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Accueil du site → Doctorat → Autriche → The effect of drought stress on morpho-physiological traits of alfalfa (Medicago sativa L.) genotypes under organic farming

Universität für Bodenkultur Wien (2010)

The effect of drought stress on morpho-physiological traits of alfalfa (Medicago sativa L.) genotypes under organic farming

Moghaddam, Ali

Titre :The effect of drought stress on morpho-physiological traits of alfalfa (Medicago sativa L.) genotypes under organic farming

Auteur : Moghaddam, Ali

Université de soutenance : Universität für Bodenkultur Wien

Grade : Doctoral 2010

Résumé
Legume fodder crops such as alfalfa (Medicago sativa L.) are an essential component of organic systems especially in arid and semiarid conditions. In this study, 8 Iranian ecotypes and 10 European cultivars were evaluated under irrigated and rain-fed conditions at the research station of BOKU University, Austria, during 2006-08. The objectives of study were : i) assessing of adaptability of different genotypes under irrigated and rain-fed organic farming ; ii) assessing of drought stress effects in rain-fed experiment on performance of genotypes and suitability of different drought tolerance indices for selection of superior genotypes ; iii) studying of correlation between different characters under both conditions ; v) measuring genetic distance and divergence between genotypes and classifying them based on morphological and physiological characters ; iv) evaluating carbon isotope discrimination [delta] of genotypes in different plant parts and association between water use efficiency (WUE) and [delta] in both conditions. Except for leaf to stem ratio, shoot and root protein content, average of all traits was reduced under stress condition in rain-fed trial. The cultivar Sitel was the best genotype (as wide adapted genotype) across two conditions. Plant height and LAI can be considered as primary selection criteria for improving shoot DM. Cluster analysis clearly differentiated Iranian and European genotypes from each other using morphological and physiological data. Stress tolerance index (STI) and geometric mean productivity (GMP) were the best indices to distinguish genotypes with high performance in both conditions. The relation between water use efficiency and [delta] responses of genotypes (shoot, stubble and root) were variable based on plant part and study conditions (irrigated and rain-fed)

Mots clés : Drought stress / Biological nitrogen fixation / Repeated measure analysis / [Alpha]-Lattice design / Stability analysis / Path analysis / Cluster analysis / Iranian ecotypes / Water use efficiency / Carbon isotope discrimination

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Page publiée le 4 septembre 2010, mise à jour le 13 mars 2019