Auteur Allison A. Snow
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Documents disponibles écrits par cet auteur (3)
Affiner la rechercheDelayed autonomous self-pollination in Hibiscus laevis (Malvaceae) / Robert A. Klips in American Journal of Botany, 84 (1) (1997)
Titre : Delayed autonomous self-pollination in Hibiscus laevis (Malvaceae) Type de document : Imprimé Auteurs : Robert A. Klips ; Allison A. Snow Année de publication : 1997 Article en page(s) : 48-53 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Biologie de la reproduction Mots-clés : Hibiscus Hibiscus moscheutos Résumé : Delayed autonomous self-pollination allows outcrossing to occur while also ensuring that seeds are produced in the absence of pollen vectors. We investigated variation in the efficacy of this pollination mechanism in populations of Hibiscus laevis. Recurvature of stylar branches occurred after 1 d of anthesis, and in plants from Ohio, Illinois, Arkansas, and Oklahoma this behavior resulted in autonomous selfing (surprisingly, stylar movement was facultative in that it did not take place when the stigmas were already pollinated). In contrast to these more northern populations, the distance between anthers and stigmas was too great to allow autonomous selfing in plants from Texas, Mississippi, and Louisiana. Greenhouse studies of plants from Ohio demonstrated that autonomous selfing resulted in an average of 29.5 seeds per flower, as compared to 59.9 seeds per flower from hand-pollination of stigmas with self pollen. In an assessment of the possible significance of this selfing mode, emasculated flowers did not set significantly fewer seeds in a natural stand in Ohio, suggesting that few seeds resulted from autonomous selfing at that site. Modest inbreeding depression was detected at this population. Our results suggest that delayed autonomous selfing is more common in northern populations, where it may facilitate population establishment and persistence at times when pollinators are scarce. Identifiant : DOI : 10.2307/2445882 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137613
in American Journal of Botany > 84 (1) (1997) . - 48-53Klips, R.A., Snow, A.A., 1997 . Delayed autonomous self-pollination in Hibiscus laevis (Malvaceae). American Journal of Botany, 84(1): 48-53.Documents numériques
Article (1997)URL
Titre : Growth and fecundity of fertile Miscanthus × giganteus (“PowerCane”) compared to feral and ornamental Miscanthus sinensis in a common garden experiment: Implications for invasion Type de document : Imprimé Auteurs : Maria N. Miriti ; Tahir Ibrahim ; Destiny Palik ; Catherine Bonin ; Emily Heaton ; Evans Mutegi ; Allison A. Snow Année de publication : 2017 Article en page(s) : 5703-5712 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Mots-clés : Bromus inermis Leyss. Panicum virgatum Résumé : Perennial grasses are promising candidates for bioenergy crops, but species that can escape cultivation and establish self-sustaining naturalized populations (feral) may have the potential to become invasive. Fertile Miscanthus × giganteus, known as “PowerCane,” is a new potential biofuel crop. Its parent species are ornamental, non-native Miscanthus species that establish feral populations and are sometimes invasive in the USA. As a first step toward assessing the potential for “PowerCane” to become invasive, we documented its growth and fecundity relative to one of its parent species (Miscanthus sinensis) in competition with native and invasive grasses in common garden experiments located in Columbus, Ohio and Ames, Iowa, within the targeted range of biofuel cultivation. We conducted a 2-year experiment to compare growth and reproduction among three Miscanthus biotypes—”PowerCane,” ornamental M. sinensis, and feral M. sinensis—at two locations. Single Miscanthus plants were subjected to competition with a native grass (Panicum virgatum), a weedy grass (Bromus inermis), or no competition. Response variables were aboveground biomass, number of shoots, basal area, and seed set. In Iowa, all Miscanthus plants died after the first winter, which was unusually cold, so no further results are reported from the Iowa site. In Ohio, we found significant differences among biotypes in growth and fecundity, as well as significant effects of competition. Interactions between these treatments were not significant. “PowerCane” performed as well or better than ornamental or feral M. sinensis in vegetative traits, but had much lower seed production, perhaps due to pollen limitation. In general, ornamental M. sinensis performed somewhat better than feral M. sinensis. Our findings suggest that feral populations of “PowerCane” could become established adjacent to biofuel production areas. Fertile Miscanthus × giganteus should be studied further to assess its potential to spread via seed production in large, sexually compatible populations. Identifiant : DOI : 10.1002/ece3.3134 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=149375
in Ecology and evolution > 7 (15) (2017) . - 5703-5712Miriti, M.N., Ibrahim, T., Palik, D., Bonin, C., Heaton, E., Mutegi, E., Snow, A.A., 2017 . Growth and fecundity of fertile Miscanthus × giganteus (“PowerCane”) compared to feral and ornamental Miscanthus sinensis in a common garden experiment: Implications for invasion. Ecology and evolution, 7(15): 5703-5712.Documents numériques
Article (2017)URL
Titre : Pollen-tube competition and male fitness in Hibiscus moscheutos Type de document : Imprimé Auteurs : Allison A. Snow ; Timothy P. Spira Année de publication : 1996 Article en page(s) : 1866-1870 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Biologie de la reproduction Mots-clés : Hibiscus moscheutos Hibiscus Résumé : The stigmas of animal-pollinated flowers often capture more pollen than is needed to fertilize all available ovules, and mixed-donor pollen loads are probably common. When this is the case, variation in average pollen-tube growth rates can potentially affect the number of seeds sired by a given plant. Despite considerable interest in effects of postpollination processes on male fitness, little is known about the extent of variation in pollen performance among plants from natural populations. To examine this question in Hibiscus moscheutos (rose mallow), we conducted mixed-donor hand-pollination experiments with 39 pollen donors bearing distinctive isozyme markers. Pairs of competing donors were compared on sets of 11 to 15 recipient plants per pair. These donors often differed in the proportions of seeds they sired, with the maximum deviation from an expected ratio of 50:50 being 68:32. Furthermore, three intensively studied plants exhibited consistent trends in relative pollen performance when each was tested against (1) the same three competitors, and (2) groups of 14 competitors chosen at random from the study population. In a separate experiment, we investigated the effects of salinity stress and high soil nutrients on pollen performance. These environmental factors had anticipated effects on leaf production, flower production, and petal length, but style length and (most importantly) the number of seeds sired relative to a standard pollen donor were not affected. In summary, this study provides the strongest evidence to date that pollen-tube competitive ability varies among coexisting plants and may be an important component of male fitness in plants. Identifiant : DOI : 10.2307/2410744 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137614
in Evolution > 50 (5) (1996) . - 1866-1870Snow, A.A., Spira, T.P., 1996 . Pollen-tube competition and male fitness in Hibiscus moscheutos. Evolution, 50(5): 1866-1870.Documents numériques
article (1996)URL
