The stigma of Ornithogalum sigmoideum is of dry and papillate type. The papillae are covered by a cuticle-pellicle layer, as revealed by staining. The activity of nonspecific esterase, acid phosphatase and peroxidase increases in the pellicle during the receptivity period. The style of O. sigmoideum is of the hollow type. Ultrastructural study of the cells lining the canal indicated that they are secretory cells and contain abundant endoplasmic reticulum, dictyosomes, mitochondria, plastids and ribosomes. After anthesis these organelles show degeneration at the end of the secretory phase. In canal cells, cytochemical tests showed the presence of acidic polyanions, insoluble and acidic polysaccharides, proteins and lipids. Before anthesis the canal cells are rich in polysaccharides, proteins and lipids. At maturity the cuticle is ruptured and secretory materials from the canal cells are released into the canal. In the unpollinated style of O. sigmoideum the exudates accumulated in the center of the canal; in pollinated pistils the same secretion materials were dispersed through the canal, which became wider.
BIRECKA H, BRIBER A, and CATALFAMO JL. 1973. Comparative studies on tobacco pith and sweet potato root isoperoxidases in relation to injury, indolacetic acid and ethylene effects. Plant Physiology 52: 43-49.
CHEUNG AY. 1996. The pollen tube growth pathway: Its molecular and biochemical contributions and responses to pollination. Sexual Plant Reproduction 9 (6): 330-336.
CIAMPOLINI F, CRESTI M, SARFATTI G, and TIEZZI A. 1981. Ultrastructure of the stylar canal cells of Citrus limon (Rutaceae). Plant Systematics and Evolution 130: 263-274.
CIAMPOLINI F, SHIVANNA KR, and CRESTI M. 1988. The structure and cytochemistry of the pistil of Hypericum calycinum: Style. Sexual Plant Reproduction 1: 248-255.
CIAMPOLINI F, SHIVANNA KR, and CRESTI M. 1990. The structure and cytochemistry of the pistil of Sternbergia lutea (Amaryllidaceae). Annals of Botany 66: 703-712.
CIAMPOLINI F, and CRESTI M. 1997. Ultrastructural observations of stigmatic style of Corylus avellana. Atti Accademia Fisiocritici Siena 16: 73-74.
CLARKE AE, CONSODINE JA, WARD R, and KNOX RB. 1977. Mechanism of pollination in Gladiolus: Roles of stigma and pollen tube guide. Annals of Botany 41: 15-20.
DAFNI A, and MOTTE MAUES M. 1998. A rapid and simple procedure to determine stigma receptivity. Sexual Plant Reproduction 11: 177-180.
DICKINSON HG, MORIARTY J, and LAWSON J. 1982. Pollen pistil interaction in Lilium longiflorum: The role of the pistil in controlling pollen tube growth following cross and selfpollinations. Proceedings of the Royal Society of London. Series B 215: 45-62.
DUPUIS I, and DUMAS C. 1990. Biochemical markers of female receptivity in Maize (Zea mays L.) assessed using in vitro fertilization. Plant Science 70: 11-20.
FEDER N, and O'BRIEN TP. 1968. Plant microtechnique: Some principles and new methods. American Journal of Botany 55: 123-142.
GHOSH S, and SHIVANNA KR. 1980. Pollen-pistil interaction in Lilium grandiflorum: Scanning electron microscopic observations and proteins of the stigma surface. Planta 149: 257-261.
GHOSH S, and SHIVANNA KR. 1984. Structure and cytochemistry of the stigma and pollen-pistil interaction in Zephyranthes. Annals of Botany 53: 91-105.
GOMORI G. 1941. Distribution of acid phosphatase in the tissues under normal and under pathologic conditions. Archives of Pathology 32:189-199.
GOMORI G. 1950. An improved histochemical technique for acid phosphatase. Stain Technology 25:81-85.
HESLOP-HARRISON J. 1979. Aspects of the structure, cytochemistry and germination of the pollen of rye (Secale cereale L.). Annals of Botany 44: 1-47.
HESLOP-HARRISON J, HESLOP-HARRISON Y, KNOX RB, and HOWLETT B. 1973. Pollen wall proteins: Gametophytic and sporophytic fractions in the pollen walls of the Malvaceae. Annals of Botany 37: 403-412.
HESLOP-HARRISON Y, and SHIVANNA KR. 1977. The receptive surface of the angiosperm stigma. Annals of Botany 41:1233-1258.
HISCOCK SJ, HOEDEMAEKERS K, FRIEDMAN WE, and DICKINSON HG. 2002. The stigma surface and pollen-stigma interactions in Senecio squalidus L. (Asteraceae) following cross (compatible) and self (incompatible) pollinations. International Journal of Plant Sciences 163: (1)1-16.
JAUH GY, and LORD EM. 1996. Localization of pectins and arabinogalactan proteins in lily (Lilium longiflorum L.) pollen tube and style and their possible roles in pollination. Planta 199: 251-261.
JAUH GY, ECKARD KJ, NOTHNAGEL EA, and LORD EM. 1997. Adhesion of lily pollen tubes on an artificial matrix. Sexual Plant Reproduction 10: 173-180.
KANDASAMY MK, and KRISTEN U. 1987. Developmental aspects of ultrastructure, histochemistry and receptivity of the stigma of Nicotiana sylvestris. Annals of Botany 60: 427-437.
KENRICK J, and KNOX RB. 1981. Post-pollination exudates from stigmas of Acacia (Mimosaceae). Annals of Botany 48: 103-106.
KULLONI SK, RAMASUBBO R, SREEKALA AK, and PANDURANGAN AG. 2010. Cytochemical localization of stigma-surface esterases in three species of Impatiens (Balsaminaceae) of Western Ghats. Asian Journal of Experimental Biological Sciences 1 (1): 106-111.
LOEWUS F, and LABARCA C. 1973. Pistil secretion product and pollen tube wall formation. In: Biogenesis of Plant Cell Wall Polysaccharides, 125-193. Loewus, New York, London.
MATTSSON O, KNOX RB, HESLOP-HARRISON J, and HESLOPHARRISON Y. 1974. Protein pellicle of stigmatic papillae as a probable recognition site in incompatibility reactions. Nature 247: 298-300.
MAYER JL, and PICKERSGILL B. 1990. Stigma morphology and pollination in Arachis L. Annals of Botany 66: 73-82.
MCINNIS SM, EMERY DC, PORTER R, DESIKAN R, HANCOCK JT, and HISCOCK SJ. 2006. The role of stigma peroxidases in flowering plants: Insights from further characterization of a stigma-specific peroxidase (SSP) from Senecio squalidus (Asteracea). Journal of Experimental Botany 57 (8): 1835-1846.
PEARSE AGE. 1961. Histochemistry. Theoretical and Applied. 2nd ed. Boston: Little, Brown &Co. RAGHAVAN V. 1997. Pollination and fertilization-stigma, style and pollen-pistil interaction. In: Molecular Embryology of Flowering Plants, 181-201. Cambridge University Press.
ROSEN WG, and THOMAS HR. 1970. Secretory cells of lily pistils. I. Fine structure and function. American Journal of Botany 57: 114-118.
SEYMOUR R, and BLAYLOCK AJ. 2000. Stigma peroxidase activity in association with thermogenesis in Nelumbo nucifera. Aquatic Botany 67: 155-159.
SHIVANNA KR, and JOHRI BM. 1985. Pollen pistil interaction. In: The Angiosperm Pollen. 163-197. New Delhi.
STPICZYNSKA M. 2003. Stigma receptivity during the life span of Platanthera chlorantha Custer (Rchb) Flowers. Acta Biologica Cracoviensia Series Botanica 45: 37-41.
TANDON R, MANOHARA TN, NIJALINGAPPA BHM, and SHIVANNA KR. 2001. Pollination and pollen-pistil interaction in oil palm, Elaeis guineensis. Annals of Botany 87: 831-838.
TILTON VR, and HORNER HT. 1980. Stigma, style and obturator of Ornithogalum caudatum (Liliaceae) and their function in the reproductive process. American Journal of Botany 67 (7): 1113-1131.
VASILEV AE. 1970. Ultrastructure of stigmatoid cells in Lilium. Soviet Plant Physiology 17: 1035-1044.
VITHANAGE HIMV. 1984. Pollen stigma interactions: Development and cytochemistry of stigma papillae and their secretion in Annona squamosa L. (Annonaceae). Annals of Botany 54: 153-167.