Vessel origins in Nymphaeaceae: Euryale and Victoria

Metaxylem tracheary elements of roots have differentiation between end walls and lateral walls in both Euryale and Victoria End walls have narrower, more closely spaced bars and scalariform plates. primary walls of end walls (and, to a lesser extent, lateral walls) have striations that are thickened primary wall portions orientated in an axial direction. These striations are less common in Victoria than in Euryale. Although secondary wall strands between perforations occur in some dicotyledons, the report of primary wall striations is new; these can be seen with scanning electron microscopy (SEM) but not with light microscopy. Perforations occur irregularly and sometimes sparsely on end walls of tracheary elements of Victoria , but perforations were not observed in Euryale. Thus, Euryale satisfies one criterion for the presence of vessel (end wall different from lateral wall), whereas Barclaya satisfies another (perforations in end walls) and Victoria satisfies both. Vessel origins in Nymphaeaceae are important in illustrating that there may be multiple vessel origins in dicotyledons.     

Solute Accumulation by Grape Pericarp Cells: V. RELATIONSHIP TO BERRY SIZE AND THE EFFECTS OF DEFOLIATION

We have studied the accumulation of water, dry matter (DM) andglucose and fructose (G + F) in selected grape berries cv. Dolcettoof varying initial size growing on leafed and defoliated vines.The first measurements at 2 d after veraison were obtained non-destructivelyfrom correlations with linear dimensions and deformability;the final measurements were made when the berries were harvested13 d later. The increments in DM and G + F per pericarp increased with initialberry size thus discounting an hypothesis of an equal amountof solutes supplied to all berries. The increments in weightof DM and G + F per increment of pericarp volume were constantin berries of different size, supporting an hypothesis of acontrol determined by concentration in the solution availablefor accumulation in all berries. Defoliation reduced the incrementsper pericarp and per g fr. wt. by about the same proportionand its effects were consistent with the above interpretations. Key words: Grape pericarp, sugar accumulation, phloem unloading, Vitis vinifera.     

Phases of Berry Growth in Vitis vinifera

The course of berry growth in Vitis vinifera has been interpreteddifferently by various authors. Divisions into two, three orfour phases have been postulated, though, in the latter cases,without any objective criteria for their delimitation. To clarifythis point, investigations were carried out with the cultivarsBacchus and Madeleine. Fresh and dry wt curves showed a double sigmoid course and threetransition points could be clearly defined. The central transitionpoint, occurring around 42 d after anthesis, may be definedas the change-over from the first to the second growth phase.Both the course of the fresh weight curve when plotted logarithmicallyand the relative growth rates argue against there being a phaseof slow growth at the beginning of the first growth phase. Indeed,the relative increase in fresh weight is maximal at the beginningof the first growth phase. The delimitation of a separate phase of little or no growthin the region of the transition from the first to the secondgrowth phase is not supported. The definitions of such phaseboundaries is arbitrary. The smaller the number of seeds perberry, the earlier is the first growth phase ended and the secondgrowth phase, including veraison, begun. During the first growth phase there is high cell division activity.The average area of an epidermal cell reached its minimum at8–11 d after anthesis, with a simultaneous strong increasein cell number. The maximal number of epidermal cells was attainedtowards the end of the first growth phase. The growth of the embryo showed no relation to the double-sigmoidalgrowth of the pericarp. Final embryo size was reached at 70–75d after anthesis. Seed d. wt, on the other hand, showed a biphasicincrease. The results presented here support the division of berry growthof V. vinifera into just two phases. Vitis vinifera L., grape vine, berry growth, growth phases     

Multiplication cellulaire et production lipidique en culture in vitro chez Taphrina insititiae et Taphrina pruni, parasites de Prunus domestica

Cellular Multiplication and Lipid Synthesis during in vitro Culture of Taphrina insititiae and Taphrina pruni, Parasites of Prunus domestica. Two Taphrina species were grown on “yeast extract/glucose” and harvested at regular intervals. Their growth was estimated by dry mycelial weight and cell nitrogen. Lipids were recovered and measured by weighing. Phospholipids, which form the major portion of polar lipids, were measured by phosphorus assay. Lipidic and nitrogenous products were studied with regard to the evolution of the cultures during the phase of active growth. The cells accumulated fats, but during the phase of autolysis, fat content decreased. Production of nitrogenous components was maximal during the autolytic phase. Phospholipids varied as nitrogenous and inversely to neutral lipids. There was apparently an antagonism between nitrogen assimilation and synthesis of neutral lipids. Different functions of neutral and polar lipids may be involved, so that the former act as a reserve material and the latter represent an essential structural cell constituent. Fatty acids were analysed by gas liquid chromatography at various culture periods. Fatty acids from polar as well as those from neutral lipids exhibited great variations with regard to culture evolution. The ratio insaturated/saturated fatty acids is greater in polar lipids than in neutral lipids. These variations are discussed with regard to their consequences for the function of cell membranes.     

Isolation and characterization of microsatellite loci in Amazonian red‐handed howlers Alouatta belzebul (Primates,Plathyrrini)

Ten highly polymorphic microsatellite loci are described for Amazonian red‐handed howlers (Alouatta belzebul), an endemic Brazilian primate species subject to intense hunting pressure. The number of alleles observed in 30 individuals ranged from nine to 20, and observed heterozygosity varied from 0.35 to 0.93. No linkage associations were evident from pairwise comparisons of loci. These microsatellites offer a powerful tool for fine‐scale studies of genetic structure in both captive colonies and wild populations of red‐handed howlers.     

Tarsal contact chemoreceptor response to glucosinolates and cardenolides mediating oviposition in Pieris rape

Abstract. Water-soluble extracts of a host crucifer (Brassica oleracea L.) and non-host crucifer (Erysimum cheiranthoides L.) and isolated pure cardenolides and glucosinolates were tested on Pieris rapae L. (Lepidoptera: Pieridae) butterflies in oviposition assays and by electrophysiological recordings from the contact-chemoreceptor sensilla of the prothoracic tarsi. Ten different glucosinolates stimulated oviposition to varying degree when put on non-host plant leaves. The most active compounds were glucobrassiein and gluconasturtiin (methylindole and phenylethyl aglycone), whereas glucocapparin, sinalbin. glucotropaeolin, sinigrin and glucoalyssinin had intermediate activity. Glucocheirolin, glucoerucin and glucoiberin (sulphur-containing aglycone) were significantly less active. Of eight cardenolides applied to host-plant leaves (100 μg each), four glycosides deterred oviposition strongly (erysimoside, erychroside, cymarin and K-strophanthin-β). Erycordin, helveticoside, digitoxin and strophanthidin had little or no deterrent activity. Sensilla located laterally on the prothoracic tarsi of female butterflies contained one receptor cell sensitive to sucrose. None of the tested extracts or pure compounds stimulated any cell in these sensilla. In contrast, the cells in the medial sensilla showed little or no sensitivity to sucrose. One cell was found to be sensitive to cardenolide glycosides. The threshold for one of the most active compounds, erychroside, was about 0.1 μg/ml (1.5 times 10^-7 M). Two receptor cells, characterized by spikes of differing amplitude, were sensitive to glucosinolates. One of these, with larger amplitude spikes, seemed to be the same as the cell sensitive to cardenolides. The threshold for the most active glucosinolates, glucobrassicin and gluconasturtiin was estimated to be below 0.1 mg/ml (2 times 10^-4 M). The neural activity of both classes of compounds, cardenolides and glucosinolates, was significantly correlated with their behavioural activity as deterrents or stimulants.