Skip to main content
Log in

Structure, ultrastructure, and histochemistry of the pollen tube pathway in the milkweed Asclepias exaltata L.

  • Original Paper
  • Published:
Sexual Plant Reproduction Aims and scope Submit manuscript

Abstract

The structure of the gynoecium and pollen tube pathway in unpollinated and pollinated carpels of Asclepias exaltata L. has been characterized. Pollen tubes penetrate a dry-type stigma, grow intercellularly in a core of solid tissue in the upper style, and subsequently traverse a hollow stylar canal to the ovary where they grow across the placental epithelium to the ovule micropyles. The fine structural characteristics of transmitting cells of the solid style, stylar canal, and placental epithelium indicate a secretory function. Extracellular secretions staining positively for proteins, insoluble carbohydrates, and arabinogalactans/arabinogalactan proteins are present in the solid style, hollow stylar canal, ovary, and micropyle. Micropylar exudate is present subtending the extended cuticle of the embryo sac adjacent to the filiform apparatus of the synergids, providing ultrastructural evidence for a secretion arising from the angiosperm embryo sac.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Brown R (1833) On the organs and mode of fecundation in Orchideae and Asclepiadeae. Trans Linn Soc (Lond) 16:685–745

    Google Scholar 

  • Broyles SB, R Wyatt (1993) The consequences of self-pollination in Asclepias exaltata, a self-incompatible milkweed. Am J Bot 80:41–44

    Google Scholar 

  • Bruun L, Olesen P (1989) A structural investigation of the ovule in sugar beet, Beta vulgaris: the micropylar nucellus. Nord J Bot 9:81–87

    Google Scholar 

  • Chao CY (1971) A periodic acid-Schiff's substance related to the directional growth of pollen tube into embryo sac in Paspalum ovules. Am J Bot 58:649–654

    Google Scholar 

  • Christ VP, Schnepf E (1988) Zur Struktur und Funktion von Asclepiadaceen-Nektarien. Beitr Biol Pflanz 63:55–79

    Google Scholar 

  • Corry TH (1883a) On the mode of development of the pollinium in Asclepias cornuti Decaisne. Trans Linn Soc Lond Ser 2 Bot:75–84

    Google Scholar 

  • Corry TH (1883b) On the structure and development of the gynostegium and the mode of fertilization in Asclepias cornuti Decaisne (A. syriaca L.) Trans Linn Soc Lond Ser 2 Bot: 173–207

  • Endress PK (1980) Ontogeny, function and evolution of extreme floral construction in Monimiaceae. Plant Syst Evol 134:79–120

    Google Scholar 

  • Endress PK (1982) Syncarpy and alternative modes of escaping disadvantages of apocarpy in primitive angiosperms. Taxon 3:48–52

    Google Scholar 

  • Fisher DB (1968) Protein staining of ribboned epon sections for light microscopy. Histochemie 16:92–96

    Google Scholar 

  • Franssen-Verheijen MAW, Willemse MTM (1993) Micropylar exudate in Gasteria (Aloaceae) and its possible function in pollen tube growth. Am J Bot 80:253–262

    Google Scholar 

  • Galil J, Zeroni M (1965) Nectar system of Asclepias curassavica. Bot Gaz 126:144–148

    Google Scholar 

  • Gurr E (1965) The rational use of dyes in biology. Hill, London

    Google Scholar 

  • Heslop-Harrison J, Shivanna K (1977) The receptive surface of the angiosperm stigma. Ann Bot 41:1233–1238

    Google Scholar 

  • Heslop-Harrison Y, Heslop-Harrison J, Reger BJ (1985) The pollen-stigma interaction in the grasses. 7. Pollen-tube guidance and the regulation of tube number in Zea mays L. Acta Bot Neerl 34:193–211

    Google Scholar 

  • Jensen WA (1962) Botanical histochemistry: principles and practice. Freeman, London

    Google Scholar 

  • Kaul V, Rouse JL, Williams EG (1986) Early events in the embryo sac after intraspecific and interspecific pollinations in Rhododendron kawakamii and R. retusum. Can J Bot 64:282–291

    Google Scholar 

  • Kephart SR (1981) Breeding systems in Asclepias incarnata L., A. syriaca L., and A. verticillata L. Am J Bot 68:226–232

    Google Scholar 

  • 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

    Google Scholar 

  • Knox RB (1984) Pollen-pistil interactions. Annu Rev Plant Physiol 17:508–608

    Google Scholar 

  • O'Brien TP, McCully ME (1981) The study of plant structure: principles and selected methods. Termarcarphi, Victoria, Australia

    Google Scholar 

  • Plotnikova T (1938) An experiment in self-pollination of Asclepias cornuti (in Russian, English summary). Ukrains'ka Akademiia nauk, Inst Bot Zh 26–27

  • Queller DC (1985) Proximate and ultimate causes of low fruit production in Asclepias exaltata. Oikos 44:373–381

    Google Scholar 

  • Reger BJ, R Chaubal, R Pressey (1992) Chemotropic responses by pearl millet pollen tubes. Sex Plant Reprod 5:47–56

    Google Scholar 

  • Reynolds ES (1963) The use of lead citrate at high pH as an electron opaque stain in electron microscopy. J Cell Biol 17:208–212

    Article  CAS  PubMed  Google Scholar 

  • Sage TL, Broyles SB, Wyatt R (1990) The relationship between the five stigmatic chambers and two ovaries of milkweed (Asclepias amplexicaulis sm.) flowers: a three-dimensional assessment. Isr J Bot 39:187–196

    Google Scholar 

  • Sanders LC, Lord EM (1992) A dynamic role for the stylar matrix in pollen tube extension. Int Rev Cytol 140:297–318

    Google Scholar 

  • Schnepf E, Christ P (1980) Unusual transfer cells in the epithelium of the nectaries of Asclepias curassavica L. Protoplasma 105:135–148

    Google Scholar 

  • Sparrow FK, Pearson NL (1948) Pollen compatibility in Asclepias syriaca. J Agric Res 77:187–199

    Google Scholar 

  • Spurr AR (1969) A low-viscosity epoxy resin embedding medium for electron microscopy. J Ultrastruct Res 26:31–43

    CAS  PubMed  Google Scholar 

  • Staehelin LA, Chapman RL (1987) Secretion and membrane recycling in plant cells: novel intermediary structures visualized in ultrarapidly frozen sycamore and carrot suspension-culture cells. Planta 171:43–57

    Google Scholar 

  • Stevens OA (1945) Cultivation of milkweeds. N D Agric Exp Stn Bull 333:1–19

    Google Scholar 

  • Tilton V (1980) The nucellar epidermis and micropyle of Ornithogalum caudatum (Liliaceae) with a review of these structures in other taxa. Can J Bot 58:1872–1884

    Google Scholar 

  • Webb MC, Williams EG (1988) The pollen tube pathway in the pistil of Lycopersicon peruvianum. Ann Bot 61:415–423

    Google Scholar 

  • Wyatt R (1976) Pollination and fruit-set in Asclepias: a reappraisal. Am J Bot 63:845–851

    Google Scholar 

  • Wyatt R, Broyles SB (1994) Ecology and evolution of reproduction in milkweeds. Annu Rev Ecol Syst 25:423–441

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Sage, T.L., Williams, E.G. Structure, ultrastructure, and histochemistry of the pollen tube pathway in the milkweed Asclepias exaltata L.. Sexual Plant Reprod 8, 257–265 (1995). https://doi.org/10.1007/BF00229381

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00229381

Key words

Navigation