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331.
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 at811 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 7075d 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 相似文献
332.
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. 相似文献
333.
E. C. GONALVES A. SILVA M. S. R. BARBOSA M. P. C. SCHNEIDER 《Molecular ecology resources》2004,4(3):406-408
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. 相似文献