RESPONSE of FOUR BREAD WHEAT CALTIVARS (Triticum aestivum) UNDER ABIOTIC STRESS. II- IN SOME OF ANTIOXIDANT ENZYMES ,ORGANIC ACID AND ACTIVE IRON.

Abstract

ABSTREACT : To study effect of genotypes different experiments were conducted uses stats hydroponics technique, to intention study effect of Fe and three levels of bicarbonate stress (0,800,1600 µM/L) ,from KHCO3 silt . Four varieties of Bread Wheat (Iraq, Tahady, Fateh and Sally). Experiment setup using Complete Randomized Design (CRD). Results of this Study showed varieties exposure to Fe stress redound in development and emersion iron deficiency. Iron deficiency differences between wheat varieties .Varieties exposure to Fe,HCO3(800 and 1600 µM/L)stress exacerbate iron deficiency phenomenon . Active iron concentration a significant decreased when varieties grown under Fe, HCO3 stress, with superior Iraq in active iron concentration (11.00 and 28.20 mg/Kg) at highest HCO3 stress (1600 µM/L) under Fe deficient or efficient respectively. All varieties given high assemble of organic acid (Malic, Citric and Oxalic) in Roots. This is clear signaler on varieties were affected to Fe and HCO3 stress. Antioxidant enzymes activity (SOD,POD,CAT) were given clear signaler on effected of wheat varieties under Fe,HCO3 stress .This is deductive on scavenging to ROS eventual from Fe,HCO3 stress.Iraq given highest values in SOD(268.2 and 112.8 u/mg p.),when growth under Fe efficient or deficient respectively. Peroxidase enzyme was difference behavior as SOD .Iraq was given highest values of POD (28.23 and 46.33 Ua/gm) under Fe and HCO3 (1600 µM/L) stress .Highest values of CAT (46.36 to 153.44 u/mg p.) Was recorded with Iraq under Fe, HCO3 stress. This study suggested capability to use antioxidant enzymes activity as important criterion to separation efficiencies varieties which tolerance Fe, HCO3 stress, and give early signaler to varieties separation to stress tolerance.