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University of Agricultural Sciences, Dharwad

The University of Agricultural Sciences, Dharwad was established on October 1, 1986. The University has 5 Colleges, 27 Research Stations, 6 Agriculture Extension Education Centers, 6 Krishi Vigyan Kendras and ATIC. The University has its jurisdiction over 7 districts namely Bagalkot, Belgaum, Bijapur, Dharwad, Gadag, Haveri, and Uttar Kannada in northern Karnataka. Greater diversity exists in soil types, climate, topography cropping and farming situations. The jurisdiction includes dry-farming to heavy rainfall and irrigated area. Important crops of the region include sorghum, cotton, rice, pulses, chilli, sugarcane, groundnut, sunflower, wheat, safflower etc. The region is also known for many horticultural crops. Considerable progress has been registered in the field of education, research and extension from this University.

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20151
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Subject: Plant Biochemistry × Author: ANUSHA KARKERA ×
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    ThesisItemOpen Access
    BIOCHEMICAL INVESTIGATIONS ON BIOTIC STRESS RESPONSE OF MANGO TO LEAFHOPPER INFESTATION
    (University of Agricultural Sciences Dharwad, 2015-06) ANUSHA KARKERA; Dr. KIRAN K. MIRAJKAR
    Increased production of reactive oxygen species (ROS) is associated with infestation caused by number of biotic factors in plants. The current work aims to study the defense mechanism of locally grown mango (Mangifera indica L.) varieties (Neelum, Pairi, Alphanso, Mulgoa and Totapuri) and hybrids (Ratna, Swarna Jahangir, Neelgoa, Neelesha and Mallika) against mango leafhopper infestation. Leafhopper infested and healthy leaves were collected at two stages of leaf maturity (new flush and old leaves) and the activity of the defensive enzymes such as Superoxide dismutase (SOD), Catalase (CAT), Peroxidase (POX), Glutathione reductase (GR), Polyphenol oxidase (PPO) and Ascorbate oxidase (AO), nitrogen assimilatory enzymes such as Nitrate and Nitrite reductase and the amounts of total phenol, reducing sugar and leaf chlorophyll content were analyzed. Insect infestation increased the antioxidant enzyme activities and total phenols in all the genotypes except Neelum, Pairi, Alphanso and Ratna at both stages. Alphanso and Ratna showed increased Peroxidase activity after insect feeding. Nitrogen assimilatory enzymes showed increase activity under infestation in all genotypes except in Neelum, Pairi and Alphanso. A decrease in reducing sugar and leaf chlorophyll was observed in the infested leaves compared with the healthy ones of new flush and old leaves. New flush possessed higher enzyme activities, total phenols and reducing sugar as compared with young leaves whereas, higher chlorophyll content was observed in old leaves. The improved performance of hybrids under leafhopper infestation was associated with more efficient antioxidant system response, particularly under conditions of stress.