Floral function in relation to floral structure in two Periploca species (Periplocoideae) Apocynaceae

This study comprises an investigation into the floral function in relation to the floral structure of Periploca aphylla and P. Angustifolia, using light and scanning electron microscopy. Both species display the following floral structures: style-head bearing pollen translators, shelf-like nectaries, staminal feet, nectar-collecting troughs, trisegmented corolline corona lobes and corolla lobes, and anthers and nectaries covered by unicellular hairs. Lateral segments of adjacent corona lobes are fused with half of the adaxial base of the adjacent corolla lobes, creating openings through which pollinators can reach the nectar-collecting troughs in the corolla base. Flowers are rotate with spreading corolla lobes and exposed gynostegium, thus sorting in the open-access fly pollination system. The following features are useful to distinguish the flowers of the two species: corolla color, presence or absence of long unicellular hairs and white spots size on the adaxial surface of corolla lobes, translator length, pollen tetrads color, and presence or absence of linear tetrads. It seems that the floral modifications of the two Periploca species serve to optimize pollination efficiency by attracting a wide number of pollinators, thus enhancing the pollination success of plants.

Anahtar Kelimeler:

Corolline corona, nectar trough, open-access pollination, pollen tetrads, shelf-like nectaries, spathulate translators, staminal feet

Floral function in relation to floral structure in two Periploca species (Periplocoideae) Apocynaceae

Keywords:

Corolline corona, nectar trough, open-access pollination, pollen tetrads, shelf-like nectaries, spathulate translators, staminal feet,

PDF

___

Almeida, OJGd, Paoli, AAS, Cota-Sánchez, JH (2012). A macro- and micromorphological survey of floral and extrafloral nectaries in the epiphytic cactus Rhipsalis teres (Cactoideae: Rhipsalideae). Flora 207: 119–125.
Blume CL (1828). [Preface material]. Pp. i-x.In: Blume CL, Fischer JB, editors. Flora Javae. Brussels.
Brown R (1810). On the Asclepiadeae, a natural order of plants separated from the Apocineae of Jussieu. London.
Bookman SS (1981). The floral morphology of Asclepias speciosa (Asclepiadaceae) in relation to pollination and a clarification in terminology for the genus. Amer J Bot 68: 675–679.
Browicz K (1966). The genus Periploca L. A monograph. Arboretum Kórnickie 11: 4–104.
Bruyns PV (2000). Phylogeny and biogeography of the Stapeliads 1. Phylogeny. Plant Syst Evol 221: 199–226.
Corgan JN, Widmoyer FB (1971). The effect of gibberellic acid on flower differentiation, date of bloom, and flower hardiness of peach. J Amer Soc Sci 96: 54–57.
Dane F (2000). In situ germination of pollen tetrads in Periploca graceae L. (Periplocaceae). Turk J Biol 24: 337–343.
Endress ME (2001). Apocynaceae and Asclepiadaceae: united they stand. Haseltonia 8: 2–9.
Endress ME, Bruyns PV (2000). A revised classification of the Apocynaceae s.l. Bot Review 66: 1–56.
Endress PK (1994). Diversity and Evolutionary Biology of Tropical Flowers. Cambridge, UK: Cambridge University Press.
Erdtman G (1960). The acetolysis method. A revised description. Svensk Bot Tidsk 54: 561–564.
Ionta GM, Judd WS (2007). Phylogenetic relationships in Periplocoideae (Apocynaceae s.l.) and insights into the origin of Pollinia. Ann Missouri Bot Gard 94: 360–375.
Johanson DA (1940). Plant Microtechnique. New York, NY, USA: McGraw-Hill Book Co.
Jonkers HA (1993). De bestuivers van succulenten. Succulenta 72: 268–275 (in Dutch).
Kevan PG, Eisikowitch D, Rathwell B (1989). The role of nectar in the germination of pollen in Asclepias syriaca L. Bot Gaz 150: 266–270.
Klackenberg J (1999). Revision of the Malagasy genera Pentopetia and Ischnolepis (Apocynaceae s.l., Periplocoideae). Candollea 54: 257–339.
Kunze H (1990). Morphology and evolution of the corona in Asclepiadaceae and related families. Trop Subtrop Pflanzenwelt 76: 1–51.
Kunze H (1991). Structure and function in asclepiad pollination. Pl Syst Evol 176: 227–253.
Kunze H (1993). Evolution of the translator in Periplocaceae and Asclepiadaceae. Pl Syst Evol 185: 99–122.
Kunze H (2005). Morphology and evolution of the corolla and corona in the Apocynaceae s.l. Bot Jahr Syst 126: 347–383.
Liede S, Kunze H (1993). A descriptive system for corona analysis in Asclepiadaceae and Periplocaceae. Pl Syst Evol 185: 275–284.
Linnaeus C (1753). Species Plantarum, vol. 1. Holmiae, Stockholm, pp. 560.
Linnaeus C (1754). Genera Plantarum, ed. 5. Stockholm.
Nishino E (1982). Corolla tube formation in six species of Apocynaceae. Bot Mag (Tokyo) 95: 1–17.
Nocentini, D, Pacini, E, Massimo Guarnieri, M, Nepi, M (2012). Flower morphology, nectar traits and pollinators of Cerinthe major (Boraginaceae-Lithospermeae). Flora 207: 186–196.
Ollerton J, Liede S (1997). Pollination systems in the Asclepiadaceae: a survey and preliminary analysis. Biol J Linnean Soc 62: 593– 610.
Pisciotta S, Raspi A, Sajeva M (2011). First records of pollinators of two co-occurring Mediterranean Apocynaceae. Plant Biosystems 145: 141–149.
Safwat FM (1962). The floral morphology of Secamone and the evolution of the pollinating apparatus in Asclepiadaceae. Ann Missouri Bot Gard 49: 95–129.
Schick B (1982). Zur Morphologie, Entwicklung, Feinstruktur und Funktion des Translators von Periploca L. (Asclepiadaceae). In: Rauh W, editor. Akademie der Wissenschaften und der Literatur. Trop Subtrop Pflanzenwelt 40: 515–553 (in German).
Schill R, Jäckel U (1978). Beitrag zur Kenntnis der Asclepiadaceen- Pollinarien. Trop Subtrop Pflanzenwelt 22: 1–122 (in German).
Sennblad B, Endress ME, Bremer B (1998). Morphology and molecular data in phylogenetic fraternity-The tribe Wrightieae (Apocynaceae) revisited. Amer J Bot 85:1143–1158.
Venter HJT (1997). A revision of Periploca (Periplocaceae). South African Journal of Botany 63: 123–128.
Venter HJT, Verhoeven RL (1997). Nektarien und ihre Ökologische Bedeutung. Taxon 46: 705–720.
Venter HJT, Verhoeven RL (2001). Diversity and relationships within the Periplocoideae (Apocynaceae). Ann Missouri Bot Gard 88: 550–568.
Verhoeven RL, Venter HJT (1994). Pollen morphology of Periploca (Periplocaceae). South African Journal of Botany 60: 198–202.
Verhoeven RL, Venter HJT (1997). The translator of Raphionacme (Periplocaceae). South African Journal of Botany 63: 46–54.
Verhoeven RL, Venter HJT (2001). Pollen morphology of the Periplocoideae, Secamonoideae, and Asclepiadoideae (Apocynaceae). Ann Missouri Bot Gard 88: 569–582.
Vogel S (1977). Nektarien und ihre Ökologische Bedeutung. Apidologie 8: 321–335 (in German).
Zito P, Sajeva M, Bruno M, Rosselli S, Maggio A, Senatore F (2013). Essential oils composition of Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf (Apocynaceae – Periplocoideae). Nat Prod Res 27: 255–265.
Zito P, Sajeva M (2012). Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf on Lampedusa Island. Asklepios 113: 3–15.