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Verma Prashant , R. T. Subburaju , N. Balakrishnan

Abstract

Objective: Aim of this work was to study the larvicidal activity of Artemisia nilagirica (Clarke) Pamp. and Ocimum sanctum Linn. against dengue, malaria, and filariasis transmitting mosquito larvae. Methods: The larvicidal activity of essential oil, chloroform, petroleum ether, and methanolic extracts of A. nilagirica and O. sanctum were tested against three different mosquito larvae viz., Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. Late third instar or early fourth instar larvae were selected for the screening. These extracts and essential oil were used for determining the larvicidal activity by using WHO method for evaluation of new larvicidal agent. Results: The result suggests larvicidal activity by essential oil, petroleum ether and chloroform extract of both the plants against all three selected mosquito species, while methanolic extract was found to be inactive up to 300 ppm. Among the essential oil and extracts of A. nilagirica and O. sanctum, essential oil of O. sanctum was found to be the most potent larvicide against C. quinquefasciatus and A. aegypti larvae, while A. nilagirica essential oil was more potent larvicide against A. stephensi larvae. Conclusion: The results suggest the use of the plants in insect control as an alternative method for minimizing the noxious effects of some pesticide compounds on the environment. Thus the essential oil of O. sanctum and A. nilagirica may deliver promising, more selective and biodegradable larvicidal agents.

Keywords

Aedes aegypti, Anopheles stephensi, Artemisia nilagirica, Culex quinquefasciatus, Larvicide, Ocimum sanctum

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N. Balakrishnan ¹

Affiliations
1 Supercomputer Education and Research Centre, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

No Abstract.

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N. Balakrishnan ¹

Affiliations
1 Indian Institute of Science, Bangalore, IN

Abstract

No Abstract.

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N. Balakrishnan ¹

Affiliations
1 Indian Institute of Science, Bangalore, IN

Abstract

No Abstract.

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N. Balakrishnan ¹

Affiliations
1 Indian Institute of Science, Bangalore, IN

Abstract

No Abstract.

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N. Balakrishnan ¹, R. K. Murali Baskaran ², N. R. Mahadevan ²

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, IN
2 Department of Agricultural Entomology, Agricultural College and Research Institute (TNAU), Madurai 625 104, Tamil Nadu, IN

Abstract

A study was undertaken to observe the combined effects of Trichogramma chilonis with some biopesticides viz., HaNPV, Bacillus thuringiensis var. kurstaki (HaIt WP) and Beauveria bassiana (Bev Bas). Two releases of T. chilonis with two sprays of B.t.k. recorded less mean larval popUlation (O.33/plant). less damage on shed squares (42.78%), intact squares (9.12%), bolls (14.20%) and loculi (10.68%) and recorded higher yield (782 kg/ha). Two releases of T. chilonis with two sprays of HaNPV was the next best treatment regarding less mean larval popUlation and damage on fruiting parts. Application of B. bassiana alone and in conjunction with T. chilonis proved less effective compared to other treatments. Two releases of T. chilonis with one spray of B.t.k or HaNPV and T. chilonis alone performed moderately in reducing the larval population and damage on fruiting parts.

Keywords

Biopesticides, Efficacy, Helicoverpa armigera, Trichogramma chilonis.

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N. Balakrishnan ¹, R. K. Murali Baskaran ², N. R. Mahadevan ²

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu, IN
2 Department of Agricultural Entomology, Agricultural College and Research Institute (TNAU), Madurai 625 104, Tamil Nadu, IN

Abstract

The present investigation was carried out to study the field efficacy of Chrysoperla carnea (Stephens) in combination with biopesticides against Helicoverpa armigera (Hiibner). The lowest mean larval population of H. armigera, minimum damage on shed squares, squares (intact), bolls and loculi and higher yield were recorded in two releases of C. carnea and two sprays of Bacillus thuringiensis var. kurstaki (B.t.k.) treated plots followed by C. cornea in conjunction with HaNPV and B.t.k alone treated plots. The field recovery of C. cornea, HaNPV infected, Bacillus thuringiensis var. kurstaki infected and Beauveria bassiana mycosed larvae was more in their respective alone treated plots. The incremental cost benefit ratio was obtained maximum in chlorpyriphos 20 EC alone (1: 3.66) followed by HaNPV alone (1: 3.S(), two releases of C. carnea with two sprays of HaNPV (1: 2.88) and two releases of C. carnea with one spray of HaNPV (1: 2.48).

Keywords

Biopeslicides, Chrysoperia carnea, Cotton, Helicoverpa armigera, ICBR.

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R. Manikandan ¹, P. Kanimozhi ¹, N. Balakrishnan ¹, V. Balasubramani ¹, D. Sudhakar ¹, V. Udayasuriyan ¹

Affiliations
1 Department of Plant Biotechnology, Centre for Plant Molecular Biology and Biotechnology, Tamil Nadu Agricultural University, Coimbatore (T.N.), IN

Abstract

A novel synthetic cry2AX1 gene was codon optimized and a sequence encoding cotton rbcS1b transit peptide was fused upstream of coding sequence. The fusion cry2AX1 gene, driven by maize ubiquitin1 promoter was cloned in a pUH plant transformation vector. Agrobacterium mediated transformation was carried out with pUH-ctp-2AX1 construct using leaf discs of tobacco as model plant. Screening by PCR revealed presence of cry2AX1 gene in all nine putative transformants and expression of cry2AX1 protein in PCR positive T₀ tobacco plants ranged from 1.5 to 10.0 ng/g. The detached leaf bit bioassay of tobacco transformants with Helicoverpa armigera showed 30 per cent mortality even at lower level of cry2AX1 expression. The results indicated a newly developed construct was functionally expressed in tobacco plant.

Keywords

Tobacco, Transformation, Insect Resistance, Helicoverpa armigera.

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N. Balakrishnan ¹, A. B. Panda ¹, N. R. Raj ¹, A. Shrivastava ¹, R. Prathani ¹

Affiliations
1 Technocrats Institute of Technology- Pharmacy, Bhopal-462021, IN

Abstract

Acalypha indica (Euphorbiaceae) is commonly known as Indian Copperleaf and Indian Nettle. It is a common annual herb, which grows in the hotter parts of India like Bihar, Assam and southwards of Kerala. The ethanol and aqueous extracts of ischolar_main were screened for antioxidant activity using Nitric Oxide Scavenging activity method, which showed significant percentage of inhibition in dose dependent manner. As antioxidant therapy is found to be useful in complicated disease status related with free radical activity, the present study might be extended for the formulation and evaluation of different antioxidant herbal dosage forms.

Keywords

Acalypha indica, Antioxidant, Nitric Oxide Scavenging Activity.

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K. V. Nayan Ganesh ¹, A. L. Reyaz ¹, N. Balakrishnan ¹

Affiliations
1 Department of Plant Biotechnology, Centre for Plant Molecular Biology and Biotechnology, Tamil Nadu Agricultural University, Coimbatore – 635110, Tamil Nadu, IN

Abstract

Bacillus thuringiensis Berliner (Bt) being an eco-friendly bioinsecticide is effectively used in pest management strategies and, therefore, isolation and identification of new strains effective against a broad range of target pests is important. In the present study, four indigenous Bt isolates (T489, T491, T495 and T532) were taken and investigated for their properties such as crystal morphology, cry gene(s) content and insecticidal activity. Bipyramidal, cuboidal and spherical crystals were observed. Among the four isolates only one isolate was found positive for lepidopteran specific cry genes. The isolate T532 which showed the presence of cry1, cry2Aa and cry2Ab genes was selected for protein profiling and bioassay. The isolate showed the presence of two proteins of molecular weights at ~135 and ~65 kDa sizes. Artificial diet based bioassay resulted in 100% mortality of the neonate larvae of H. armigera and S. litura for the isolate T532 which was comparable to that of the positive control (HD1). The full length cry2A gene was amplified and cloned into E. coli DH5α strain. The recombinant plasmids were sequenced and the sequence was deposited in GenBank nucleotide database. The accession number of the gene is MH475905. The gene was named by the Bacillus thuringiensis delta endotoxin nomenclature committee as cry2Aa23.

Keywords

Bacillus Thuringiensis, Cloning, Cry2Aa, PCR.

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