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'Fagaceae' in keywords
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1993 (1)
1992 (2)
1979 (1)
1Author    Z. NaturforschRequires cookie*
 Title    On the Pigmentation of the Pollen of  
 Abstract    N o th o fa ­ g u s a n ta rc tic a (Forst.) Oerst. (Fagaceae) E ckhard W ollenw eber Extraction o f pollen o f N othofagus antarctica with acid hydrolysis yields kaem pferol, quercetin, the rare flavonol sexangularetin, and naringenin. The tetrahydroxy-chalcone isosalipurpol is shown for the first tim e to occur in such high amount as free aglycone in mature pollen; it yields na­ ringenin in usual extraction procedures. The bright yellow coloration o f the pollen is due to the presence o f isosalipur­ pol and sexangularetin. 
  Reference    Z. Naturforsch. 34c, 1289 (1979); received Septem ber 4 1979 
  Published    1979 
  Keywords    Nothofagus antarctica, Fagaceae, Pollen, Pigmentation, Rare Flavonoids 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-1289_n.pdf 
 Identifier    ZNC-1979-34c-1289_n 
 Volume    34 
2Author    P.-G Gülz, G. BoorRequires cookie*
 Title    Seasonal Variations in Epicuticular Wax Ultrastructures of Quercus robur Leaves  
 Abstract    Already the very young leaflets of oak (Quercus robur L.), newly emerging from their buds, are covered by a thin wax layer, but at this time it lacks any wax sculptures or crystalloids. Both in its amount and its composition this wax layer is quite different to that of mature leaves. After leaf unfolding a dynamic biosynthesis of wax lipids is started. Ten days after the leaf has emerged from its bud, wax crystalloids are seen for the first time, developing out of the wax layer in the form of platelets. These crystalloids increase in size and quantity within the next weeks and are present on both leaf surfaces. On the adaxial side a dense and uniform arrangement of fringed edged platelets is observed. Similar dense arrangements of platelets are found on the abaxial leaf side, but with an intensive concentration and orientation around the stomata. All platelets are composed of tetracosanol, the main wax component, accounting for more than 40% of wax. Variations in surface wax ultrastructures are observed in July. Well formed platelets and melted away crystalloids are found close together in distinct parts of the same leaf, both on the adaxial and on the abaxial sides of the leaf. These observations pertain to preparations made from July to November with a trend toward recrystallization in October. High temperature and essential oils may be the reasons for the melting away or solution of the platelets. 
  Reference    Z. Naturforsch. 47c, 807—814 (1992); received June 9 1992 
  Published    1992 
  Keywords    Quercus robur, Fagaceae, Leaves, Wax Ultrastructure, Seasonal Variations 
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 TEI-XML for    default:Reihe_C/47/ZNC-1992-47c-0807.pdf 
 Identifier    ZNC-1992-47c-0807 
 Volume    47 
3Author    P.-G Gülz, E. MüllerRequires cookie*
 Title    Seasonal Variation in the Composition of Epicuticular Waxes of Quevcus robur Leaves  
 Abstract    The epicuticular leaf waxes of Quercus robur were analyzed continuously over a two years vegetation period with preparation every week from April to November. The folded leaflets in buds have waxes quite different in yield and composition from those of mature leaves. They contain homologous series of hydrocarbons, wax esters, primary alco­ hols, fatty acids and triterpenoids from the beginning, but not aldehydes. After leaf unfolding a dynamic biosynthesis of alcohols, aldehydes and fatty acids is observed in May and June. Wax content is doubled per dry weight or in cm2 leaf surface area and 80-fold per one leaf in that time. During leaf development tetracosanol becomes the dominant epicuticular wax component comprising ca. 40% of the wax. In both years of the study a reactivation of wax ester biosynthesis is observed in October and November. Esters with chain length C36 and C38 increased particularly. From July to November the wax composition remained nearly constant within mean values and their stand­ ard deviations. Within the two years studied most values concerning wax composition are reproducible and are therefore genetically determined. In spring the growing processes are influenced by climatic factors. 
  Reference    Z. Naturforsch. 47c, 800—806 (1992); received June 9 1992 
  Published    1992 
  Keywords    Quercus robur, Fagaceae, Leaves, Epicuticular Wax Composition, Seasonal Variation 
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 TEI-XML for    default:Reihe_C/47/ZNC-1992-47c-0800.pdf 
 Identifier    ZNC-1992-47c-0800 
 Volume    47 
4Author    Z. NaturforschRequires cookie*
 Title    Glandular Trichomes and the Yolatiles Obtained by Steam Distillation of Quercus robur Leaves  
 Abstract    R a lf E n g e lb, P a u l-G e rh a rd G ü lz 3, T h o rs te n H e rrm a n n 3, a n d A d o lf N a h r s te d tb G landular trichom es in form of long stretched tubes are present on the low er leaf side of Quercus robur as shown by scanning electron microscopy. The glands contain an essential oil, which was isolated by steam distillation together with volatile waxy com ponents of the leaves in an am ount of 0.025% of fresh leaves. The product of steam distillation was analyzed by GC-MS. Identification of com pounds is based on comparison of their mass spectral data with those of authentic samples in com bination with retention indices and MS data using the SeKoMS (Search Kovats Indices and Mass Spectra) Library. A ltogether 184 com ponents of the product of steam distillation were separated, 155 of which could be identified, another 7 were tentatively assigned. T hree groups of substances according to their chemical com posi­ tion are found: hexenyl derivatives and some acetals (32%); terpenes including m onoterpenes (4%), sesquiterpenes and diterpenes (21%); and alkane derivatives (35%). The residual 8% consist of benzyl alcohol, com pounds which stem from the degradation of carotenes, and mis­ cellaneous constituents. 
  Reference    Z. Naturforsch. 48c, 736—744 (1993); received July 231993 
  Published    1993 
  Keywords    Quercus robur, Fagaceae, G landular Trichomes, Steam Distillation, Volatiles 
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 TEI-XML for    default:Reihe_C/48/ZNC-1993-48c-0736.pdf 
 Identifier    ZNC-1993-48c-0736 
 Volume    48