Physiological and Biochemical responses of two high yielding Groundnuts Cultivars (Arachis hypogaea L.cv. KCG-6 and GPBD-4) of Karnataka with Contrasting Drought tolerance.

B.V.KRISHNAPPA[1], SUDHAKAR. C[2]
Page No 18-25

Water stress resulted in a significant modification in the level of anti oxidative metabolism. An
antioxidant is a molecule that inhibits the oxidation of other molecules. A pot culture experiment in
two different groundnut (Arachis hypogaea L.) cultivars (KCG-6 and GPBD-4) of groundnut
seedlings were studied using biochemical and histochemical methods to estimate accumulation
levels of antioxidant such as Ascorbic Acid Content, antioxidative enzymes such as ascarbate
peroxidase (APX) Superoxide dismutase (SOD) and Guaiacol Peroxidase (GPX) and ROS levels.
Plants were grown in pots under controlled environmental conditions, and subjected to water stress
regimes characterized as control, mild, moderate and severe stress represented by 100, 75, 50 and
25% soil moisture for 12 days. However, the percent increase of antioxidants as well as anti
oxidative enzymes was higher in cv KCG-6 and lower in cv. GPBD-4. The water stress resulted in
increase in free radicals (O2ˉ˙, Content, H2O2) in both cultivars, but more significantly in cultivar
GPBD-4 than KCG-6. Profile analysis of anionic isoenzymes and total enzymes activity assay of
superioxide dismutase (SOD), guaiacol peroxidase (GPX) and asorbate peroxidase (APX) revealed
qualitative changes occurred during water stress in both cultivars. The accumulation of ROS,
antioxidants and anti oxidative enzymes in relation to water stress of these cultivars was discussed.
.The present study indicated that cv. KCG-6 is water stress tolerant than cv. GPBD-4.
Key words: Groundnut (Arachis hypogaea L.), Water stress, Antioxidant enzymes, antioxidant
parameters, APX, SOD, ROS, GPX, O2ˉ˙, Content, H2O2