Molecular characterization of cry/vip genes and efficacy of native bacillus thuringiensis isolates
| dc.contributor.advisor | M.S.Kuruvinashetty | |
| dc.contributor.author | Bisveswara Prasad Yadav | |
| dc.date.accessioned | 2016-10-18T09:06:46Z | |
| dc.date.available | 2016-10-18T09:06:46Z | |
| dc.date.issued | 2007 | |
| dc.description.abstract | Bacillus thuringiensis, a widely used biocontrol agent against insect pests, produces crystal proteins, which are toxic to many insects. 406 isolates were freshly made from soils of North Eastern hill region of Sikkim and Tripura. The predominant crystal type was spherical (41%) in Sikkim isolates, whereas in Tamil Nadu and Tripura isolates, bipyramidal (88.6%) and irregular (50%) types, respectively, were predominant. The presence of different cry/vip genes was determined in 106 isolates. One or more cry genes were detected in every isolate. Prevalent genes were cry2 in Sikkim (56.66%) and Tripura (59.37%) and cry4 in Tamil Nadu isolates (77.27%). Among vip genes; vip3A was most frequent (24.52%). Bioassay against Plutella xylostella, Crocidolomia binotalis, Spodoptera litura, Tribolium castenium and Atholia lugens proxima was done and none of the Sikkim and Tripura isolates were better than reference strain HD1 against 3rd instar larvae of P. xylostella. Many Tamil Nadu isolates were comparable to HD1 causing complete mortality. Against C. binotalis 3rd instar larvae, four Sikkim isolates were similar to the reference strain HD1 with 90 per cent mortality. But, three Tamil Nadu isolates causing 100 per cent mortality were superior. Against, T. castenium, S. litura and A. lugens proxima none of the isolates was effective. All the isolates, which were effective against DBM and cabbage leaf webber (>80% mortality) consisted of at least one known lepidopteran specific cry/vip gene, except TX 136 which had cry4 and cry28. cry10 specific primer gave a larger (615 bp) than expected (404 bp) amplicon in reference strain 4Q1. Cloning and sequencing showed that it is 98 per cent homologous to another reported cry10 partial cds (EF182766.1). Isolation, crystal identification and molecular characterization of cry/vip genes of different B. thuringiensis strains and their insecticidal bioassay is necessary to detect both known and novel cry genes. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/80768 | |
| dc.publisher | UAS, Dharwad | en_US |
| dc.research.problem | Molecular characterization of cry/vip genes and efficacy of native bacillus thuringiensis isolates | en_US |
| dc.sub | Plant Biotechnology | en_US |
| dc.theme | Molecular characterization of cry/vip genes and efficacy of native bacillus thuringiensis isolates | en_US |
| dc.these.type | M.Sc | |
| dc.title | Molecular characterization of cry/vip genes and efficacy of native bacillus thuringiensis isolates | en_US |
| dc.type | Thesis | en_US |