Tag Archives: stem

277-286 A. Bārdulis, D. Lazdiņa, M. Daugaviete, A. Bārdule, U. Daugavietis andG. Rozītis
Above ground and below ground biomass in grey alder Alnus incana (L.) Moench. young stands on agricultural land in central part of Latvia
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Above ground and below ground biomass in grey alder Alnus incana (L.) Moench. young stands on agricultural land in central part of Latvia

A. Bārdulis*, D. Lazdiņa, M. Daugaviete, A. Bārdule, U. Daugavietis andG. Rozītis

Latvian State Forest Research Institute ‘Silava’, Rigas street 111, LV2169 Salaspils, Latvia; *Correspondence: andis.bardulis@silava.lv

Abstract:

Young grey alder stands under 10 years of age that are growing on abandoned agricultural lands in Central Latvian lowlands were selected for this study. In the framework of the research the biomass of the trees was studied and an equation was developed for grey alder stands on abandoned agricultural lands. An allometric equation for the different biomass fractions of grey alder was developed. Tree biomass is characterised by a power model with a single independent variable (DBH), which also indirectly substitutes for the effect of the stand age. The model is adapted to each fraction by changing its ratio values. The determination coefficient of the model is high, varying from R2 = 0.89 to R2 = 0.94, and the confidence level of the model is 95%. The biomass of particular fractions is defined by a power regression, with the tree stem diameter at the height of 1.3 m used as an argument. In young grey alder stands on abandoned agricultural lands the majority, 64%, of root fractions is composed of coarse roots, followed by the stump fraction and fine roots, 28% and 8%, respectively. For aboveground biomass the largest fraction is stem, which constitutes 75% of the total aboveground biomass, while the share of branches is 25%.

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1202-1214 M. Golabadi, P. Golkar and B. Bahari
Remobilization assay of dry matter from different shoot organs under drought stress in wheat (Triticum aestivum L.)
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Remobilization assay of dry matter from different shoot organs under drought stress in wheat (Triticum aestivum L.)

M. Golabadi¹*, P. Golkar² and B. Bahari¹

¹Department of Agronomy and Plant Breeding, Collage of Agriculture, Isfahan (Khorasgan) Branch, Islamic Azad University, P.O. Box: 81595-158 Isfahan, Iran
²Institute of Biotechnology and Bioengineering, Isfahan University of Technology, P.O. Box: 84156-2781 Isfahan, Iran
*Correspondence: m.golabadi@khuisf.ac.ir

Abstract:

Remobilization of dry matter during the grain filling period in wheat is capable of helping the plant recover its grain yield under drought stress. In this study, the genotypic variation of different traits related to dry matter remobilization were measured in seven genotypes of wheat under the three different environment conditions of well-watered, drought stress at heading stage with application of extra nitrogen fertilizer (30%), and drought stress in Isfahan, Iran. Analysis of variance showed that the genotypes were different not only in their dry matter remobilization from the spike, the stem, the peduncle, and the leaf sheath but also in their current photosynthesis. Different environmental conditions were found to affect dry matter remobilization from the leaves and sheath, current photosynthesis, grain yield, and the relative contributions by the stem and the spike to grain yield. The highest values of spike and stem contribution to grain yield were obtained under drought stress while current photosynthesis was found to be the sole supplier for grain filling in normal conditions. Application of extra nitrogen fertilizer under drought stress was found to reduce the loss of grain yield in some genotypes as a result of enhanced vegetative growth, reserve accumulation, and dry matter remobilization to the grain.

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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
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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.

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