Tag Archives: carbohydrates

433-438 A. M. Méndez, D. Castillo , A. del Pozo, I. Matus, R. Morcuende
Differences in Stem Soluble Carbohydrate Contents among Recombinant Chromosome Substitution Lines (RCSLs) of Barley under Drought in a Mediterranean–type Environment
Abstract |
Full text PDF (140 KB)

Differences in Stem Soluble Carbohydrate Contents among Recombinant Chromosome Substitution Lines (RCSLs) of Barley under Drought in a Mediterranean–type Environment

A. M. Méndez¹, D. Castillo² ³, A. del Pozo², I. Matus³, R. Morcuende¹

¹Institute of Natural Resources and Agrobiology of Salamanca, IRNASA–CSIC, Apartado 257, 37071 Salamanca, Spain; e–mail: rosa.morcuende@irnasa.csic.es
²Faculty of Agricultural Sciences, University of Talca, Casilla 747, Talca, Chile
³Instituto de Investigaciones Agropecuarias CRI-Quilamapu, Casilla 426, Chillán, Chile

Abstract:

Drought is one of the major abiotic stresses that dramatically threaten the global food supply and it is becoming an increasingly severe problem in many regions of the world, mainly in Mediterranean areas and/or climates. This study investigates the effect of drought on the stem soluble carbohydrate content and its role in grain filling in different barley genotypes –four recombinant chromosome substitution lines (RCSLs) and the recurrent parent cv. Harrington, which had been growing in two contrasting Mediterranean environments in central Chile. At anthesis, drought stress increased the stem glucose and fructose contents in lines 76 and 78 and fructans in all the genotypes. At maturity, in non-stressed plants the soluble carbohydrate content in the stem decreased, suggesting a mobilization of carbohydrates from the stem into the grain. Drought increased the stem content of fructose, sucrose and fructans in all genotypes. The accumulation of fructans was higher in RCSLs as compared to Harrington, providing evidence that the introgression of the wild ancestor (Hordeum vulgare ssp. spontaneum) into cv. Harrington increases the terminal drought tolerance of barley. Line 89 showed the maximal content of fructans and it could be considered as the most tolerant to terminal drought of all RCSLs. However, this genotype showed the lowest grain weight and yield, indicating that is the most susceptible line of those referred to as grain yield.

Key words:

, , , , ,



443-450 R. Morcuende, P. Pérez, R. Martínez-Carrasco and E. Gutiérrez
Nitrogen Modulates the Diurnal Regulation of Nitrate Reductase in Wheat Plants – Projections Towards Climate Change
Abstract |
Full text PDF (88 KB)

Nitrogen Modulates the Diurnal Regulation of Nitrate Reductase in Wheat Plants – Projections Towards Climate Change

R. Morcuende, P. Pérez, R. Martínez-Carrasco and E. Gutiérrez

Institute of Natural Resources and Agrobiology of Salamanca, IRNASA–CSIC, Apartado 257, 37071 Salamanca, Spain; e–mail: rosa.morcuende@irnasa.csic.es

Abstract:

This study investigates whether the diurnal regulation of nitrate reductase activity in the flag leaf of wheat is affected by combined increases of CO2 and temperature in the air and to ascertain whether the nitrogen supply modifies these effects. Spring wheat was grown at ambient (360 μmol mol−1) or elevated (700 μmol mol−1) CO2, under ambient and 4°C warmer temperatures, and with two levels of nitrogen supply in field temperature gradient chambers. At ear emergence, NR activity reaches a maximum in the early part of the light period and declines later in the light period and during the first part of the night. Although elevated CO2 did not increase NR activity, it led to a modification of the diurnal regulation. During the last part of the photoperiod the decline of the activity was faster in plants grown in ambient CO2, in which the accumulation of amino acids was higher. The maximum reached in the first hours of the light period in plants grown in elevated CO2 and nitrogen abundance was related to a higher accumulation of soluble carbohydrates. The dark inactivation of NR was prevented in plants grown in elevated CO2 with low nitrogen. Additionally, the higher decline of NR activation in plants grown with ample nitrogen supply and higher temperatures was related to the accumulation of amino acids. It is concluded that nitrogen plays a role in the activity and post-translational regulation of NR under the future climatic scenario.

Key words:

, , , , , ,



662-667 D. Matt, E. Veromann and A. Luik
Effect of housing systems on biochemical composition of chicken eggs
Abstract |
Full text PDF (156 KB)

Effect of housing systems on biochemical composition of chicken eggs

D. Matt, E. Veromann and A. Luik

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi 1, EE51014 Tartu, Estonia; tel: +372 7425 010; e-mail: darja.matt@emu.ee

Abstract:

The aim of this study was to investigate the impact of production system (organic, conventional) on the quality of chicken eggs. Energetic value, carbohydrate, cholesterol, protein, fatty acid, sodium, potassium, phosphorus, dry matter and vitamin contents were evaluated. The mean content of cholesterol was 30%, and potassium 7%, greater in the organic eggs compared with the conventional eggs. No significant difference was found in the content of fatty acids, protein, sodium or dry matter. The organic eggs had considerably lower contents of calcium (2.8 times) compared with eggs from conventional farming. Negligible differences were found in the occurrence of vitamins (vitamin A, vitamin E, vitamin D3). The residues of 45 pesticides and 6 PCB isomers were analyzed in both types of eggs and no residues compounds were found.

Key words:

, , , , , , , , , , , , , , , ,



555-561 T. Tranavičienė, A. Urbonavičiūtė, G.Samuolienė, P. Duchovskis,I. Vagusevičienė and A. Sliesaravičius
The effect of differential nitrogen fertilization on photosynthetic pigment and carbohydrate contents in the two winter wheat varieties
Abstract |
Full text PDF (113 KB)

The effect of differential nitrogen fertilization on photosynthetic pigment and carbohydrate contents in the two winter wheat varieties

T. Tranavičienė¹, A. Urbonavičiūtė²⋅³, G.Samuolienė²⋅³, P. Duchovskis¹⋅²,I. Vagusevičienė¹ and A. Sliesaravičius¹

¹ Lithuanian University of Agriculture, Department of Crop Science and Animal Husbandry,53067 Akademija, Kaunas distr., Lithuania; e-mail: kokybe@kauno-grudai.lt
² Lithuanian Institute of Horticulture, Kauno g. 30, 54333 Babtai, Kaunas distr., Lithuania
³ Lithuanian University of Agriculture, Department of Botany

Abstract:

The effect of nitrogen fertilizers on photosynthetic indices in two winter wheat (Triticum aestivum L.) varieties ‘Ada’ and ‘Seda’ was investigated in the experimental station of Lithuanian University of Agriculture during 2005–2006 and 2006–2007. The rates of fertilizers during wheat vegetation were as follows: N90, N120 and N150. In sowing time bothvarieties were fertilized with N30P80K120. In tillering stage plants were fed with calcium-ammonium nitrate N60 and N80. In stem elongation stage they were fertilized through leaves withcarbamide solution N30 and N40. Wheat photosynthetic pigment and carbohydrate contents weredetermined in flowering and seed growth stages. The results of analysis show that photosynthetic pigment and carbohydrate status are suitable indicators of the activity of the winter wheat photosynthetic system. Suitably selected nitrogen fertilization design may delay the natural senescence processes. However, the emergence of the indices of senescence is also dependent on environmental conditions. Nitrogen remobilization and photosynthetic activity during natural senescence is cultivar specific. The photosynthetic system of ‘Ada’ wheat variety is more sensitive to the evocative factors than ‘Seda’ wheat. The soluble sugars also participate in senescence launching: the lower hexoses/sucrose ratio corresponds to decline in photosynthetic pigment degradation. Earlier photosynthetic senescence corresponds to reduced wheat grain yields.

Key words:

, , , ,