1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Ecofriendly pest management in brinjal (Solanum melongena L.)(Department of Entomology, College of Agriculture,Vellayani, 2000) Annie Bernice, T S; Krishnakumar, RA survey was conducted in the important brinjal growing tracts of Thiruvananthapuram district to study the population dynamics of the pests and their natural enemies in the brinjal ecosystem. Laboratory experiment and field experiments were conducted in the College of Agriculture, Vellayani to assess the deterrency and toxicity of the different treatments on aphids, epilachna and Leucinodes which were identified as important pests of brinjal from the survey and the effective treatments as identified from the laboratory experiment were carried out in the field. =<; Malathion alone or with garlic was found to be toxic to aphids. Epilachna and Leucinodes. The treatments with neem oil and Hyptis suaveolens either alone and in combination were found to have deterrent and toxic effects on aphids, Epilachna and Leucinodes in the laboratory experiment. However, the effect was much pronounced when neem oil activated with garlic was used in combination with Hyptis suaveolens. In the field, though malathion was found to contain the pests, the effect was not persistent for a long time and hence was not effective in the long run. The combination of neem oil + garlic plus Hyptis suaveolens was found to offer protection for the pest for a long period of time. On par with it were combination of nee m oil plus Hyptis suaveolens + garlic and combination of neem oil + H. suaveolens. The botanicals were also found to be safe for the natural enemies like coccinellids, staphylinids and spiders. This treatment was also found superior to other treatments in terms of net income and benefit cost ratio and the lower unit cost of the treatment with high yield was precisely the reason for its superiority.Item Taxonomy of predatory coccinellid beetles (Coccinellidae:coleoptera) in rice and vegetables(Department of Agricultural Entomology, College of Horticulture,Vellanikkara, 2003) Queno Jose; Haseena BhaskarMembers of the family Coccinellidae, commonly called as lady bird beetles and are predatory on a wide variety of pests. The grubs and adults of the beetle are voracious feeders of many sucking pests and effect natural control of pests in our crop fields. The diversity and abundance of predatory coccinellids in field crops are very much dependent on species and number of prey available. The present investigation entitled "Taxonomy of predatory coccinellid beetles (Coccinellidae : Coleoptera) in rice and vegetables was undertaken to study the taxonomy, species composition and diversity of coccinellid predators in rice and vegetable fields of Vellanikkara and to develop an up to date key for identifying them. Survey was conducted at vegetable fields of College of Horticulture and farmers fields, Vellanikkara and rice fields at Agricultural Research Station, Mannuthy. From the various fields surveyed, sixteen species of coccinellids were collected. Associated with the aphid, Aphis craccivora, ten species of coccinellids were recorded from cowpea fields. Four species of coccineIlids each were reported from coccinia and bittergourd fields. In brinjal, three species of coccineIlids were recorded on mealy bug C. insolitus. Only one species was recorded in bhindi feeding on Aphis gossypii. They were included in four subfamilies, viz., Sticholotidinae, Coccirrellinae, Chilocorinae and Scyrnninae in five tribes and ten genera Taxonomic characters of 11 species collected were studied, namely, Jauravia soror of the subfamily Sticholotidinae, Coccinella transversalis, Q Cheilomenes sexmaculata, Micraspis discolor, Harmonia octomaculata and Anegleis cardoni of the subfamily Coccinellinae, Brumoides suturalis of Chilocorinae and Scymnus (Pullus) coccivora, S. (P) pyrocheilus, S. (P) latemaculatus and Pseudaspidimerus trinolatus of the subfamily Scymninae. A detailed key for all the species studied is prepared by the author. J dorsalis and J pallidula of tribe• Sticholotidinae, s. (P.) coccivora and Pseudoscymnus sp. of Scyrnninae are new records from Kerala. The present study I has also revealed new prey records from Kerala: S. (P.) pyrocheilus and S. (P.) latemaculatus on A. gossypii and A. craccivora; J. dorsalis, J. pallidula. on A. gossypii; P. trinotatus on C. insolitus and A. gossypii . . ' Of the total 400 species of coccinellids reported from India only 16 species were recorded in the present study from rice and vegetable fields. With the diverse flora and fauna characteristic to Kerala, there is wider scope to explore the species diversity of coccinellids in this region,:Item Molecular cloning and characterisation of coat protein gene of banana bract mosaic virus(Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara, 2016) Darshan Gowda, M R; Anita Cherian, KBanana (Musa spp.), identified as ‘tropical treasure’ is grown extensively in the tropical and sub tropical regions of the world. Diseases, especially those caused by viruses are major constraints for the profitable cultivation of banana. Among the viral diseases, banana bract mosaic is one of the most important, which leads to an yield reduction ranging from 52 to 75 per cent. This disease is caused by Banana bract mosaic virus (BBrMV) which is a member of genus Potyvirus and family Potyviridae. In case of any viral disease, early diagnosis is very important since symptomless hosts carry the viral inoculum. Development of molecular clones of viral genome has immense application in the field of disease diagnostics and management. Hence, the present study was carried out with the objective to develop molecular clones of coat protein (CP) gene of BBrMV and to characterize it.The infected suckers were collected from Banana Research Station (BRS), Kannara and maintained in the insect proof net house of Department of Plant Pathology. The symptoms developed on different plant parts under natural field conditions were documented which included longitudinal, irregular, reddish streaks of varying sizes on the base of pseudostem, mosaic pattern on bracts, fan like orientation of leaves, spindle shaped lesions on leaves, reduced bunch size and malformed fingers.The serodiagnostic technique namely, Direct Antigen Coating-Enzyme linked immuno sorbent assay (DAC-ELISA) was validated by determining the antibody titre with different dilutions of primary antibody viz., 1:100, 1:200, 1:300, 1:500 and it was found that BBrMV could be best detected at 1:200 dilution along with 1:500 dilution of secondary antibody. Later, the presence of virus particles in the samples were confirmed by DAC-ELISA using the standardized combination of primary and secondary antibody dilutions. Dot Immuno Binding Assay (DIBA) was validated to detect BBrMV and showed positive reaction for infected leaf sample which was detected by the development of purple coloured spots on nitrocellulose membrane.The genome of BBrMV is RNA and hence, molecular detection of virus was standardized by Reverse Transcription- PCR (RT-PCR). Total RNA was isolated by two different protocols using different reagents. Among the two methods, the one with Ambion Purelink RNA Reagent was the most appropriate for RNA isolation from banana since it provided highest quality and quantity of RNA compared to the protocol with TRIzol reagent. The isolated RNA was converted into complementary DNA (cDNA) using First Strand cDNA synthesis kit. RTPCR amplification of coat protein gene was standardized using gene specific reported primer (B1/B2) and designed primer (BCPF1/R1) which yielded amplicons of approximate size, 605 bp and 850 bp respectively. The molecular cloning of CP gene was done in Escherichia coli (DH5- alpha). The presence of gene insert in transformed colonies were confirmed by colony PCR using plasmid specific primer (T7 and SP6) which yielded amplicons of expected band size of 1150 bp. The amplified colony PCR products were sequenced to obtain CP gene sequence of BBrMV. The characterization of cloned CP gene of BBrMV was carried out by in silico analysis. The blast analysis revealed that the CP gene sequence of the virus showed maximum homology of 99 per cent to KER2 isolate from Kasargod, Kerala (Accession no. KF385491). The sequence exhibited significant nucleotide identity (99 to 96 per cent) and amino acid identity (95 to 83 per cent) with other nucleotide and protein sequences of BBrMV available in the database of Genbank. The phylogenetic analysis by the alignment of CP gene sequences of selected 22 isolates also revealed that the present isolate was more similar to KER2 isolate and the Indian isolates did not show any relationship based on geographical origin.The recombinant clones developed in the present study could be applied in serodiagnosis and genetic engineering. This could be also used as disease diagnostic probes for more sensitive molecular diagnostic techniques like Nucleic acid spot hybridization.