Keywords
embryo sacs
floral development
gynoecium
hypostase
mamelon
Nuytsia
Atkinsonia
sacos embrionarios
desarrollo floral
gineceo
hipostasa
mamelón
Nuytsia
How to Cite
Abstract
Introducction: Gaiadendron punctatum is a hemiparasitic species of Loranthaceae (Tribe Gaiadendreae) that is widely distributed in mountainous regions of Central and South America. Embryological and phylogenetic studies in the family indicate a trend towards reduction of the gynoecium and ovules, the morphology of which supports the current circumscription of Tribe Gaiadendreae (Gaiadendron and Atkinsonia). Molecular phylogenetic studies suggest that Nuytsia, Atkinsonia and Gaiadendron diverged successively, forming a grade at the base of the Loranthaceae, but support values are low. Objetive: In the present study, the floral anatomy of Gaiadendron punctatum was investigated in order to provide additional data to permit comparisons among the three basal-most genera in the Loranthaceae and reevaluate their relationships. Methods: Flowers of G. punctatum were collected at different developmental stages and serial sections were prepared and analyzed by light microscopy. Results: Inflorescence development is acropetal; the flowers are bisexual with an inferior ovary surmounted by a calyculus, a ring-shaped structure lacking vascular tissue; the ovary is comprised of seven basal locules, each with an ategmic, tenuinucellate ovule. Above the locules is a mamelon that is fused with the adjacent tissues. The androecium is comprised of seven epipetalous stamens, the anthers with fibrous endothecium dehiscence through a single longitudinal slit, releasing tricolpated pollen. Conclusions: The results of this study show that Gaiadendron and Atkinsonia share versatile, dorsifixed anthers, while Gaiadendron and Nuytsia share the same mode of anther dehiscence. On the other hand, Gaiadendron shares with members of Tribe Elytrantheae an amyliferous mamelon and an unvascularized calyculus. Combined phylogenetic analyses of morphological and molecular data are desirable to determine whether Tribe Gaiadendreae comprises a clade, a grade or if the two genera are more distantly related.
References
Bhatnagar, S., & Johri, B.M. (1983). Embryology of Loranthaceae. In M. Calder & B. Peter (Eds.), The biology of mistletoes (pp. 129–143). University of Melbourne, Australia.
Cid-Villamil, R.M. (2006). Biología del desarrollo de Cladocolea loniceroides (Van Tieghem) Kuijt (Loranthaceae). Tesis de Doctorado, Universidad Nacional Autónoma de México, México.
Cocucci, A.E. (1982). El ovulo y el gineceo en Loranthaceae. Boletín de la Sociedad Argentina de Botánica, 21, 131–141.
Dixit, S. (1958). Morphological and Embryological Studies in the Family Loranthaceae IV. Amyema Van Tiegh. Phytomorphology, 8, 346–364.
Dueñas-Gómez, H.C. (2015). Loranthaceae. En R. Bernal, S. Gradstein, & M. Celis (Eds.), Catálogo de plantas y líquenes de Colombia (pp. 1487–1493). Editorial Universidad Nacional de Colombia.
Dueñas-Gómez, H.C., & Franco-Roselli, P. (2001). Sinopsis de las Loranthaceae de Colombia. Caldasia, 23, 81–99.
Garg, S. (1958). Embryology of Atkinsonia ligustrina (A. Cunn. ex F. Muell.) F. Muell. Nature, 182(4649), 1615–1616.
Grimsson, F., Grimm, G.W., & Zetter, R. (2017). Evolution of pollen morphology in Loranthaceae. Grana, 57, 16–116.
Johri, B.M., Ambegaokar, K.B., & Srivastava, P.S. (1992). Comparative embryology of angiosperms. Springer-Verlag.
Kuijt, J. (1981). A rejoinder on Oryctina (Loranthaceae). Plant Systematic and Evolution, 137, 215–219.
Kuijt, J. (2015). Santalales. In J. Kuijt & B. Hansen (Eds.), The families and genera of vascular plants, Flowering plants: Eudicots; Santalales, Balanophorales (pp. 1–189, Vol. 12). Springer.
Kuijt, J., & Graham, J.C. (2015). Two New Species of Loranthaceae from Central Peru. Novon A Journal for Botanical Nomenclature, 24, 173–178.
Lamilla, L.A., Robayo, C.A., Castaño, F., Marquínez, X., & Raz, L. (2020). Floral anatomy of Tristerix longebracteatus (Loranthaceae). Revista de Biología Tropical, 68, 87–98.
Narayana, R. (1958a). Morphological and Embryological Studies in the Family Loranthaceae - III Nuytsia floribunda (Labill) R.Br. Phytomorphology, 8, 306–323.
Narayana, R. (1958b). Morphological and embryological studies in the family Loranthaceae - Lysiana exocarpi (Behr) Van Tieghem. Phytomorphology, 15, 146–168.
Nickrent, D.L., Malécot, V., Vidal-Russell, R., & Der, J.P. (2010). A revised classification of santalales. Taxon, 59, 538–558.
Nickrent, D.L., Anderson, F., & Kuijt, J. (2019). Inflorescence evolution in Santalales: Integrating morphological characters and molecular phylogenetics. American Journal of Botany, 106(3), 402–414.
Prakash, S. (1960). Morphological and embryological studies in the family Loranthaceae - VI. Peraxilla tetrapetala (Linn. F.) van Tiegh. Phytomorphology, 10, 224–234.
Prakash, S. (1961). Morphological and Embryological Studies in the Family Loranthaceae - VII Atkinsonia Ligustrina (Cunningh) FV Muell. Phytomorphology, 11, 325–335.
Raj, B. (1970). Morphological and Embryological Studies in the Family Loranthaceae-XIII. Amylotheca dictyophleba Van Tiegh. Öesterreichische Botanische Zeitschrift, 118, 417–430.
Robayo, C.A., Marquínez, X., Raz, L., & Nickrent, D.L. (2020). Floral anatomy of the plant Psittacanthus schiedeanus (Loranthaceae). Revista de Biología Tropical, 68, 1–11.
Robles, A., Raz, L., & Marquínez, X. (2016). Anatomía floral de Peristethium leptostachyum (Loranthaceae). Revista de Biología Tropical, 64, 357–368.
Schaeppi, H. & Steindl, F. (1942). Blütenmorphologische und embryologische Untersuchungen an Loranthoideen. Vierteljahrsschr Naturf Ges Zürich, 87, 301–337.
Su, H.J., Hu, J.M., Anderson, F.E., Der, J.P., & Nickrent, D.L. (2015). Phylogenetic relationships of Santalales with insights into the origins of holoparasitic Balanophoraceae. Taxon, 64, 491–506.
Suaza-Gaviria, V., Pabón, N., & González, F. (2016). Development and morphology of flowers in Loranthaceae. International Journal of Plant Science, 177, 559–578.
Treub, M. (1883). Observations sur les Loranthacees. IV. Loranthus pentandrus L. Annales du Jardin Boanique de Buitenzorg, 3, 184–189.
Venturelli, M. (1981). Embriologia de Struthanthus vulgaris (Loranthaceae-Loranthoideae). Kurtziana, 14, 73–100.
Venturelli, M. (1983). Estudos embriológicos em Loranthaceae: Gênero Tripodanthus. Kurtziana, 16, 71–90.
Vidal-Russell, R., & Nickrent, D.L. (2008a). Evolutionary relationships in the showy mistletoe family (Loranthaceae). American Journal of Botany, 95, 1015–1029.
Vidal-Russell, R., & Nickrent, D.L. (2008b). The first mistletoes: Origins of aerial parasitism in Santalales. Molecular Phylogenetic and Evolution, 47, 523–537.
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