Browsing by Author "Srinivasa Narayana"

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A simple PCR-based quick detection of the economically important oriental fruit fly, Bactrocera dorsalis (Hendel) from India
(Frontiers Media SA, 2024) Varun Arya; Srinivasa Narayana; Twinke Sinha; Aravindaram Kandan; Samantapudi Venkata Satyanarayana Raju
The oriental fruit fly, Bactrocera dorsalis (Hendel), is a significant economic and quarantine pest due to its polyphagous nature. The accurate identification of B. dorsalis is challenging at the egg, maggot, and pupal stages, due to lack of distinct morphological characters and its similarity to other fruit flies. Adult identification requires specialized taxonomist. Existing identification methods are laborious, time consuming, and expensive. Rapid and precise identification is crucial for timely management. By analyzing the variations in the mitochondrial cytochrome oxidase-1 gene sequence (Insect barcoding gene), we developed a species-specific primer (SSP), DorFP1/DorRP1, for accurate identification of B. dorsalis. The optimal annealing temperature for the SSP was determined to be 66°C, with no cross-amplification or primer-dimer formation observed. The SSP was validated with B. dorsalis specimens from various locations in northern and eastern India and tested for cross-specificity with six other economically significant fruit fly species in India. The primer specificity was further confirmed by the analysis of critical threshold (Ct) value from a qPCR assay. Sensitivity analysis showed the primer could detect template DNA concentrations as low as 1 pg/µl, though sensitivity decreased at lower concentrations. Sequencing of the SSP-amplified product revealed over >99% similarity with existing B. dorsalis sequences in the NCBI GenBank. The developed SSP reliably identifies B. dorsalis across all developmental stages and sexes. This assay is expected to significantly impact pest identification, phytosanitary measures, and eradication programs for B. dorsalis. Copyright © 2024 Arya, Narayana, Sinha, Kandan and Satyanarayana Raju.
Advances in Insect Resistance Breeding against Brown Planthopper and Gall Midge in Rice
(Springer Nature, 2022) Aishwarya Ray; G. Basana Gowda; Naveen Kumar B. Patil; Guru Pirasanna Pandi; Totan Adak; Haramohan Pradhan; Srinivasa Narayana; Prakash Chandra Rath
There is always a silent war ongoing between the plants and the insects, and during the long run, the insects emerge triumphant. Time and tide the pest management tactics such as chemical usage although manage the pest to a certain level but they also sometimes hamper the natural enemies that bring down the pest population. Indiscriminate usage of insecticides also results in developing adaptation to the particular toxic compound. Similar is the case of host plant resistance. Their adaptation is rapid, thus leading to the breakdown of resistance. Hence, there is a need to incorporate the molecular and the genetic tools that will confer resistance against inexorable pest. The molecular approach such as subduing of serotonin biosynthesis and instigating the mitogen-activated protein kinases (MAPK) in cereal crops such as rice affects the feeding behavior of the insects triggering a defense response. Similarly in gall midge, 11 R (Gm1 to Gm11) genes and seven distinct biotypes have been characterized in the tropics like India. Breeding programs for gall midge resistance have shown promise due to monogenic nature of resistance. These advances in rice genetics have opened new avenues for the development of genetically engineered plants a stable pest management approach. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.
Development of a loop-mediated isothermal amplification assay for accurate and rapid identification of Spodoptera frugiperda in maize from India
(Akademiai Kiado ZRt., 2024) Twinkle Sinha; Srinivasa Narayana; Varun Arya; Aravindaram Kandan; Samantapudi Venkata Satyanarayana Raju; Ipsita Samal
The fall armyworm, Spodoptera frugiperda, is an invasive and serious polyphagous crop pest that damages around 353 plants belonging to 72 plant families around the world. It has a global distribution and serious pest status around the world. Identification of this pest at early instar is difficult due to morphological similarity with other Spodoptera spp. For the control and management of this pest, rapid identification method is required. We developed a novel and rapid assay based on loop-mediated isothermal amplification (LAMP) utilizing mitochondrial Cytochrome Oxidase I gene (COX I). The species-specific primers for S. frugiperda were designed, and the LAMP specificity was cross-checked with five other closely related species of moths and found that only S. frugiperda yielded positive results among others within 45 min at 65℃. The LAMP sensitivity test showed that the lowest concentration of genomic DNA required for this assay is 100 fg, much less than compared to normal polymerase chain reaction where 1 ng is required. This assay can be performed on any heating block without the use of visualization on an agarose gel-based method. Further, validation using simple DNA extraction protocols proved that our developed primers will identify species within 30 min and are suitable for on-spot field detection. Here a new cost-effective, rapid and highly sensitive method is represented, which is very useful for the detection of invasive pests in quarantine stations as well as for improving pest management strategies in agriculture fields toward sustainable crop production. © Akadémiai Kiadó Zrt. 2023.
Diagnosis, taxonomic keys, DNA barcoding and molecular phylogeny of economically important fruit fly species (Diptera;Tephritidae)
(Springer Nature, 2024) Vishrutha Chandrashekhar; Varun Arya; Karamakodu Jacob David; Srinivasa Narayana
Fruit flies pose significant threats to horticultural crops, causing considerable production loss domestically and holding global importance as quarantine pests. Accurate identification is crucial for effective management and regulation of these pests. Hence, this study sought to explore species diversity and characterize fruit flies using both molecular and morphological approaches across different regions of Uttar Pradesh (UP) state in India. Fruit flies were captured using different parapheromone-based bottle traps containing methyl eugenol and cue-lure as male attractants, as well as fruit-based baits, over a period of 11 weeks. Nine fruit fly species were recorded, namely Bactrocera dorsalis, B. correcta, B. divenderi, B. digressa, B. zonata, Zeugodacus cucurbitae, Z. tau, Z. caudatus, and Z. duplicatus and their identities were confirmed through morphological examination and DNA barcoding. B. divenderi was recorded for the first time from the state UP. B. divenderi and Z. duplicatus barcodes were submitted for the first time to the NCBI database. All the nine species were diagnosed and taxonomic keys were provided for identification. The study of fruit fly diversity and abundance indicated lesser fruit fly diversity in the study area. The COI genes found to be suitable for identification of fruit flies without ambiguity. The pairwise genetic distance is also calculated for the fruit fly species described. The maximum likelihood tree depicts two different clades for Zeugodacus and Bactrocera which is similar to the results of pairwise genetic distance. This documentation of species diversity provides valuable insights for future research and aids in monitoring the distribution of fruit flies, including potential invasive species. © African Association of Insect Scientists 2024.
DNA barcoding of fruit flies associated with cucurbit ecosystem and combination of Cue-Lure and Methyl Eugenol in trap is not effective for mass trapping of responsive fruit flies
(Springer Science and Business Media B.V., 2022) Varun Arya; Srinivasa Narayana; Saniya Tyagi; Samantapudi Venkata Satyanarayana Raju; Chandra Prakash Srivastava; Twinkle Sinha; Pratap Divekar
Fruit flies are key pests of vegetable crops, particularly cucurbits. Depending on the fruit fly species, the parapheromone, cue-lure (CL) or methyl eugenol (ME) is used in traps for monitoring and mass trapping. Many species of fruit flies belong to the genus Bactrocera and Zeugodacus which infest cucurbits and are responsive to CL and ME. Preparation and application of individual lures of CL and ME is uneconomical and laborious. Therefore, the present investigation was undertaken to document fruit flies associated with the cucurbit ecosystem, their diversity using CL and ME baited traps and to study the feasibility of combination of CL and ME in the trap for mass trapping of responsive fruit flies. Six species of fruit flies were found to be associated with the cucurbit ecosystem, viz., Zeugodacus cucurbitae, Z. tau, Bactrocera dorsalis, B. zonata, B. digressa and B. correcta. These species were identified using taxonomic keys and DNA barcoding. Bactrocera digressa was recorded for the first time from Uttar Pradesh (India) and it is also attractive to both CL and ME. The mitochondrial cytochrome oxidase I barcodes of B. digressa are novel to India. Though six species were collected in the lures, it was Z. cucurbitae and Z. tau that actually infested cucurbits, ascertained from fruit fly emergence from infested cucurbits, indicating the seriousness of pests. The population of Z. cucurbitae and B. dorsalis was found to be more in CL (p = 0.03308) and ME (p = 0.0159) respectively than in the ME/CL combination. The study thus indicated that the combined use of lures, CL and ME in single trap significantly reduces the trap catches of responsive fruit flies. The phylogenetic analysis revealed two distinct clades, i.e., one for fruit flies responsive to CL and another one for ME. Our findings are anticipated to have significant implications for pest identification, monitoring and management. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.
Migratory behaviour of Brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), in India as inferred from genetic diversity and reverse trajectory analysis
(Springer Science and Business Media Deutschland GmbH, 2022) Saniya Tyagi; Srinivasa Narayana; R.N. Singh; C.P. Srivastava; S. Twinkle; Sanat Kumar Das; Mallikarjuna Jeer
The brown planthopper, Nilaparvata lugens (Stål) is a major sucking insect pest of rice. This insect has long been considered as migratory; however, its route in India is still unknown. Hence, to find out its migration route genetic diversity, genetic structure and gene flow of 16 N. lugens populations from major rice growing regions of India was studied based on mitochondrial cytochrome oxidase I (COI). The results revealed a high genetic homogeneity among the populations on the basis of genetic diversity statistics and neutrality tests. There was a prevalence of a single major haplotype across the country. No spatial relevance was found with the genetic structure of the populations indicating presence of excessive gene flow among them. Extensive gene flow among populations was also confirmed with the presence of higher number of immigrants in North, Central, and East India. To further clarify the migration sources, 48 h air-mass reverse trajectory was performed for Varanasi just aftermath of cyclones Amphan and Yaas, which disclosed Eastern/Northeastern states along with Bangladesh and Myanmar as the possible source areas. Overall, the results revealed a single panmictic homogeneous population of N. lugens in India with extensive gene flow as a consequence of their migration. These findings will help in better forecasting enabling efficient regional management of this important rice pest. © 2022, King Abdulaziz City for Science and Technology.
Molecular Insights into Wing Polymorphism and Migration Patterns of rice Planthoppers
(Springer Nature, 2022) Saniya Tyagi; Srinivasa Narayana; Rajendra Nath Singh; G. Basana Gowda
Planthoppers are major plant pests in several cultivated ecosystems worldwide. In most situations, like the rice ecosystems in Asia, they represent a complex of cryptic species. They inflict direct as well as indirect damage on rice by serving as disease-causing virus vectors. Planthoppers are seasonal migrants, of which economically important pests, such as Nilaparvata lugens, Sogatella furcifera, and Laodelphax striatellus, show wing dimorphism. Long-winged morphs are suitable for long-distance migration, while short-winged morphs for local colonization. The wing polyphenism is regulated by environmental cues, host plant nutrition, and other abiotic factors. Juvenile hormone, miRNA, insulin receptors pathway, and 20-hydroxy ecdysone form an autoregulatory feedback loop to regulate wing polyphenism in N. lugens. In India and other countries in Southeast Asia, rice planthoppers are seasonal migrants from south to north. Specifically, Indochinese peninsular region is the main source of N. lugens migratory population to temperate part of China and most probably to Japan. Similarly, the Greater Mekong Subregion (GMS) is the source of migratory population of S. furcifera to Yunan province of China. Migratory pathways of planthoppers have been elucidated efficiently with nuclear (simple sequence repeats, single nucleotide polymorphism) markers, mitochondrial (MtCo1) markers, and recently with more powerful whole-genome sequencing by evaluating genetic structure of different populations. Understanding migratory behavior of planthoppers will help in developing effective pest management strategies. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.
Plant Secondary Metabolites as Defense Tools against Herbivores for Sustainable Crop Protection
(MDPI, 2022) Pratap Adinath Divekar; Srinivasa Narayana; Bhupendra Adinath Divekar; Rajeev Kumar; Basana Gowda Gadratagi; Aishwarya Ray; Achuit Kumar Singh; Vijaya Rani; Vikas Singh; Akhilesh Kumar Singh; Amit Kumar; Rudra Pratap Singh; Radhe Shyam Meena; Tusar Kanti Behera
Plants have evolved several adaptive strategies through physiological changes in response to herbivore attacks. Plant secondary metabolites (PSMs) are synthesized to provide defensive functions and regulate defense signaling pathways to safeguard plants against herbivores. Herbivore injury initiates complex reactions which ultimately lead to synthesis and accumulation of PSMs. The biosynthesis of these metabolites is regulated by the interplay of signaling molecules comprising phytohormones. Plant volatile metabolites are released upon herbivore attack and are capable of directly inducing or priming hormonal defense signaling pathways. Secondary metabolites enable plants to quickly detect herbivore attacks and respond in a timely way in a rapidly changing scenario of pest and environment. Several studies have suggested that the potential for adaptation and/or resistance by insect herbivores to secondary metabolites is limited. These metabolites cause direct toxicity to insect pests, stimulate antixenosis mechanisms in plants to insect herbivores, and, by recruiting herbivore natural enemies, indirectly protect the plants. Herbivores adapt to secondary metabolites by the up/down regulation of sensory genes, and sequestration or detoxification of toxic metabolites. PSMs modulate multi-trophic interactions involving host plants, herbivores, natural enemies and pollinators. Although the role of secondary metabolites in plant-pollinator interplay has been little explored, several reports suggest that both plants and pollinators are mutually benefited. Molecular insights into the regulatory proteins and genes involved in the biosynthesis of secondary metabolites will pave the way for the metabolic engineering of biosynthetic pathway intermediates for improving plant tolerance to herbivores. This review throws light on the role of PSMs in modulating multi-trophic interactions, contributing to the knowledge of plant-herbivore interactions to enable their management in an eco-friendly and sustainable manner. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Role of DNA Barcoding in Integrated Pest Management: Challenges and Threats
(Springer International Publishing, 2022) Manish Chandra Mehta; Srinivasa Narayana; Raghuraman Mahadevan
[No abstract available]