ENZYMATIC AND BIOCHEMICAL STUDIES OF DEFENCE RESPONSES OF MANGO (Mangifera indica L.) HYBRIDS TO LEAFHOPPER INFESTATION

ANUSHA KARKERA¹, KIRAN KAMALAKAR MIRAJKAR²*, RENUKA SUDARSHAN PATIL^3
1Department of Biochemistry, University of Agricultural Sciences, Krishi Nagar, Dharwad, 580005, India
²Department of Biochemistry, University of Agricultural Sciences, Krishi Nagar, Dharwad, 580005, India
³Department of Biochemistry, University of Agricultural Sciences, Krishi Nagar, Dharwad, 580005, India
* Corresponding Author : mirajkarkk@uasd.in

Received : 18-11-2016     Accepted : 02-12-2016     Published : 06-12-2016
Volume : 8     Issue : 59       Pages : 3318 - 3325
Int J Agr Sci 8.59 (2016):3318-3325

Keywords : Antioxidant enzymes, Mango, Hybrids, Leaf hopper, Phenols, Defense response
Academic Editor : Shrvan Kumar
Conflict of Interest : None declared
Acknowledgements/Funding : We thank Directorate of Research, University of Agricultural sciences (UAS), Dharwad, Karnataka, India for financial support and Dr. Ashalatha Bhat (Dept. of Agril. Statistics) for the assistance in statistical analysis
Author Contribution : None declared

In the present study we evaluated the potential role of antioxidant enzymes and phenols in the defence response of five mango hybrids (Mangifera indica L.‘Mallika’, ‘Swarna Jehangir’, ‘Neeleshan’,‘Neelgoa’ and ‘Ratna’)to leafhopper infestation at two stages of leaf maturity (new flush and old leaves). Changes in activities of antioxidant enzymes namely superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), glutathione reductase (GR), polyphenol oxidase (PPO) and ascorbate oxidase (AO) and different biochemical parameters in infested leaves were observed as compared to healthy ones. Strong induction of peroxidase, glutathione reductase and polyphenoloxidase in new flush (88.14%, 89.53% and 78.99%) and old leaves 69.57%, 68.75% and 72.85%) was observed. The accumulation of phenols was preferentially enhanced (new flush-73.99% and old leaves-72.19%). Under infestation total chlorophyll and reducing sugar content were decreased in all the cultivars but to a varying degree. The antioxidant activities of mango leaves was significantly affected by leaf age with higher constitutive and induced levels in new flush as compared to old leaves. Mallika with the highest basal and induced antioxidant enzyme activities is indicated as the most tolerant hybrid whereas Ratna having the lowest is reported as the most sensitive hybrid to leafhopper infestation. Our results implicated that peroxidase, polyphenol oxidase, glutathione reductase and phenols played an important role in integrated defence response of mango to leafhopper infestation and the hybrids with higher levels of tolerance exhibited higher capacity for up regulation of defensive enzymes.