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Floral dimorphism, pollination, and self-fertilization in gynodioecious Geranium richardsonii (Geraniaceae) / C.F. Williams in American Journal of Botany, 87 (5) (05/2000) 

Public Citation [article]  inAmerican Journal of Botany > 87 (5) (05/2000) . - 661-669 Titre : Floral dimorphism, pollination, and self-fertilization in gynodioecious Geranium richardsonii (Geraniaceae) Type de document : Imprimé Auteurs : C.F. Williams ; Margaret A. Kuchenreuther ; A. Drew Année de publication : 2000 Article en page(s) : 661-669 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Biologie de la reproduction [CBNPMP-Thématique] Biologie florale, floraison Mots-clés : Geranium  Geranium richardsonii Résumé : The selective maintenance of gynodioecy depends on the relative fitness of the male-sterile (female) and hermaphroditic morphs. Females may compensate for their loss of male fitness by reallocating resources from male function (pollen production and pollinator attraction) to female function (seeds and fruits), thus increasing seed production. Females may also benefit from their inability to self-fertilize if selfing and inbreeding depression reduce seed quality in hermaphrodites. We investigated how differences in floral resource allocation (flower size) between female and hermaphroditic plants affect two measures of female reproductive success, pollinator visitation and pollen receipt, in gynodioecious populations of Geranium richardsonii in Colorado. Using emasculation treatments in natural populations, we further examined whether selfing by autogamy and geitonogamy comprises a significant proportion of pollen receipt by hermaphrodites. Flowers of female plants are significantly smaller than those of hermaphrodites. The reduction in allocation to pollinator-attracting structures (petals) is correlated with a significant reduction in pollinator visitation to female flowers in artificial arrays. The reduction in attractiveness is further manifested in significantly less pollen being deposited on the stigmas of female flowers in natural populations. Autogamy is rare in these protandrous flowers, and geitonogamy accounts for most of the difference in pollen receipt between hermaphrodites and females. Female success at receiving pollen was negatively frequency dependent on the relative frequency of females in populations. Thus, two of the prerequisites for the maintenance of females in gynodioecious populations, differences in resource allocation between floral morphs and high selfing rates in hermaphrodites, occur in G. richardsonii. Lien pérenne : DOI : 10.2307/2656852 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137575 Williams, C.F., Kuchenreuther, Margaret A., Drew, A. 2000 Floral dimorphism, pollination, and self-fertilization in gynodioecious Geranium richardsonii (Geraniaceae). American Journal of Botany, 87(5): 661-669.

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Consultable article (2000) URL

Molecular markers reveal little genetic differentiation among Aconitum noveboracense and A. colombianum (Ranunculaceae) populations / Christopher T. Cole (2001) 

Public Citation est un tiré à part de 88 (2) - 2001 (American Journal of Botany) Titre : Molecular markers reveal little genetic differentiation among Aconitum noveboracense and A. colombianum (Ranunculaceae) populations Type de document : Tiré à part de revue Auteurs : Christopher T. Cole ; Margaret A. Kuchenreuther Année de publication : 2001 Importance : 337-347 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Distribution de la diversité génétique [CBNPMP-Thématique] Variabilité, analyse de l'ADN, polymorphisme Mots-clés : Aconitum noveboracense  Aconitum columbianum  Aconitum reclinatum Résumé : Aconitum noveboracense, a rare, herbaceous perennial, is restricted to recently unglaciated areas in Iowa, Wisconsin, Ohio, and New York, and federally classified as a threatened species. These populations may be disjuncts of the common congener, A. columbianum Nutt., which occurs in the mountains of the western United States. Morphological characters do not reliably separate these taxa. The identity of Black Hills populations, located between the ranges of the rare and common species, is also uncertain. We characterized genetic variation within and among the Aconitum populations in question using isozymes and randomly amplified polymorphic DNA (RAPDs). Isozymes indicate a high degree of similarity among all populations and a high level of genetic diversity in Black Hills populations. Of 97 scorable RAPD loci, 89.7% are polymorphic and clearly resolve most populations. Like isozymes, RAPDs indicate high levels of genetic diversity in the Black Hills and very strong similarity of these populations to A. columbianum from the Bighorn Mountains. Aconitum noveboracense populations show >80% similarity to A. columbianum populations. A population of A. uncinatum from Ohio shows the greatest differentiation from other populations. Therefore, both isozyme and RAPD data concur with the recent treatment of A. noveboracense and A. columbianum as a single species. Lien pérenne : DOI : 10.2307/2657023 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=130767 Cole, Christopher T., Kuchenreuther, Margaret A. 2001 Molecular markers reveal little genetic differentiation among Aconitum noveboracense and A. colombianum (Ranunculaceae) populations. American Journal of Botany, 88(2) : 337-347.

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Consultable Article (2001) URL