Author:
Naik Mahadev,Kalmath Basavaraj,Lakshmikanth ,Rao Saroja,Dastager Syed,Hosamani Arunkumar,Avar Basavaraj Kadann,Naik Harischandra
Abstract
The present study evaluated fifteen Bacillus thuringiensis (Berliner) isolates against second instar larvae of tobacco leaf eating caterpiller Spodoptera litura (F) and Vip genes were identified in the effective isolates. Four NCIM isolates (5111, 5112, 5116 and 5117) were found promising, and their LC50 ranged from 2.5x105 to 3.33x105 ppm and 2.20x105 to 2.85x105 ppm in diet incorporation and surface contamination methods, respectively. The NCIM-5111 isolate exhibited the lowest LC50 of 2.5x105 ppm in diet incorporation and 2.2x105 ppm in the surface contamination method. Surface contamination method revealed more mortality of 6.66 to 10.00% across the NCIM isolates. All the isolates were further used for identification of insecticidal toxin (Vip, Cyt) genes, and it was observed that four NCIM isolates harbour the Vip3Aa1 gene and one viz., NCIM-5112 isolate carries the Vip1/ Vip2 gene, which has distinct motifs from the Vip toxins that are currently in use.
Publisher
The Entomological Society of India
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