Effectiveness of garlic lectin on red spider mite of tea

Abstract

Red spider mite (Oligonychus coffeae) is one of the major pests of tea and damages 5-15% of the total crop every year. Mannose binding 25 kDa lectins (ASAI, Allium sativum bulb agglutinin I and ASAII, A. sativum bulb agglutinin II), purified from bulbs of A. sativum (Garlic), was analyzed through SDS-PAGE and studied for its agglutination property using rabbit erythrocytes. Cross reactivity of the purified lectin was verified through western blot using anti-ASA antibody. ASAI was found to be a dimer built up of two heteromeric subunits whereas the ASAII is a homodimer. The insecticidal activity of the mixture of ASA lectins was tested against red spider mite in an artificial diet. The LC(50) values for red spider mite was determined to be 12.4 +/- 1.918 mu g/ml. This finding opens up a possibility of using the ASA genes against red spider mite through tea transgenic approach.