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Desiccation effects on rate and pattern of protein synthesis in Brassica napus (cv westar) and Brassica juncea (cv cutlass) have been examined. Results showed that while the rate of water loss was similar in the two species, the inhibition of amino acid incorporation was greater in B. napus than B. juncea at any given level of desiccation. Electrolyte leakage increased with the degree of desiccation and was greater in B. napus than in B. juncea. In both, the increase in leakage was much sharper after 12 hours of desiccation. Quantitative changes in patterns of boiling-stable protein synthesis due to desiccation stress were observed. The control level of protein radioactivity which was boiling-stable in B. napus was 16.16% and 19.96% for B. juncea. After desiccation, the percentage of boiling-stable radioactivity increased to 23.30% for B. juncea and 16.63% for B. napus. In vitro translation of total RNA indicated that desiccation alone does not induce the synthesis of new mRNA species in either cultivar, but it may change the translation pattern resulting in different levels of abundance of proteins.

The thesis describes characteristics of rapeseed and its life cycle. Its main objective is to approach the problematics of weeds in the spring formo of rapeseed on the lands of agricultural company AGRO Dolní Bukovsko. Small-plot experiment was founded on cadastral area Bzí near Dolní Bukovsko, in direction to Týn nad Vltavou. The problems in cultivation of cultural plants are caused by weeds, which are negatively affecting the quality of production as well as the economics of cultivation. Evaluation of weeds was carried out by the counting method in the period since March to August 2016. Number of the weed plants which were found on the particular location was regularly registered and evaluated. In the conclustion it is possible to state that long-term regulation of weed occurence has to be undertaken in time, thoroughly and has to be based on complete protection. Complete protection consists of direct and indirect methods of regulation. As one of the many but most effective possibilities it is possible to use herbicide preparations

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Thesis (M.S.) in Resource Economics and Policy--University of Maine, 2001. / Includes vita. Advisory Committee: James D. Leiby, Assoc. Prof. of Resource Economics and Policy, Advisor; Mario F. Teisl, Asst. Prof. of Resource Economics and Policy; Kathleen P. Bell, Asst. Prof. of Resource Economics and Policy. Includes bibliographical references (leaves : 52-53).

Phosphatidate phosphatase (PAP. EC 3.1.3.4) was charaterized from developing seeds and microspore-derived (MD) cultures of oilseed rape. In studies with homogenate from developing seeds (Brassica napus L. cv Westar) the time course for release of inorganic phosphate from phosphatidate was linear for at least 60 min and the enzyme was stable to at least three cycles of freezing and thawing. Differential centrifugation studies were conducted with homogenate prepared from developing seeds (B. napus L. cv Westar), MD embryos (B. napus L. cv Reston), and an embryogenic MD cell suspension culture (B. napus L. cv Jet Neuf). Among the three tissue types, the level of microsomal PAP ranged from 11% to 17% of the total recovered PAP activity whereas soluble PAP ranged from 25% to 61% of the total activity recovered. Microsomal PAP displayed optimal activity in the pH range of 6 to 7 whereas soluble PAP had a pH optimum of 5. Microsomal and soluble PAP exhibited temperature reaction optima of 40 degrees celsius and 50 degrees celsius, respectively, with activation energies of 15.6 kcal/mol and 9.4 kcal/mol. Assays with p-nitrophenyl phosphate as a substrate at pH 6.75 and pH 5 indicated that the overal character of phosphatase activity in the microsomal fraction was different from the enzyme in the soluble microsomal PAP from MD embryos of B. napus L. cv Topas. Tween 20 solubilized PAP effectively with concomitant maintenance of enzyme in the soluble fraction. A number of detergents were screened for their ability to solubilize microsomal PAP from MD embryos of B. napus L. cv Topas. Tween 20 solubilized PAP effectively with concomitant maintenance of enzyme activity. The most effective solubilization of enzyme occurred at a concentration of 0.4% (w/v) Tween 20 at a detergent to protein ratio of 1:1 (w/w). The pH optimum (pH 6-7) of solubilized PAP was similar to that of the particulate enzyme and the assay of the solubilized enzyme was free from interference by phospholipase action. Solubilized microsomal PAP had an apparent Mr of about 300,000 based on gel filtration chromatography on a column of Superose 6. Polyclonal antibodies raised in mice against a crude extract from microsomes of MD embryos inhibited microsomal PAP activity. / xii, 128 leaves : ill. ; 29 cm.

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Studies have shown that including perennial forages in cropping rotations can increase soil carbon (C) and lower nitrous oxide (N2O) emissions when compared to continuous annual cropping. Research is needed to evaluate the inclusion of a perennial forage in an annual crop rotation on net carbon dioxide (CO2) and N2O fluxes, natural and agronomic drivers of seasonal greenhouse gases (GHGs), and the possibility of using forages as a C sequestration-CO2 mitigation tool. A long-term field experiment site to determine GHG budgets for Red River Valley cropping systems in Manitoba, Canada was used. The site consisted of four plots with the same annual rotation management history. A perennial legume, alfalfa, was grown in 2008 and 2009 on two plots and spring wheat and industrial oilseed-rapeseed grown on the other two plots in 2008 and 2009, respectively. Nitrous oxide and CO2 fluxes were measured continuously using the flux gradient micrometeorological method. For the net study period, the perennial phase sequestered twice the atmospheric CO2 (2070 kg C ha-1) compared to the annual crops. The annual rotation emitted 3.5 times more N2O than the perennial legume phase. When accounting for harvest C removals and considering GHGs in CO2-equivalent (eq.), the perennial legume phase was a net sink of 5440 kg CO2-eq. ha-1 and the annual rotation was a net source of 4500 kg CO2-eq. ha-1 for the two year study period. Information gathered will help bridge missing data gaps in national emission trends and enhance development of Canadian GHG mitigation models.