Abstract

In the unirrigated regions, shortage of rain is one of the major problems in the development of agriculture. This climatic condition prevents plants to have a normal development and makes it harder for farmers to improve productions. Our research is focused in searching for genes associated with this abiotic stress in order to transfer them to important agriculture crops of arid zones. Our model plant is Algarrobo (Prosopis chilensis (Mol.) Stuntz), a tree adapted to this arid conditions. Previous to gene selection, relevant physiological aspects of the tree must be known in order to determine the best accession. In this work, we show seed germination performance of four (4) accessions of Algarrobo‟s under drought stress conditions. Two accessions represent the most northern distribution and the others two represent the most southern distribution. To generate drought stress, we supplied MS media with several concentrations of PolyEthylene Glycol (PEG) and Mannitol. For PEG, petri dishes contained 0,006M; 0,009M; 0,012M; 0,015M or 0,018M. For Mannitol, concentrations tested were 0,1M; 0,2M; 0,3M and 0,4M. Germination rates and roots elongation were measured daily. Preliminary results show that during first three weeks for both PEG and Mannitol, no significant differences on seed germination rates among accessions were observed. However, after the third week, drought stress generated by higher PEG and Mannitol concentrations provoked a slowing-down in root elongation and root thickness compared with controls, for almost all accessions. Further methodological approaches, results and conclusions obtained in this genetic background under drought stress conditions are discussed.