Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : PHYSIOLOGICAL INDICATORS OF DROUGHT TOLERANCE OF WHEAT

Auteur : Guóth Forgóné Adrienn

Université de soutenance : University of Szeged Hongrie

Grade : Doctor of Philosophy PhD 2009

Présentation
Plant physiology is one of the most important areas of plant breeding. We investigated several uncleared questions which can facilitate the breeding process of wheat. Our aim was to find physiological parameters which correlate with drought resistance. These correlations can be useful for the breeders who could select the varieties according to the drought resistance related beneficial properties in young plants. Our aim was to compare the changes of the phisiological parameters in the young seedling stage under osmotic stress and in the in the garin filling period during water-defici and to find out whether the changes of these experiments correlate, and the changes obserbed in the seedling stage can charactherise the drought tolerance and final grain yield. We investigated whether the results of the experiment carried out in young seedlings can be used for charatherising the attitude of plants in the generative stage and for early determination of drought resistance or sensitivity of a wheat variety. _ The other main goal of our work was to charactherising the drought resistance and sensitivity and to determine which physiological parameter can unequivocally charactherise the agronomic traits of drought resistance, namely the yiled parameters. _ During our research work we were looking for the answers for the following questions : a) Are the changes of the phisiological parameters of the two sets of experiments comaparable ? Do the changes generated with PEG-6000 in the young seedlindgs correlate with those generated with soil dry in the grain filling period ? b) Is there any correlations between the photosynthetic activity of the flag leaves and the degree of grain filling ? c) How does the water-deficit effect the ABA (abscisic-acid) content of the flag leaves and grains and how do the changes of ABA concentartions influence the grain filling, final number and mass of grains ? d) How does the osmotic stress effect the ABA content of leaves and root in seedling stage ? Is there any correlation between these ABA contents and the root and shoot growth, biomass production and stomatal conductance ? e) How does the osmotic stress effect the root growth of the drought tolerant and sensitive varieties ? What are the role of NO (nitric oxide), ROS (reactive oxygen species) and ABA molecules in root growth under osmotic stress ? f) How does of the activity of abscisic aldehyde oxidase chnage in root under osmotic stress ?

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