volume81, Issue7July 1994Pages 858-867 RelatedInformation