caa a22 4500 477053017 CHVBK 20180405111342.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF02441957 doi (NATIONALLICENCE)springer-10.1007/BF02441957 Pacini E. Botany Section, Department of Environmental Biology, University of Siena, Via P. A. Mattioli 4, I-53100, Siena, Italy aut Types and meaning of pollen carbohydrate reserves [Elektronische Daten] [E. Pacini] During pollen development, soluble carbohydrates of sporophytic origin may be consumed immediately, polymerized to form starch reserves or intine, or transformed into other molecules. Disregarding intine, in mature pollen there are three different types of carbohydrates: (1) polysaccharides such as starch in amyloplasts or polysaccharides in cytoplasmic vesicles, (2) disaccharides such as sucrose and (3) monosaccharides such as glucose and fructose. At dispersal, pollen may be partly or slightly dehydrated, or not dehydrated at all. Partly dehydrated pollen has the capacity to lose or acquire water within limits without detriment to its viability. Slightly and non-dehydrated pollen is vulnerable to water loss and quickly becomes inviable. In partly dehydrated of pollen the carbohydrates consist of cytoplasmic polysacharides and sucrose; in slightly and non-dehydrated pollen these are absent or in low concentrations but there may be reserves of cytoplasmic callose. Starch, glucose and fructose are found in both types. It is postulated that cytoplasmic carbohydrates and sucrose are involved in protecting pollen viability during exposure and dispersal. Springer-Verlag, 1996 Starch nationallicence Cytoplasmic polysaccharides nationallicence Sucrose nationallicence Pollen water content nationallicence Viability nationallicence Sexual Plant Reproduction Springer-Verlag 9/6(1996-11-01), 362-366 0934-0882 9:6<362 1996 9 497 https://doi.org/10.1007/BF02441957 text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02441957 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Pacini E. Botany Section, Department of Environmental Biology, University of Siena, Via P. A. Mattioli 4, I-53100, Siena, Italy aut NATIONALLICENCE 773 0- Sexual Plant Reproduction Springer-Verlag 9/6(1996-11-01), 362-366 0934-0882 9:6<362 1996 9 497 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer