Ramasamy Asokan

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Bemisia tabaci is the major vector pest of agricultural crops all over the world. In this study we report the different bacterial endosymbionts associated with B. tabaci sampled from 14 different locations in North India. Using 16S rDNA clone library sequences we were able to identify Portiera, the primary endosymbiont of B. tabaci, and other secondary(More)
The cotton bollworm, Helicoverpa armigera is a highly polyphagous pest infesting a number of economically important crops, annually causing enormous crop losses. Management of this pest is challenging over the years due to various factors including development of resistance to wide spectrum of chemical insecticides. RNA interference (RNAi) has tremendous(More)
The Western Ghats of Karnataka natural ecosystem are among the most diverse and is one of the eight hottest hotspots of biological diversity in the world, that runs along the western part of India through four states including Karnataka. Bacillus thuringiensis (Bt) strains were isolated from soils of Western Ghats of Karnataka and characterized by molecular(More)
Dengue fever and dengue haemorrhagic fever (DF/DHF) have become a serious public health problem in many parts of India in recent years. Several vertical national programmes for communicable diseases, which include vector-borne diseases such as malaria and filariasis have been in operation for over five decades in India. The remarkable increase in dengue(More)
A quick and developmental-stage non-limiting method of the identification of vectors of tospoviruses, such as Thrips tabaci and T. palmi, is important in the study of vector transmission, insecticide resistance, biological control, etc. Morphological identification of these thrips vectors is often a stumbling block in the absence of a specialist and limited(More)
The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a phloem-feeding, economically important pest of crops worldwide. In addition to direct damage, it also vectors a number of plant viruses belonging to the family Geminiviridae. Its populations differ biologically with respect to insecticide resistance, virus transmission and host range.(More)
Bt strains were isolated from soils of Andaman and Nicobar Islands and characterized by microscopic and molecular methods. Diversity was observed both in protein and cry gene profiles, where majority of the isolates showed presence of 65 kDa protein band on SDS-PAGE while rest of them showed 130, 72, 44, and 29 kDa bands. PCR analysis revealed predominance(More)
The mediator of haemolysis in the plasma of the horseshoe crab, Limulus polyphemus, is limulin, a sialic acid-binding lectin. The haemolytic activity of limulin is inhibited by thiol ester-reacted forms of Limulus alpha(2)-macroglobulin, the third-most abundant protein of the plasma. Limulus alpha(2)-macroglobulin that has experienced cleavage of its(More)
Bacillus thuringiensis (Bt) strains were isolated from soil samples of Great Nicobar Islands, one of the “hottest biodiversity hotspots,” where no collection has been characterized previously. The 36 new Bt isolates were obtained from 153 samples analyzed by crystal protein production with light/phase-contrast microscopy, determination of cry gene profile(More)
Characterization, direct sequencing of the PCR amplicon and phylogenetic relationship was done to discover a novel Vip protein genes of the Bt isolates, to improve the prospects for insect control, more Vip proteins should be sought out and researched to predict their insecticidal activity. Characterization was based on direct sequencing of PCR amplicon(More)