Improved selection against the purple colour defect of cauliflower curds     

P. Crisp  Patricia A. Jewell  A. R. Gray 《Euphytica》1975,24(1):177-180

Summary Purple colourations of the cauliflower curd detract from the commercial value of the crop. Curds were found to develop purple colourations when in aseptic nutrient culture, and this was correlated with their inherent tendencies to form purple curds in the field as revealed by a progeny test. It was advocated that selection against the defect in the field should be supported by assessment in culture.  相似文献   

Breeding system,taxonomy, and breeding strategy in cauliflower,Brassica oleracea var. botrytis L.)     

A. R. Gray  P. Crisp 《Euphytica》1977,26(2):369-375

Summary Cauliflowers representing those maturing in Britain in autumn, winter and spring were assessed for self-compatibility by self-pollen tube growth. A tendency existed for groups taking longer to mature to be more self-incompatible, but a range of incompatibilities was apparent in all groups. These results complement those of other workers.It is argued that despite demonstrable heterosis within many groups of cauliflowers, radical advances are probably best made by selecting self-compatible material from annual × biennial hybrid populations.  相似文献   

Soil Factors Affecting Heavy Metal Solubility in Some New Zealand Soils     

Colin W. Gray  Ronald G. Mclaren 《Water, air, and soil pollution》2006,175(1-4):3-14

Heavy metal contamination of soils is usually quantified and guidelines set solely on the basis of total heavy metal content. However, it is recognised that water soluble heavy metal concentrations may provide a better indication of the potential risk that heavy metals may pose to the soil environment. The aim of this study was to use a semi-empirical model based on the competitive adsorption of metal and H⁺ ions [dependent on solution pH, total metal content, total carbon content and soil oxide content] to predict water soluble Cu, Cr, Cd, Pb, Ni and Zn concentrations in a range of field contaminated soils. The results of multiple linear regressions showed that basic soil properties could predict 85, 72, 66, 78, 50 and 75% of the variation in soluble Ni, Cu, Cr, Pb, Cd and Zn concentrations respectively. Water soluble metal concentrations were best predicted using empirical linear regressions which included total metal content, while the importance of other soil properties such as soil pH, total carbon and oxalate extractable Fe and Al oxides varied between metals. The models have the potential to provide valuable information on metal availability in contaminated soils and offer an indication of the potential risk a metal may pose to a given soil environment, along with providing a basis for developing soil quality guidelines for the prevention, investigation and clean-up of soil metal contamination.  相似文献   

Infusion of volatile flavor compounds into low-density polyethylene     

Avison SJ  Gray DA  Davidson GM  Taylor AJ 《Journal of agricultural and food chemistry》2001,49(1):270-275

Supercritical fluids can extract components from some matrixes (e.g., fat and flavors from food) as well as infusing additives into synthetic polymer matrixes. To study the feasibility of infusing flavors into matrixes as a potential flavoring mechanism, a wide range of volatile flavor compounds was infused into a well-defined synthetic polymer (low-density polyethylene) using supercritical carbon dioxide. The polymer was then extracted, and the amount of infused compound was determined. The effects of time, temperature, pressure, rate of depressurization, volatile concentration, and volatile properties on the degree of infusion were studied. Infusion with supercritical carbon dioxide achieved much higher loadings of the polymer (0.01 to 6.87 mg/g LDPE, depending on the volatile molecule being infused) compared to those achieved by static diffusion. Forty-five volatiles were infused, from which a model was developed to predict infusion as a function of certain physicochemical properties.  相似文献   

Development of an immunological technique for estimating mycelial biomass of Mycena galopus in leaf litter     

Juliet C. Frankland  A.D. Bailey  T.R.G. Gray  A.A. Holland 《Soil biology & biochemistry》1981,13(2):87-92

Antisera were produced in rabbits against cell wall and cytoplasmic components of the mycelium of a litter-decomposing basidiomycete, Mycena galopus (Pers. ex Fr.) Kummer. The antisera were conjugated with fluorescein isothiocyanate, and positive reactions were obtained in direct and indirect fluorescent antibody (FA) tests with homologous antigens and with heterologous antigens of M. galopus from pure cultures and field material. Cross reactions occurred with fungal associates of M. galopus on Quercus litter from a deciduous woodland, but these were mostly removed by absorption with a preparation of Cladosporium herbarum Link ex Fr. Membrane filtration combined with FA staining and rhodamine-gelatin counter-staining was found to be a feasible means of estimating the biomass of FA-reactive mycelium of M. galopus in leaf litter.  相似文献   

Support of graduate education     

Gray PE 《Science (New York, N.Y.)》1982,216(4542):129

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Induction of tumors in mice by genomic hypomethylation   总被引：1，自引：0，他引：1  

Gaudet F  Hodgson JG  Eden A  Jackson-Grusby L  Dausman J  Gray JW  Leonhardt H  Jaenisch R 《Science (New York, N.Y.)》2003,300(5618):489-492

Genome-wide DNA hypomethylation occurs in many human cancers, but whether this epigenetic change is a cause or consequence of tumorigenesis has been unclear. To explore this phenomenon, we generated mice carrying a hypomorphic DNA methyltransferase 1 (Dnmt1) allele, which reduces Dnmt1 expression to 10% of wild-type levels and results in substantial genome-wide hypomethylation in all tissues. The mutant mice were runted at birth, and at 4 to 8 months of age they developed aggressive T cell lymphomas that displayed a high frequency of chromosome 15 trisomy. These results indicate that DNA hypomethylation plays a causal role in tumor formation, possibly by promoting chromosomal instability.  相似文献   

Self-incompatibility: a self-recognition system in plants   总被引：18，自引：0，他引：18  

V Haring  J E Gray  B A McClure  M A Anderson  A E Clarke 《Science (New York, N.Y.)》1990,250(4983):937-941

Self-incompatibility (SI), a genetically controlled mechanism to prevent inbreeding in plants, offers a relatively simple model system for studying the interactions between plant cells or between a plant cell and the secreted product or products of another cell. Examples of two major types of SI, gametophytic and sporophytic, have been studied by cloning cDNAs corresponding to glycoproteins of the female tissues that segregate with particular variants encoded by the putative S locus. These secreted glycoproteins are envisaged to interact with the currently undescribed pollen component to cause arrest of pollen tube growth.  相似文献   

Requirement for activin A and transforming growth factor--beta 1 pro-regions in homodimer assembly   总被引：10，自引：0，他引：10  

A M Gray  A J Mason 《Science (New York, N.Y.)》1990,247(4948):1328-1330

Many proteins are initially synthesized as part of a large precursor. The role of the pro-region in the biosynthesis of transforming growth factor--beta 1 (TGF-beta 1) and activin A, two structurally related disulfide-linked homodimers synthesized as large precursors, was studied. Vectors that expressed either the pro-region or the mature regions of these molecules were used in complementation experiments, only when the pro-region was coexpressed with the mature region did intracellular dimerization and secretion of biologically active homodimers occur. The pro-regions of activin A and TGF-beta 1, therefore, aid the folding, disulfide bond formation, and export of their respective homodimers.  相似文献   

Heme-heme orientation and electron transfer kinetic behavior of multisite oxidation-reduction enzymes   总被引：1，自引：0，他引：1  

M W Makinen  S A Schichman  S C Hill  H B Gray 《Science (New York, N.Y.)》1983,222(4626):929-931

Analysis of the polarized single-crystal absorption spectra of cytochrome cd1 of Pseudomonas aeruginosa shows that the heme c and heme d1 groups in each subunit are oriented perpendicularly to each other in both oxidized and reduced forms of the enzyme. These results, together with those of previous kinetic studies, indicate that a perpendicular heme-heme orientation may be an important factor in specifying kinetically slow steps in a sequential series of electron transfer reactions.  相似文献