Nectar resorption and translocation in Cucurbita pepo L. and Platanthera chlorantha Custer (Rchb.).

Nectar resorption and sugar translocation were studied in Cucurbita pepo (Cucurbitaceae) and Platanthera chlorantha (Orchidaceae) by micro-autoradiography. In both species, nectar was resorbed in pollinated and unpollinated flowers and ovules developing into seeds were found to be the main sugar sink. In C. pepo, the mobility of resorbed sugars in pollinated female flowers was higher than in unpollinated ones; male flowers showed lower mobility of resorbed sugar. In P. chlorantha, radioactivity was detected in pollinated flowers below and above labelled unpollinated ones: the nearer the flower, the stronger the accumulation of label in developing fruits.

[1]  P. Wittich,et al.  Sucrose utilization during ovule and seed development ofGasteria verrucosa (Mill.) H. Duval as monitored by sucrose synthase and invertase localization , 1999, Protoplasma.

[2]  G. Heinrich.  Über den Glucose-Metabolismus in Nektarien zweierAloe-Atten und über den Mechanismus der Pronektar-Sekretion , 1975, Protoplasma.

[3]  Y. Hao,et al.  Nectar production and transportation in the nectaries of the female Cucumis sativus L. flower during anthesis , 2004, Protoplasma.

[4]  M. Stpiczyńska.  Incorporation of [3H]sucrose after the resorption of nectar from the spur of Platanthera chlorantha (Custer) Rchb. , 2003 .

[5]  A. Bel,et al.  The phloem, a miracle of ingenuity , 2003 .

[6]  Wolf B. Frommer,et al.  Phloem loading and unloading of sugars and amino acids , 2003 .

[7]  M. Stpiczyńska.  Nectar resorption in the spur of Platanthera chlorantha Custer (Rchb.) Orchidaceae – structural and microautoradiographic study , 2003, Plant Systematics and Evolution.

[8]  L. Galetto,et al.  Differential nectar production between male and female flowers in a wild cucurbit: Cucurbita maxima ssp. andreana (Cucurbitaceae) , 2002 .

[9]  A. Davis,et al.  Temporal changes in floral nectar production, reabsorption, and composition associated with dichogamy in annual caraway (Carum carvi; Apiaceae). , 2002, American journal of botany.

[10]  M. Nepi,et al.  Nectar Secretion, Reabsorption, and Sugar Composition in Male and Female Flowers of Cucurbita pepo , 2001, International Journal of Plant Sciences.

[11]  L. Galetto,et al.  Patterns and implications of floral nectar secretion, chemical composition, removal effects and standing crop in Mandevilla pentlandiana (Apocynaceae) , 1998 .

[12]  H. Koopowitz,et al.  Postpollination nectar reabsorption in the African epiphyte Aerangis verdickii (Orchidaceae). , 1998, American journal of botany.

[13]  A. Davis.  Influence of floral visitation on nectar-sugar composition and nectary surface changes in Eucalyptus , 1997 .

[14]  G. Rivera,et al.  Nectar secretion pattern, removal effects, and breeding system of Ligaria cuneifolia (Loranthaceae) , 1996 .

[15]  M. Nepi,et al.  Development and Ultrastructure of Cucurbita pepo Nectaries of Male Flowers , 1996 .

[16]  M. Willemse,et al.  Nectary biology of Cucurbita pepo: ecophysiological aspects. , 1996 .

[17]  E. P. McDonald,et al.  PHOTOSYNTHESIS AND CARBON ALLOCATION IN TIPULARIA DISCOLOR (ORCHIDACEAE), A WINTERGREEN UNDERSTORY HERB , 1995 .

[18]  S. Nicolson.  Direct demonstration of nectar reabsorption in the flowers in Grevillea robusta (Proteaceae) , 1995 .

[19]  L. Galetto,et al.  Reproductive biology, variability of nectar features and pollination of Combretum fruticosum (Combretaceae) in Argentina , 1994 .

[20]  G. Pyke.  What does it cost a plant to produce floral nectar? , 1991, Nature.

[21]  A. Búrquez,et al.  Do flowers reabsorb nectar , 1991 .

[22]  C. Schlichting,et al.  Evidence for Non-Random Fertilization in the Common Zucchini, Cucurbita pepo , 1988 .

[23]  E. Southwick.  Photosynthate Allocation to Floral Nectar: A Neglected Energy Investment , 1984 .

[24]  R. Bieleski,et al.  Sorbitol metabolism in nectaries from flowers of Rosaceae , 1980 .

[25]  A. Fahn,et al.  An Autoradiographical Study of Nectar Secretion in Lonicera japonica Thunb , 1975 .

[26]  P. Leeuwangh,et al.  TRANSLOCATION OF ASSIMILATES IN FRITILLARIA IMPERIALIS L. 1. THE SECRETION OF 14C-LABELLED SUGARS BY THE NECTARIES IN RELATION TO PHYLLOTAXIS , 1970 .

[27]  E. Reynolds.  THE USE OF LEAD CITRATE AT HIGH pH AS AN ELECTRON-OPAQUE STAIN IN ELECTRON MICROSCOPY , 1963, The Journal of cell biology.

[28]  R. Shuel.  Influence of reproductive organs on secretion of sugars in flowers of Streptosolen jamesonii, Miers. , 1961, Plant physiology.

[29]  M. W. Pedersen,et al.  Absorption of C 14 -Labeled Sucrose by Alfalfa Nectaries , 1958, Science.