Modern methods of plant analysis
01 Jan 1964-
About: The article was published on 1964-01-01 and is currently open access. It has received 1991 citations till now.
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TL;DR: In this paper, the assessment of a number of physiological and xenobiotic metal concentrations occurring throughout the enological production processes of two native wines from Irpinia, Aglianico and Fiano of Avellino is presented.
96 citations
TL;DR: The essential oil of aerial parts of Salvia lanigera Poir growing wild in Cyprus was obtained by hydrodistillation and was analysed by GC and GC-MS for its antioxidant and antimicrobial activities.
96 citations
TL;DR: At both light levels, net assimilation rate (NAR) was more important than leaf area ratio (LAR) in explaining the effects of P on growth as indicated by GRCs, and at less severe P limitation, LAR became more important and NAR less important.
Abstract: We studied the effects of phosphorus (P) and light on the physiological and morphological components of growth of young tomato plants ( Lycopersicon esculentum Mill. cv. Capita). The importance of dry-mass partitioning and starch accumulation in explaining the effects of P limitation on growth was examined more closely. Plants were grown at a wide range of exponential P supply rates (between 70 and 320 mg g − 1 d − 1 ) and one free-access treatment (1 m M ). Two light levels (70 and 300 µ mol m − 2 s − − − 1 ) were applied. Growth response coefficients (GRCs) were calculated to address the importance of different growth parameters in explaining relative growth rate (RGR). At both light levels, net assimilation rate (NAR) was more important than leaf area ratio (LAR) in explaining the effects of P on growth as indicated by GRCs. At less severe P limitation, LAR became more important and NAR less important. Dry-mass partitioning to both roots and leaves played a minor role in determining the effects of P limitation on growth as indicated by low GRCs. The increase in starch at mild P limitation showed that the assimilate supply was not limiting. At severe P limitation, the rate of photosynthesis was decreased, as suggested by the decrease in starch accumulation.
95 citations
TL;DR: Using exotic melon germplasm, the authors have introgressed acidity into sweet melon, creating a new melon flavor, sweet-sour.
Abstract: Melon (Cucumis melo L.) is highly polymorphic for fruit traits, providing seemingly endless possibilities for genetic improvement through introgression and recombination. By expanding our knowledge of genetic variation for various fruit-quality components and relationships among them, we have attempted to create novel combinations of desirable fruit characteristics. Our goal is to present a brief review of our activities and efforts to identify melon germplasm that is outstanding for one or more fruit-quality components, and we will discuss examples of new combinations and relationships. Fruit quality is determined primarily by taste and a major component of taste is content of sugar, particularly sucrose. Unlike most fruits eaten fresh, commercially available melons lack acidity. Using exotic melon germplasm, we have introgressed acidity into sweet melon, creating a new melon flavor, sweet-sour. Another component of fruit quality is nutritive value, particularly carotenoids and ascorbic acid (vitamin C)....
95 citations
01 Jan 2001
TL;DR: The fact that the tree’s skeleton partly consists of green tissue has been known for centuries by bark-peeling basket makers, bast producers and even lovers who cut hearts into tree bark.
Abstract: Leaves are expected to be green (although they are sometimes reddish in the so-called blood forms or yellowish in the so-called aurea forms). The colour-determining pigments, the chlorophylls, are the cause of the leaves’ global importance in photosynthetic carbon fixation. The fact that stems can also contain chlorophyll is not directly evident. The outer bark layers are mostly brown (oak) or grey (beech, aspen) or sometimes even white (birch). However, bark tissues of younger twigs of trees are regularly greenish. The green colour is not caused by a surface layer of algae colonizing the outer wet parts of rhytidomes. By carefully peeling off layers of the dead outer bark of twigs and branches, a green colour indicates the presence of chlorophyll-containing tissues. The fact that the tree’s skeleton partly consists of green tissue has been known for centuries by bark-peeling basket makers, bast producers and even lovers who cut hearts into tree bark.
95 citations
References
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01 Jan 1963
TL;DR: In this article, a physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln.
Abstract: Kann ein physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), so besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln. Hierzu gehoren die Bestimmung der Reaktions- und Substratspezifitat sowie die Ermittlung der Bedingungen, unter denen eine optimale Wirkung des Enzyms gegeben ist. Wesentlich zur Charakterisierung ist ferner die Untersuchung der Stabilitat des Enzyms und dabei insbesondere die Feststellung, ob es sich um ein Ferment handelt, das zur vollen Aktivitat dialysable Cofaktoren benotigt. Falls diese Frage bejaht wird, ist auch die Bestimmung der unerlaslichen Cofaktoren anzuschliesen. Uberdies bietet auch der Nachweis der Lokalisation des Enzyms in der Zelle (oder im Zellverband) eine entscheidende Moglichkeit zur Charakterisierung des Fermentes. Hinzu kommt schlieslich noch die Untersuchung der Wirkung einzelner Inhibitoren1 auf das Enzym, die zu weitgehender Klarung des Reaktionsmechanismus beitragen kann und eine Abgrenzung der Eigenschaften des untersuchten Fermentes gegenuber ahnlichen Enzymen erlaubt.
2 citations
01 Jan 1962
TL;DR: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins and rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
Abstract: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins. Generally speaking denaturation can be defined as a process or sequence of processes in which the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement (Kauzmann 1959). The terms “configuration”, “conformation” and “state of folding” are widely used for spatial arrangement. It is probably best to follow the suggestion of Blout (1960) and restrict the use of “configuration” to its original sense, i.e. the spatial arrangement around an asymmetric carbon atom, and to use “conformation” for the shape of the molecule in its entirety. The properties discussed in the previous Chapter i.e., viscosity, diffusion, sedimentation, and light scattering — can all furnish information on the overall shape of proteins or other macromolecules and changes in this shape with environment. Thus Doty, Bradbury and Holtzer (1956) were able to show using these methods, together with streaming birefringence, that poly-γ-benzyl-L-glutamate could exist in two conformations, the α-helix and the solvated randomly coiled form, depending on the solvent. The change from α-helix to random coil was accompanied by marked changes in the optical rotatory properties of the polypeptides. It is to be expected that an α-helical structure should contribute to the rotatory power of a polypeptide since helices are asymmetric and not superimposable on their mirror images. The work on polypeptides has shown that rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
1 citations