Responses Of Leaf Elongation, Turgor, Osmotic Adjustment And Aba In 3 Durum Wheat (triticumdurum L.) Varietiesunder Waterstress Imposed By Peg

ln order to study the changes in water status, osmotic adjustment and turgor during a water stress period in wheat plants ; 3 varieties of dururn wheat Triticum durum were subjected to water stress of 5 bars using PEG6000 in hydroponics solution for one week. The growth of leaf 3 was monitored in relation to water status (RWC, osmotic potential and turgor pressu- re) in addition to the level of acid abscisic (ABA). Results showed that stressed plants main- tained turgor due to osmotic adjustrnent despite the decrease in growth rates. Results sug- gest that turgor is not the only factor regulating growth during the stress period and other factors such as cell wall extensibility are involved. Measurements of ABA concentration showed an increase in the elongation zone in Inrat 69 and MBB with maintenance of RWC in both varieties, suggesting a role of ABA in the increase of hydraulic conductivity in the cells of Elongation zone indicating a positive role of ABA in leaf elongation during water stress.