Botanisches Institut der Universität zu Köln, Gyrhofstraße 15, D-5000 Köln 41 Z. Naturforsch. 40c, 599—605 (1985); received May 6, 1985 Epicuticular Waxes, Alpine Plants, Ecophysiology, Relation to Altitude, Ultrastructure Epicuticular waxes were extracted and analysed from leaves of 7 different high alpine plant species, with 3 species harvested at different altitudes: Salix herbacea (1950 m, ...

in order to evaluate the effect of terminal water deficit stress on leaf traits and their relations to grain yield in different barley genotypes (‘yousof’, ‘fajr30’, ‘nosrat’, ‘pbyt-46’, ‘pbyt-97’ and ‘morocco’), two separated experiments were conducted in stress (water withholding from anthesis towards the end of growing season), and non stress (normal irrigation) conditions based on rcbd with...

BACKGROUND AND AIMS Only few data on the epicuticular waxes (EWs) of horsetails are available. This contribution therefore focuses on the wax micromorphology and chemical composition of Equisetum species of the subgenera Equisetum and Hippochaete. METHODOLOGY Distribution patterns and structural details of EW on the shoots were studied by scanning electron microscopy. After extraction with ch...

For plant pathogenic fungi, such as powdery mildews, that survive only on a limited number of host plant species, it is a matter of vital importance that their spores sense that they landed on the right spot to initiate germination as quickly as possible. We investigated a barley (Hordeum vulgare) mutant with reduced epicuticular leaf waxes on which spores of adapted and nonadapted powdery mild...

Plant surfaces showing hierarchical structuring are frequently found in plant organs such as leaves, petals, fruits and stems. In our study we focus on the level of cell shape and on the level of superimposed microstructuring, leading to hierarchical surfaces if both levels are present. While it has been shown that epicuticular wax crystals and cuticular folds strongly reduce insect attachment,...

The wood protective action of citrus wax, a waste from the citrus industry that is a mixture of citrus fruit epicuticular waxes and essential oils, was evaluated against the termite Cryptotermes brevis Walker (Isoptera: Kalotermitidae). The antifeedant index (AI) of the total wax and fractions was calculated. The total citrus wax exhibited an AI₅₀ value of 24.69 mg/cm³, the wax after hydrodisti...

The spectral reflectance and transmittance over the wavelength range of 250–700 nm were evaluated for leaves of 20 deciduous tree species and leaf sheaths of five isogenic wax variants of Sorghum bicolor differing in visible reflectance due to cuticular waxes. Using the sorghum sheath reflectance and cuticle surface characteristics as a model, it was concluded that tree leaf reflectance above 0...

The morphogenesis of the composite epicuticular wax coverage and regeneration ability of the upper wax layer in Nepenthes alata pitchers were studied using a cryo-scanning electron microscopy. Examination of pitchers of different ages revealed six stages in the wax coverage development. In the first stage, wax crystals resemble those found recently in mature pitches of N. dicksoniana and N. ven...

U ltrastructure of the epicuticular wax of four commercially grown Canadian cultivars of canola (Brassica campestris cvs. Tobin and Candle, B. napus cvs. Altex and W estar) was investigated. Freeze-drying and air-drying methods of specimen preparation for scanning electron microscopy were compared. The freeze-drying method resulted in disruption and possible washing away of wax crystals, wherea...