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Seed germination of american pokeweed (Phytolacca americana). I. Laboratory techniques and autotoxicity / Maurice E. Edwards in American Journal of Botany, 75 (12) (1988)

Public Citation [article]  inAmerican Journal of Botany > 75 (12) (1988) . - 1794-1802 Titre : Seed germination of american pokeweed (Phytolacca americana). I. Laboratory techniques and autotoxicity Type de document : Imprimé Auteurs : Maurice E. Edwards ; Elizabeth M. Harris ; Frederic H. Wagner ; M. Catherine Cross ; Gregory S. Miller Année de publication : 1988 Article en page(s) : 1794-1802 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Plantes subspontanées, naturalisées, envahissantes Mots-clés : Phytolacca americana L., 1753 Résumé : Seeds of pokeweed (Phytolacca americana L.), an underinvestigated species, were studied to determine optimal conditions for laboratory germination. Soaking seeds in acid solutions prior to sowing increased rates of germination. Concentrated (conc) H2SO4 was more effective than conc NO3 or conc HCl acids. Physiological evidence from seed germination studies suggests that autotoxicity, or intraspecific inhibition, exists in pokeweed, a species known to possess several biologically active compounds. Seed germination was investigated in the laboratory with aqueous extracts of vegetative and reproductive structures of the plant. The presence of extracts from most plant parts correlated with reduced or no germination by seeds of its own species, whereas the presence of distilled water correlated with high percentages of germination by control seeds. Whether diluted with water by 5-fold (20% v/v) or undiluted, juice of pokeweed fruits completely inhibited the laboratory germination of pokeweed seeds. Also, extracts of freshly harvested mature leaves, stems, and immature fruits inhibited seed germination. However, results with root extracts, obtained from a single individual, depended more on concentration, since the highest concentration (50% v/v) inhibited germination, and lower concentrations (10 and 20% v/v) increased germination percentages over control samples. Results with extracts of juvenile leaves correlated with neither inhibition nor promotion of germination. Thus, except for juvenile leaves and the root, most extracts of the pokeweed plant inhibited seed germination with more mature structures exerting more inhibition and less mature structures exerting less or no inhibition. The ecological implication of autotoxicity is that seeds are more dispersed through time and space. In regard to seed germination by other species, especially those taxa known to possess biologically active compounds, these and other results suggest that the phenomenon of autotoxicity might be more widespread than previously suspected. Lien pérenne : DOI : 10.1002/j.1537-2197.1988.tb11260.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=151252 Edwards, Maurice E., Harris, Elizabeth M., Wagner, Frederic H., Cross, M. Catherine, Miller, Gregory S. 1988 Seed germination of american pokeweed (Phytolacca americana). I. Laboratory techniques and autotoxicity. American Journal of Botany, 75(12): 1794-1802.