CORRELATIONS AND DEGREE OF VARIATION BETWEEN YIELD AND SOME INDICATORS OF GROWTH AND CHEMICAL COMPOSITION OF THE GRASS FR THE BIRDSFOOT TREFOIL AND ITS MIXTURES WITH MEADOW GRASS SPECIES

 Boriana CHOURKOVA 

Abstract. From 2002 to 2005, the behaviour of local population of birdsfoot trefoil in binary mixtures with meadow grass species was conducted in the experimental field of RIMSA–Troyan. The variants of the experiment include testing of birdsfoot trefoil–variety Turgovishte 1 (referenceSt), cultivated its own and local population of birdsfoot trefoil in binary mixtures with tall fescue (Albena); perennial ryegrass (Pleven population); bromegrass (Nika); smooth–stalked meadow grass (Troyan population); orchard grass (Dabrava); red fescue (Troyan population); wheatgrass (Ruff). The height of plants shall be amended under the influence of weather conditions, the rate of growth and development of grasses interrelation and competitiveness of the components in grass composition indicative of received Variation coefficients.The production of birdsfoot trefoil and grass types varied with regard to treatments and years. The variation coefficients indicating yields stabilityshowed that it was best expressed in the mixture of birdsfoot trefoil and tall fescue (CV=45.42%) andorchagrdgrass(CV=48.65%).The values of crude protein in all variants were negative correlation coefficient. The correlationcoefficient of the compound with crude fiber content was very positive and strong correlations.

 Key words: birdsfoot trefoil, mixtures, productivity, chemical composition, correlation analysis, height

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COLLAGEN USE IN BIOCOMPATIBILITY ENHANCE OF POLYETHYLENE GLYCOL

Elena UTOIU, Maria Lungu, Viorica COROIU, Anca oANCEA

Abstract: New polymeric materials were prepared by mixing a biodegradable, water soluble synthetic polymer (polyethylene glycol–PEG) with a natural polymer with high degree of biocompatibility (type I collagen from bovine tendon). The blends were processed in the form of membranes by mixing aqueous solutions of components and drying of these mixtures. In vitro biocompatibility of polymer mixtures was evaluated by direct contact method, both qualitative methods (cytochemical staining cells with Giemsa) and quantitative methods (determination of cell viability in a culture of human dermal fibroblasts by MTT assay). Evaluation of these materials interaction with cell culture was also made by analyzing the activity of matrix metalloproteinases (MMP) by zymography. It was found that the mixture variant with the best degree of biocompatibility was PEG: Col 1:1 in combination ratio.

Keywords: synthetic polymers, natural polymers, mixtures, polyethylene glycol, collagen, NCTC cell line, biocompatibility, cell viability, matrix metalloproteinase.

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