150 results on '"Ramasamy, Srinivasan"'
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2. Draft genome sequence of antibiotic-resistant Shigella flexneri MTR_GR_V146 strain isolated from a tomato (Solanum lycopersicum) sample collected from a peri-urban area of Bangladesh.
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Islam, Md Saiful, Pramanik, Pritom, Rana, Md, Ullah, Md, Neloy, Fahim, Ramasamy, Srinivasan, Schreinemachers, Pepijn, Oliva, Ricardo, and Rahman, Md
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ARGs ,Bangladesh ,Shigella flexneri ,VFGs ,draft genome ,gardening systems ,public health ,vegetables - Abstract
This study announces the genome sequence of the Shigella flexneri MTR_GR_V146 strain isolated from a tomato (Solanum lycopersicum) sample in Bangladesh. This strain has a 4,624,521 bp genome length (coverage: 73.07×), 2 CRISPR arrays, 1 plasmid, 52 predicted antibiotic resistance genes, and 53 virulence factor genes.
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- 2024
3. Draft genome sequence of multidrug-resistant Citrobacter freundii MTR_GS_V1777 strain isolated from a spinach (Spinacia oleracea) sample in Gazipur, Bangladesh.
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Pramanik, Pritom, Rana, Md, Ramasamy, Srinivasan, Schreinemachers, Pepijn, Oliva, Ricardo, Rahman, Md, and Islam, Md Saiful
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Bangladesh ,Citrobacter freundii ,gardening system ,multidrug resistance ,vegetable ,virulence ,whole genome - Abstract
We announce a genome sequence of Citrobacter freundii MTR_GS_V1777 strain isolated from a vegetable sample in Bangladesh. This strain had a genome size of 4,997,753 bp (58.7× genome coverage) and contained two plasmids, typed as sequence type ST124, 38 predicted antibiotic resistance genes, and 77 predicted virulence factor genes.
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- 2024
4. Draft genome sequences of five multidrug-resistant Escherichia coli strains isolated from vegetable samples in Bangladesh.
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Pramanik, Pritom, Rana, Md, Ramasamy, Srinivasan, Schreinemachers, Pepijn, Oliva, Ricardo, Rahman, Md, and Islam, Md Saiful
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Bangladesh ,Escherichia coli ,MDR ,antibiotic resistance genes ,gardening systems ,public health ,vegetables ,virulence factor genes ,whole-genome sequencing - Abstract
Reports indicate that vegetables are becoming a source of multidrug-resistant (MDR) bacteria, including Escherichia coli. Here, we present genome sequences of five MDR E. coli strains to assist future genomic analysis of this bacterium. These E. coli strains were isolated from vegetable samples of different gardening systems in Dhaka, Bangladesh.
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- 2024
5. Soil bacteriome diversity and composition of rooftop and surface gardens in urban and peri-urban areas of Bangladesh
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Rana, Md. Liton, Hoque, M. Nazmul, Rahman, M. Shaminur, Pramanik, Pritom Kumar, Islam, Md. Saiful, Punom, Sadia Afrin, Ramasamy, Srinivasan, Schreinemachers, Pepijn, Oliva, Ricardo, and Rahman, Md. Tanvir
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- 2024
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6. Evaluation of Integrated Pest and Disease Management Combinations against Major Insect Pests and Diseases of Tomato in Tamil Nadu, India
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Sankaran Pagalahalli Shanmugam, Marimuthu Murugan, Mookiah Shanthi, Thiyagarajan Elaiyabharathi, Kathithachalam Angappan, Gandhi Karthikeyan, Gopal Arulkumar, Palanisamy Manjari, Manickam Ravishankar, Paola Sotelo-Cardona, Ricardo Oliva, and Ramasamy Srinivasan
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grafted tomato ,microbial pesticides ,botanicals ,pheromone traps ,IPDM ,Plant culture ,SB1-1110 - Abstract
Tomatoes are one of the predominant vegetable crops grown throughout the year in Tamil Nadu, India. Their perishable nature and resource-intensive cultivation make them susceptible to biotic stress. The damage caused by invasive insect pests, bacterial wilt during the rainy season, and viral diseases are major yield-limiting factors, and the farmers mostly depend on calendar-based insecticide applications for insect pest and disease management in tomatoes. The desired tomato hybrids grafted onto bacterial wilt-resistant eggplant rootstocks offer protection against bacterial wilt during the rainy season. The integrated pest and disease management (IPDM) practices consist of resistant grafted tomato seedlings (wild eggplant rootstocks EG 203 and TS 03), bioinoculants (Bacillus subtilis + Trichoderma asperellum + Purpureocillium lilacinum), pheromone traps (Phthorimaea absoluta and Helicoverpa armigera), botanicals (azadirachtin), microbial pesticides (Bacillus thuringiensis, Metarhizium anisopliae, and Beauveria bassiana), and bio-rationals, which were evaluated in four locations in two major tomato-growing tracts of Tamil Nadu. The results revealed that the treatment EG 203 eggplant rootstock-grafted tomato along with IPDM practices performed better across all experimental locations than the other treatment combinations viz., TS 03 eggplant rootstock-grafted tomato + IPDM, tomato + IPDM, grafted tomato + farmers’ practice and tomato + farmers’ practice. The EG 203-grafted tomato recorded a higher yield than the farmers’ practice with significantly superior biometric parameters. The treatment of EG 203-grafted tomato and IPDM practices can be adopted for safer tomato production by enabling a reduction in pesticide applications while enhancing productivity.
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- 2024
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7. Potential food safety risks in tomato value chains in urban settings of Eastern Ethiopia: a qualitative investigation
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Kebede Amenu, Bekele Megersa, Megarsa Bedasa Jaleta, Getachew Dinede, Hable Worku, Kemal Kasim, Mukerem Taha, Abdulmuen M. Ibrahim, Jafer Kedir, Lina Mego, Kristina Roesel, Ralph Roothaert, Ramasamy Srinivasan, Delia Grace, and Theodore Knight-Jones
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food safety risk ,hygienic practices ,food market ,vegetable value chain ,tomato ,food transport ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
BackgroundThe value chains of tomatoes in Ethiopia are largely informal which may pose potential food safety risks. Value chains (VCs) mapping was carried out with emphasis on tomatoes in two major cities in eastern Ethiopia—Harar and Dire Dawa—which were assessed to identify practices likely to result in unsafe food, considering production, transportation, retail, preparation, and consumption.MethodsQualitative methods were used to map the VCs to understand the flows, actors, and practices. Group discussions and key informant interviews were performed to better understand the processes, practices, beliefs, and food safety risks in these VCs.ResultsThe two cities are supplied by two vegetable VCs: the first and larger being from distant producers in central Ethiopia, and the second from surrounding rural and peri-urban producers. The long-distance VCs involve producers, brokers, transporters, wholesalers, retailers, and consumers. The local producers, however, bring their fresh products directly to the cities without the involvement of VC actors other than final retailers and consumers. The study suggests microbiological contamination risks along tomato VCs, potentially including soil contamination, use of sewerage-contaminated irrigation water, untreated manure, unhygienic handling and storage conditions, and dirty contact surfaces during transportation and retailing. Tomatoes are mostly harvested by hand picking, collected, and sorted on the ground exposing to sunlight and physical bruising with potential contamination. More importantly, tomatoes are widely consumed raw without “a kill-step” that certainly contributes to food-borne infections. Suggestions by study participants for improving food safety and hygiene include funding toward improved infrastructure and facilities in the sectors, supporting VC actors with improved technology for quality production, and increasing awareness of good and hygienic practices. Consumers were particularly concerned about contamination with agrochemicals without much emphasis on the potential microbial contaminants. Fresh tomatoes are prepared in a variety of ways and are often consumed raw or slightly cooked. Further recommendations included using health extension workers to conduct awareness campaigns on improved food safety and hygienic practices.ConclusionThe qualitative VC mapping generated useful information for designing intervention strategies, especially targeting developing food safety interventions and an awareness communication campaign.
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- 2023
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8. Boswellia serrata-mediated zinc oxide nanoparticles-coated cotton fabrics for the wound healing and antibacterial applications against nosocomial pathogens
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Vakayil, Ramsi, Ramasamy, Srinivasan, Alahmadi, Tahani Awad, Almoallim, Hesham S., Natarajan, Nandakumar, and Mathanmohun, Maghimaa
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- 2022
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9. Assessment of pesticide residues in vegetables produced in central and eastern Ethiopia
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Getachew Dinede, Wubetu Bihon, Lina Gazu, Serge Foukmeniok Mbokou, Sisay Girma, Ramasamy Srinivasan, Ralph Roothaert, Delia Grace, Habtamu Gashaw, and Theodore J. D. Knight-Jones
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Ethiopia ,maximum residue level ,organochlorines ,organophosphates ,pesticide residues ,vegetables ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
BackgroundIn Ethiopia, pesticides are widely used in vegetable production. However, if used incorrectly they may harm consumers of vegetables contaminated with pesticide residues, as well as producers handling the pesticides and lead to ecological damage. We performed a cross-sectional survey to assess pesticide residues in vegetables produced in central and eastern Ethiopia.MethodsA total of 232 vegetable samples (91 tomatoes, 106 cabbages and 35 Swiss chard) were collected from fields and retail markets, and were screened for 35 pesticides (16 organochlorine, 11 organophosphate, 3 pyrethroids, 2 carbamates and 3 other agrochemicals) using GC–MS analysis.ResultsPesticides residues were detected in 60% of Swiss chard, 47% of cabbage and 45% of tomato samples. Two or more pesticides were detected in 20% of cabbages, 13% of tomatoes and over half of Swiss chard samples. Bendiocarb, diazinon, endrin, piperonyl butoxide, profenofos and propargite were detected, but only diazinon, propargite and profenofos had residual values above EU Maximum Residue Level (MRL), with diazinon commonly detected at relatively high levels. About 15% of the total analyzed samples, 10% of cabbages and tomatoes, and nearly half of Swiss chard samples had pesticide concentration exceeding EU MRL. However, none of the tested samples had residues exceeding Codex Alimentarius Commission (Codex) MRLs.ConclusionThis study showed widespread contamination of vegetables with pesticides, mainly organophosphates. We recommend monitoring and regulation of pesticides usage, with promotion of good agricultural practices.
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- 2023
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10. The continued effects of COVID-19 on the lives and livelihoods of vegetable farmers in India.
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Sandhya S Kumar, Pepijn Schreinemachers, Arshad Ahmad Pal, Ravishankar Manickam, Ramakrishnan M Nair, Ramasamy Srinivasan, and Jody Harris
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Medicine ,Science - Abstract
India experienced a rapid rise in COVID-19 infections from March 2021. States imposed varying levels of lockdowns and curfews to curb the spread of the disease. These restrictions severely affected the functioning of food systems. The objective of this study was to analyze how COVID-19 continues to affect agricultural production, food security and household diets of vegetable farmers. A phone-based survey was conducted with 595 vegetable farmers in the states of Andhra Pradesh, Assam, Jharkhand, Karnataka and Odisha, 60% of whom had been interviewed a year earlier. Overall, 60% of farmers experienced decreased vegetable production; over 80% reported a reduction in consumption of at least one food group; and 45% reported some level of food insecurity between May 2020 and May 2021. Farmers who reported decreased staples production, difficulty accessing seeds/seedlings, or reduced their household spending were more likely to report decreased vegetable production. Vegetable consumption was positively associated with receipt of COVID-19 relief benefits, borrowing money, or having home gardens. Farmers who received public agricultural assistance, or had reduced expenses, were more likely to have lower vegetable consumption. Greater severity of food insecurity was associated with farmers belonging to underprivileged social groups, non-Hindus, or those who experienced decrease in livestock production, weather related disruptions or received COVID-19 assistance. This is one of few studies that have conducted a longitudinal assessment of the impacts across multiple waves of COVID-19. COVID-19 is seen to be one among several shocks experienced by farm households, and exacerbated existing issues within agriculture and food security. There is a need for public policy support to strengthen both production and consumption of vegetables.
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- 2023
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11. Boosting Tomato Resilience in Tanzania: Grafting to Combat Bacterial Wilt and Abiotic Stress
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Msabila, Shem Elias, primary, Nordey, Thibault, additional, Ernest, Zablon, additional, Mlowe, Nickson, additional, Manickam, Ravishankar, additional, Ramasamy, Srinivasan, additional, and Huat, Joël, additional
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- 2024
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12. Draft genome sequence of antibiotic-resistantShigellaflexneri MTR_GR_V146 strain isolated from a tomato ( Solanum lycopersicum ) sample collected from a peri-urban area of Bangladesh
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Islam, Md. Saiful, primary, Pramanik, Pritom Kumar, additional, Rana, Md. Liton, additional, Ullah, Md. Ashek, additional, Neloy, Fahim Haque, additional, Ramasamy, Srinivasan, additional, Schreinemachers, Pepijn, additional, Oliva, Ricardo, additional, and Rahman, Md. Tanvir, additional
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- 2024
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13. Progeny fitness determines the performance of the parasitoid Therophilus javanus, a prospective biocontrol agent against the legume pod borer
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Djibril Aboubakar Souna, Aimé Hippolyte Bokonon-Ganta, Marc Ravallec, Mesmin Alizannon, Ramasamy Srinivasan, Barry Robert Pittendrigh, Anne-Nathalie Volkoff, and Manuele Tamò
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Medicine ,Science - Abstract
Abstract Therophilus javanus (Bhat & Gupta) is an exotic larval endoparasitoid newly imported from Asia into Africa as a classical biological control agent against the pod borer Maruca vitrata (Fabricius). The parasitoid preference for the five larval instars of M. vitrata and their influence on progeny sex ratio were assessed together with the impact of larval host age at the time of oviposition on development time, mother longevity and offspring production. In a choice situation, female parasitoids preferred to oviposit in the first three larval instars. The development of immature stages of the parasitoid was observed inside three-day-old hosts, whereby the first two larval instars of T. javanus completed their development as endoparasites and the third larval instar as ectoparasite. The development time was faster when first larval instars (two- and three-day-old) of the host caterpillars were parasitized compared to second larval instar (four-day-old). The highest proportion of daughters (0.51) was observed when females were provided with four-day-old hosts. The lowest intrinsic rate of increase (r) (0.21 ± 0.01), the lowest rate of increase (λ) (1.23 ± 0.01), and the lowest net reproductive rate (Ro) (35.93 ± 6.51) were recorded on four-day-old hosts. These results are discussed in the light of optimizing mass rearing and release strategies.
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- 2021
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14. Performance of Wild Tomato Accessions and Elucidation of Resistance against Invasive Pest Phthorimaea absoluta Damage under Tropical Conditions
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Pritha Ghosh, K. S. Jagadish, M. G. Purushothama, Peter Hanson, Mohamed Rakha, Paola Sotelo-Cardona, Sridhar Vaddi, and Ramasamy Srinivasan
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antibiosis ,antixenosis ,choice and no-choice assay ,host-plant resistance ,larval mortality ,Plant culture ,SB1-1110 - Abstract
Invasive tomato leaf miner, Phthorimaea absoluta causes serious damage and yield loss in tomato production in open-field and protected cultivation. Use of chemical pesticides is uneconomical and adversely affects humans and the environment. Host-plant resistance is an effective, economical and eco-friendly alternative to chemical pesticides. In this study, four wild tomato accessions from the World Vegetable Center along with one susceptible check were evaluated for their antixenosis and antibiosis effects on P. absoluta. The accessions VI037241 (Solanum galapagense) and VI037240 (S. cheesmaniae) were highly resistant, leading to 85% larval mortality under no-choice conditions. Choice assay also showed less oviposition preference and reduced pupal weight. Both VI037241 and VI037240 showed the highest resistance under field conditions. The accessions of S. habrochaites (LA1777) and S. habrochaites var. glabratum (VI030462) demonstrated moderate resistance against P. absoluta. Wild accessions recorded significantly less eggs and leaf damage in field trials compared to the susceptible genotype, S. lycopersicum (CL5915). Trichome density, type and higher production of acylsugar contributed to the insect resistance. Acylsugar production in wild accessions was less during the rainy season but significantly higher than in susceptible genotype. These findings can be useful to develop P. absoluta-resistant tomato varieties in tropics.
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- 2023
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15. Publisher Correction: Oviposition preference not necessarily predicts offspring performance in the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) on vegetable crops
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Sotelo-Cardona, Paola, Chuang, Wen-Po, Lin, Mei-Ying, Chiang, Ming-Yao, and Ramasamy, Srinivasan
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- 2021
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16. Oviposition preference not necessarily predicts offspring performance in the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) on vegetable crops
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Sotelo-Cardona, Paola, Chuang, Wen-Po, Lin, Mei-Ying, Chiang, Ming-Yao, and Ramasamy, Srinivasan
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- 2021
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17. Estimation of soil loss by USLE Model using Remote Sensing and GIS Techniques - A Case study of Coastal Odisha, India
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Ramasamy Srinivasan, Surendra Kumar Singh, Dulal Chandra Nayak, Rajendra Hegde, and Muniasami Ramesh
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Soil erosion risk ,land use ,Remote sensing ,GIS ,coastal Odisha ,Agriculture (General) ,S1-972 - Abstract
Globally, Soil erosion is the major land degradation problem, which impacts seriously on economic and environmental status. Geospatial techniques support and provided quantitative approach to estimate soil erosion in different conditions. In the present study, Revised Universal Soil Loss Equation (RUSLE) integrated with GIS has been used to estimate soil loss in the part of coastal Odisha system. The study area, Ganjam block have undulating topography covering 0-35% slopes. The quantitative soil loss was estimated and classified into different classes and soil erosion map was generated. The soil erosion map is classified into seven classes from very slight (80 t ha-1 yr-1). The results indicate that 90.9% (22330 ha) of the study area falls in very low erosion category, which may be due to level topography and regular vegetation cover. The other erosion classes such as moderate, high and very high erosion occurred in the range of 2.12%, 2.23% and 1.49 %, respectively. The high soil erosion risk is spatially situated in the foothills and upper steep slope of the area. The results can certainly aid in implementation of soil management and conservation practices to reduce the soil erosion in the coastal Odisha regions of Eastern India.
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- 2019
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18. Evaluation of Different Tomato (Solanum lycopersicum L.) Entries and Varieties for Performance and Adaptation in Mali, West Africa
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Wubetu Bihon, Kukom Edoh Ognakossan, Jean-Baptiste Tignegre, Peter Hanson, Kabirou Ndiaye, and Ramasamy Srinivasan
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Solanum lycopersicum ,adaptation ,growing season ,fruit quality ,Plant culture ,SB1-1110 - Abstract
Tomato is an important vegetable crop and plays a major role in the food and nutrition security of the people of Mali. Production has increased in the recent decades but improvement in the fruit yield and quality remains suboptimal. Limited access to the best-adapted tomato varieties to the local conditions, pests and diseases are the major limiting factors for improving productivity. This study evaluated the performance of different tomato entries and varieties for their productivity, resistance to pests and diseases and postharvest fruit quality in Mali. Twenty-two entries and varieties of tomato in the rainy season and twenty-four in the dry season were evaluated. Varieties that were well adapted, better yielded, disease resistant and with good fruit quality were identified. Major plant diseases observed included tomato yellow leaf curve disease (TYLCD), bacterial wilt, bacterial leaf spot, early blight and southern blight. However, TYLCD was the major problem during the dry season. The variety of Icrixina was the most affected by TYLCD in both the rainy and dry seasons, although its total yield was not affected and remained one of the highest. Konica was one of the most susceptible varieties to bacterial wilt and bacterial leaf spot diseases. Tomato accession AVTO1710 provided the highest fruit yield (40.9 t/ha), while AVTO1704 provided the lowest (6.50 t/ha) in the rainy season. In contrast the highest yield during the dry growing season was 20 t/ha from VIO43614. Tomato entries and varieties varied in their postharvest fruit quality attributes (firmness, total soluble solid, pH and dry matter). Production season clearly influenced yield, disease occurrence and severity, as well as postharvest fruit qualities. The study identified better disease-resistant and yielding tomato entries suitable for rainy and dry growing seasons, which can be considered and scaled up for production so that farmers in Mali can produce tomato all year round.
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- 2022
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19. Screening of Amaranthus sp. Varieties for Resistance to Bacterial Wilt Caused by Ralstonia solanacearum
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Rachidatou Sikirou, Marie Epiphane Dossoumou, Judith Honfoga, Victor Afari-Sefa, Ramasamy Srinivasan, Mathews Paret, and Wubetu Bihon
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bacterial wilt ,Ralstonia solanacearum ,amaranth ,screening ,resistance ,Plant culture ,SB1-1110 - Abstract
Bacterial wilt, caused by Ralstonia solanacearum, is an emerging constraint in amaranth production in Benin. Host resistance is the most sustainable disease control measure. Ten amaranth varieties including A2002, Bresil (B) -Sel, Madiira 2, AC-NL, GARE ES13-7, Madiira 1, UG-AMES13-2, AM-NKGN, IP-5-Sel and a local variety from Benin were screened for resistance to bacterial wilt. The study was conducted in a screen house and in the naturally contaminated open field during a consecutive rainy and dry season using a randomized complete block design with four and three replications, respectively. In the screen house, plants were inoculated by drenching a 40 mL of bacterial suspension containing 108 CFU/mL of R. solanacearum strain NCBI 5 GenBank N° MH397250 at the collar region. The bacterial wilt incidence (BWI) and the area under the disease progress curve (AUDPC) suggested differential reactions of amaranth varieties to the pathogen. BWI and AUDPC were low for UG-AMES13-2, moderate for Madiira 2, AM-NKGN and the local variety and very high for A2002, Bresil (B) -Sel, AC-NL, GARE ES13-7, Madiira 1 and IP-5-Sel. The World Vegetable Center’s UG-AMES13-2 can be considered as first choice, which is resistant to R. solanacearum, and should be scaled up for seed production towards supporting farmers.
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- 2021
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20. Occurrence of the South American Tomato Leaf Miner, Tuta absoluta (Meyrick) in Southern Shan, Myanmar
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Sopana Yule, Ni Ni Htain, Aung Kyaw Oo, Paola Sotelo-Cardona, and Ramasamy Srinivasan
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Tuta absoluta ,Inle Lake ,land cultivation ,floating tomato cultivation ,Southeast Asia ,Science - Abstract
The South American tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), one of the most important invasive insect pests affecting tomato production worldwide, was for the first time detected in Myanmar. Preliminary surveys on pest occurrence on tomato crops in Myanmar suggested the presence of T. absoluta in Southern Shan State, but there was no official survey conducted until the end of 2019. Therefore, this study aimed to confirm the presence of T. absoluta in Myanmar. The presence of T. absoluta was specifically observed in the Southern Shan State, which is the largest tomato production area in Myanmar, where tomato is grown under two cultivation methods, floating and land cultivation. The highest T. absoluta infestation was recordedat Kalaw with (82%), followed by Inle Lake (i.e., floating cultivation) (20%) and Pin Ta Ya (10%). The amount of T. absoluta larvae was significantly higher in the lower third of the plants, followed by the middle section and upper section, respectively, in three fields surveyed. Potential and severe economic damage may be expected if management practices are not in place to reduce the presence of this invasive pest. It is of immediate importance that plant protection and quarantine offices of ASEAN member states coordinate their response to T. absoluta and build their capacity to monitor the pest and develop a strategy for when it arrives. In addition, a suitable management strategy is needed to reduce the occurrence of this invasive pest.
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- 2021
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21. Screening cultivated eggplant and wild relatives for resistance to sweetpotato whitefly (Bemisia tabaci) and to two-spotted spider mite (Tetranychus urticae)
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Taher, Dalia, Ramasamy, Srinivasan, Prohens, Jaime, and Rakha, Mohamed
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- 2020
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22. Evaluation of Bio-Pesticides against the South American Tomato Leaf Miner, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) in India
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Priyakshi Buragohain, Dilip Kumar Saikia, Paola Sotelo-Cardona, and Ramasamy Srinivasan
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azadirachtin ,Bacillus thuringiensis ,Beauveria bassiana ,bioassay ,bio-pesticides ,Plant culture ,SB1-1110 - Abstract
Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most economically important pests of tomato worldwide. Despite its global importance, the management of this oligophagous pest has still been a challenging task, due to its high capability to develop resistance against synthetic insecticides. Given the limited studies on the effectiveness of different bio-pesticides in India, the objective of this research was to determine the pathogenicity of different commercial formulations of Beauveria bassiana, Bacillus thuringiensis, and neem (Azadirachtin), against T. absoluta, under laboratory and field conditions. For the Bacillus thuringiensis formulations, Green Larvicide® and Delfin® recorded an LC50 of 4.10 × 10⁹ CFU/mL and 8.06 × 106 spores/mg, respectively, while for the B. bassiana formulations, Green Beauveria® and BB Power® were 4.473 × 107 spores/mL and 1.367 × 107 CFU/g, respectively. Furthermore, the results showed high susceptibility to both the commercial neem formulations with Ecotin®, recording an LC50 of 91.866 ppm, and Econeem Plus® recording 212.676 ppm. The results from the field conditions at different locations of Andhra Pradesh, India, showed significant differences (p < 0.001) for leaf and fruit infestation among the interaction effect of treatments and locations. Bio-pesticides, especially neem and B. thuringiensis formulations, reduced T. absoluta infestation similarly to the chemical treatment, without affecting the yield. Therefore, bio-pesticides can be considered as safe alternatives to synthetic pesticides, for the management of T. absoluta.
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- 2021
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23. Proteo-Trancriptomic Analyses Reveal a Large Expansion of Metalloprotease-Like Proteins in Atypical Venom Vesicles of the Wasp Meteorus pulchricornis (Braconidae)
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Jean-Luc Gatti, Maya Belghazi, Fabrice Legeai, Marc Ravallec, Marie Frayssinet, Stéphanie Robin, Djibril Aboubakar-Souna, Ramasamy Srinivasan, Manuele Tamò, Marylène Poirié, and Anne-Nathalie Volkoff
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Meteorus pulchricornis ,parasitoid wasp ,Braconidae ,venomics ,virus-like particles (VLPs) ,proteomic ,Medicine - Abstract
Meteorus pulchricornis (Ichneumonoidea, Braconidae) is an endoparasitoid wasp of lepidopteran caterpillars. Its parasitic success relies on vesicles (named M. pulchricornis Virus-Like Particles or MpVLPs) that are synthesized in the venom gland and injected into the parasitoid host along with the venom during oviposition. In order to define the content and understand the biogenesis of these atypical vesicles, we performed a transcriptome analysis of the venom gland and a proteomic analysis of the venom and purified MpVLPs. About half of the MpVLPs and soluble venom proteins identified were unknown and no similarity with any known viral sequence was found. However, MpVLPs contained a large number of proteins labelled as metalloproteinases while the most abundant protein family in the soluble venom was that of proteins containing the Domain of Unknown Function DUF-4803. The high number of these proteins identified suggests that a large expansion of these two protein families occurred in M. pulchricornis. Therefore, although the exact mechanism of MpVLPs formation remains to be elucidated, these vesicles appear to be “metalloproteinase bombs” that may have several physiological roles in the host including modifying the functions of its immune cells. The role of DUF4803 proteins, also present in the venom of other braconids, remains to be clarified.
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- 2021
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24. Elucidating the Fitness of a Dead-End Trap Crop Strategy against the Tomato Fruitworm, Helicoverpa armigera
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Purushottam Gyawali, Shaw-Yhi Hwang, Paola Sotelo-Cardona, and Ramasamy Srinivasan
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Solanum lycopersicum ,tomato fruitworm ,cotton bollworm ,oviposition ,Solanum viarum ,dead-end trap crop ,Science - Abstract
Solanum viarum has been proposed as a potential dead-end trap crop for the management of Helicoverpa armigera because of its unsuitability for larval growth and survival despite being overwhelmingly preferred for oviposition. This study delved into the different S. viarum accessions for ovipositional preference and non-suitability for larval growth and survival of H. armigera. Besides, foliage trichomes, acylsugars, and phenolic content of S. viarum plants were assessed and compared with tomato. Since there is no significant variation in the ovipositional preference and larval performance of H. armigera, our result revealed that all those evaluated accessions of S. viarum have the potential to be used as a dead-end trap crop for the management of H. armigera. However, significant variation among the S. viarum accessions in terms of H. armigera oviposition was also evident in a no-choice experiment. Because of high-density glandular trichomes, acylsugars, and phenolic content, S. viarum significantly impaired H. armigera larval growth and survival compared to the tomato. Hence, our study elucidated that the S. viarum plant fits with the criteria for dead-end trap crop, and has the potential as a dead-end trap crop for the H. armigera, which needs to be tested under large, open-field conditions.
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- 2021
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25. Genome, host genome integration, and gene expression in Diadegma fenestrale ichnovirus from the perspective of coevolutionary hosts
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Kim, Juil, primary, Rahman, Md-Mafizur, additional, Kim, A-Young, additional, Ramasamy, Srinivasan, additional, Kwon, Min, additional, and Kim, Yonggyun, additional
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- 2023
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26. Novel family of terpene synthases evolved from trans -isoprenyl diphosphate synthases in a flea beetle
- Author
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Beran, Franziska, Rahfeld, Peter, Luck, Katrin, Nagel, Raimund, Vogel, Heiko, Wielsch, Natalie, Irmisch, Sandra, Ramasamy, Srinivasan, Gershenzon, Jonathan, Heckel, David G., and Köllner, Tobias G.
- Published
- 2016
27. Agrobacterium rhizogenes influences aervine enhancement in hairy root culture of Aerva javanica (Burm.f.) Juss. ex Schult and in silico assessment of human breast cancer activity
- Author
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Ramasamy Srinivasan, Kamalanathan D, Selvakumar Boobalan, Venkatachalam Saranyaa, Sekar Mouliganesh, and Renganathan Seenivasagan
- Subjects
Plant Science ,Agronomy and Crop Science ,General Biochemistry, Genetics and Molecular Biology ,Food Science ,Biotechnology - Published
- 2023
28. Evaluation of Different Bacterial Wilt Resistant Eggplant Rootstocks for Grafting Tomato
- Author
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Ravishankar Manickam, Jaw-Rong Chen, Paola Sotelo-Cardona, Lawrence Kenyon, and Ramasamy Srinivasan
- Subjects
Ralstonia ,Solanum lycopersicum ,Solanum melongena ,grafting-compatibility ,fruit ,Botany ,QK1-989 - Abstract
Bacterial wilt (BW) is one of the most economically important diseases of tomato and eggplant in the tropics and subtropics, and grafting onto resistant rootstocks can provide an alternative and effective solution to manage soil-borne bacterial in these crops. This study was conducted to evaluate the BW resistance and agronomic potential of newly identified eggplant accessions as rootstocks for tomato grafting. Five BW resistant eggplant accessions (VI041809A, VI041943, VI041945, VI041979A, and VI041984) from the World Vegetable Center were evaluated as rootstocks for grafting with two different fresh market tomato cultivars (Victoria and TStarE) as scion under open field conditions in Taiwan. Graft compatibility using the tube grafting method as well as BW wilting percentage, disease index, fruit yield and quality parameters were assessed. All the rootstocks showed good graft compatibility (93% and above) and grafted plants showed low wilting percentage (0.0–20.0%) and disease index (0.0–20.8%) following inoculation with BW. Yield for the eggplant rootstock grafted tomato plants was higher compared to the non-grafted tomatoes and self-grafted tomato. Fruit quality was not affected by grafting, although some differences in antioxidant activities were observed. The new eggplant rootstocks can be considered as alternatives to the rootstocks currently used for commercial production of tomatoes during the hot-wet season.
- Published
- 2021
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29. Evaluation of wild tomato accessions (Solanum spp.) for resistance to two-spotted spider mite (Tetranychus urticae Koch) based on trichome type and acylsugar content
- Author
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Rakha, Mohamed, Bouba, Ndeye, Ramasamy, Srinivasan, Regnard, Jean-Luc, and Hanson, Peter
- Published
- 2017
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30. Identification of resistance to Bemisia tabaci Genn. in closely related wild relatives of cultivated tomato based on trichome type analysis and choice and no-choice assays
- Author
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Rakha, Mohamed, Hanson, Peter, and Ramasamy, Srinivasan
- Published
- 2017
- Full Text
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31. Effect of Pheromone-Mediated Mating Disruption on Pest Population Density of Maruca vitrata (Fabricius) (Crambidae: Lepidoptera)
- Author
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Onkarappa Dhanyakumar, Ramasamy Srinivasan, Muthugounder Mohan, Thiruvengadam Venkatesan, Kamanur Murali Mohan, Narayanappa Nagesha, and Paola Sotelo-Cardona
- Subjects
mating disruption ,integrated pest management ,pheromone blend ,legume pod borer ,mungbean ,Science - Abstract
The legume pod borer (Maruca vitrata) is one of the most serious legume pests due to its wide host range and high damage potential. Pheromone components on M. vitrata have been previously identified, allowing research on more environmentally friendly IPM tools for its control. M. vitrata produces a three-component pheromone blend containing (E, E)-10,12-hexadecadienal (major), (E, E)-10,12-hexadecadienol (minor), (E)-10-hexadecenal (minor). This study focused on the efficacy of synthetic pheromone lures and their blend components for mating disruption in M. vitrata. Under laboratory conditions, the mating behavior of M. vitrata pairs was observed from 18:00 to 02:00 h in an interval of 20 min to assess the efficacy of different pheromone lures. The scotophase behavior results show that the complete pheromone blend (E, E)-10,12-hexadecadienal + (E, E)-10,12-hexadecadienol + (E)-10-hexadecenal with a blend ratio of 1:1:1 effectively disrupted mating. The impact on mating disruption was evident from the lower fecundity and egg hatch/eclosion. The same lures were evaluated in a small-scale caged field study. The results show that the pheromone blend of (E, E)-10,12-hexadecadienal + (E, E)-10,12-hexadecadienol + (E)-10-hexadecenal in a1:1:1 ratio significantly disrupted the normal mating, leading to lower flower and pod damage and higher mung bean yield.
- Published
- 2020
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32. Exploring the Mechanisms of the Spatiotemporal Invasion of Tuta absoluta in Asia
- Author
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Ritter A. Guimapi, Ramasamy Srinivasan, Henri E. Tonnang, Paola Sotelo-Cardona, and Samira A. Mohamed
- Subjects
cellular automata ,Tuta absoluta ,insect’s pest invasion ,dispersal pattern ,international crop trade ,integrated pest management ,Agriculture (General) ,S1-972 - Abstract
International crop exchange always brings the risk of introducing pests to countries where they are not yet present. The invasive pest Tuta absoluta (Meyrick 1917), after taking just a decade (2008–2017) to invade the entire Africa continent, is now continuing its expansion in Asia. From its first detection in Turkey (2009), the pest has extended its range of invasion at a very high speed of progression to the southeast part of Asia. This study adopted the cellular automata modelling method used to successfully predict the spatiotemporal invasion of T. absoluta in Africa to find out if the invasive pest is propagating with a similar pattern of spread in Asia. Using land cover vegetation, temperature, relative humidity and the natural flight ability of Tuta absoluta, we simulated the spread pattern considering Turkey as the initial point in Asia. The model revealed that it would take about 20 years for the pest to reach the southeast part of Asia, unlike real life where it took just about 10 years (2009–2018). This can be explained by international crop trade, especially in tomatoes, and movement of people, suggesting that recommendations and advice from the previous invasion in Europe and Africa were not implemented or not seriously taken into account. Moreover, some countries like Taiwan and the Philippines with suitable environmental condition for the establishment of T. absoluta are not at risk of natural invasion by flight, but quarantine measure must be put in place to avoid invasion by crop transportation or people movement. The results can assist policy makers to better understand the different mechanisms of invasion of T. absoluta in Asia, and therefore adjust or adapt control measures that fit well with the dynamic of the invasive pest observed.
- Published
- 2020
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33. Insecticide resistance status in Culex quinquefasciatus in Benin
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Agnes Yadouléton, Kefilath Badirou, Ramziath Agbanrin, Hanna Jöst, Roseline Attolou, Ramasamy Srinivasan, Gil Padonou, and Martin Akogbéto
- Subjects
Culex quinquefasciatus ,Insecticide ,Resistance ,Agriculture ,Benin ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Culex quinquefasciatus, an arboviral and filarial vector, is present year round in several cities of the Republic of Benin. There is more information on the resistance status to malaria vectors compared to Culicines. It is therefore unfortunate that the international focus is on Anopheles control and not so much done against Cx. quinquefasciatus, a rather more resilient mosquito to many insecticides that deserves attention. The present study aims to assess the resistance status of Cx. quinquefasciatus to carbamates, pyrethroids and organochlorine and discuss the implications for vector control in four contrasting localities of the country. Methods Four contrasting localities of the country were selected for mosquito collection during the dry season based on their variation in agricultural production, use of insecticides and/or ecological settings. Bioassay were performed on adults collected from the field to assess the susceptibility of Cx. quinquefasciatus to insecticide-impregnated papers (permethrin 0.75%, delthamethrin 0.05%, DDT 4%, and bendiocarb 0.1%) following WHOPES guidelines. Molecular assays were carried out to detect the presence of knock down resistance (kdr) and acetylcholinesterase (ace. 1) mutations in surviving specimens using PCR techniques. Results WHO diagnostic tests showed high frequency of resistance in Cx. quinquefasciatus to permethrin (ranging from 4 to 24% mortality), deltamethrin (24 to 48%), DDT (4 to 12%) and bendiocarb (60 to 76%) in the four selected areas. This was consistent with the presence of target site insensitivity due to kdr and ace.1 mutations, which were significantly higher in areas where farmers used insecticides for pests control than in areas where no insecticides were used (p < 0.05.). Conclusion These findings showed that wild populations of Cx. quinquefasciatus have developed resistance against pyrethroids, organochlorine and carbamate. This situation of resistance may seriously jeopardize the efficacy of Insecticide Residual Spray (IRS) and Long-Lasting Insecticide nets (LLINs) on which, most African countries including Benin, rely to reduce malaria transmission.
- Published
- 2015
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34. Phyllotreta striolata flea beetles use host plant defense compounds to create their own glucosinolate-myrosinase system
- Author
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Beran, Franziska, Pauchet, Yannick, Kunert, Grit, Reichelt, Michael, Wielsch, Natalie, Vogel, Heiko, Reinecke, Andreas, Svatoš, Aleš, Mewis, Inga, Schmid, Daniela, Ramasamy, Srinivasan, Ulrichs, Christian, Hansson, Bill S., Gershenzon, Jonathan, and Heckel, David G.
- Published
- 2014
35. Mechanism of Resistance in Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] to bruchids, Callosobruchus spp. (Coleoptera: Bruchidae)
- Author
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Abdul R. War, Surya Murugesan, Venkata N. Boddepalli, Ramasamy Srinivasan, and Ramakrishnan M. Nair
- Subjects
mungbean ,bruchids ,biotic stress ,breeding constraints ,resistance ,Plant culture ,SB1-1110 - Abstract
Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important pulse crop in Asia, and is consumed as dry seeds and as bean sprouts. It is an excellent source of digestible protein. Bruchids [Callosobruchus chinensis (L.) and Callosobruchus maculatus (F.)] are the important pests of mungbean and cause damage in the field and in storage. Bruchid infestation reduces the nutritional and market value of the grain and renders seeds unfit for human consumption, agricultural and commercial uses. These pests are controlled mainly by fumigation with highly toxic chemicals such as carbon disulfide, phosphene, and methyl bromide, or by dusting with several other insecticides, which leave residues on the grain, thus, threatening food safety. Some plant-based extracts have been found useful in controlling bruchids, but are not fully successful due to their short-term activity, rapid degradability, and potentially negative effect on seed germination. Although some wild sources of bruchid resistance in mungbean have been reported, which have been used to develop bruchid- resistant lines, undesirable genetic linkages threaten the proper exploitation of genetic diversity from wild germplasm into commercial cultivars. Further, biotype variation in bruchids has rendered some mungbean lines susceptible that otherwise would have been resistant to the pest. Host plant resistance is a cost-effective and a safe alternative to control bruchids in mungbean and is associated with morphological, biochemical, and molecular traits. These traits affect insect growth and development, thereby, reduce the yield losses by the pests. Understanding the defense mechanisms against insect pests could be utilized in exploiting these traits in crop breeding. This review discusses different traits in mungbean involved in defense against bruchids and their utility in pest management. We also highlight the breeding constraints for developing bruchid-resistant mungbean and how can these constraints be minimized. We further highlight the importance of supporting conventional breeding techniques by molecular techniques such as molecular markers linked to bruchid resistance.
- Published
- 2017
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36. Identification of Two Diamondback Moth Parasitoids, Diadegma fenestrale and Diadegma semiclausum, Using LAMP for Application in Biological Control
- Author
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Nam, Hwayeun, primary, Kwon, Min, additional, Ramasamy, Srinivasan, additional, and Kim, Juil, additional
- Published
- 2022
- Full Text
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37. Knowledge, attitude and practice of tomato retailers towards hygiene and food safety in Harar and Dire Dawa, Ethiopia
- Author
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Biruk Alemu Gemeda, Kebede Amenu, Sisay Girma, Delia Grace, Ramasamy Srinivasan, Ralph Roothaert, and Theodore J.D. Knight-Jones
- Subjects
Food Science ,Biotechnology - Published
- 2023
38. Can phone text messages promote the use of integrated pest management? A study of vegetable farmers in Cambodia
- Author
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Mercy Mwambi, Lutz Depenbusch, Uon Bonnarith, Paola Sotelo-Cardona, Khemrin Kieu, Nicolas di Tada, Ramasamy Srinivasan, and Pepijn Schreinemachers
- Subjects
Economics and Econometrics ,General Environmental Science - Published
- 2023
39. The continued effects of COVID-19 on the lives and livelihoods of vegetable farmers in India
- Author
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Sandhya S. Kumar, Pepijn Schreinemachers, Arshad Ahmad Pal, Ravishankar Manickam, Ramakrishnan M. Nair, Ramasamy Srinivasan, and Jody Harris
- Subjects
Multidisciplinary ,Farmers ,Vegetables ,Communicable Disease Control ,Humans ,India ,COVID-19 ,Food Supply - Abstract
India experienced a rapid rise in COVID-19 infections from March 2021. States imposed varying levels of lockdowns and curfews to curb the spread of the disease. These restrictions severely affected the functioning of food systems. The objective of this study was to analyze how COVID-19 continues to affect agricultural production, food security and household diets of vegetable farmers. A phone-based survey was conducted with 595 vegetable farmers in the states of Andhra Pradesh, Assam, Jharkhand, Karnataka and Odisha, 60% of whom had been interviewed a year earlier. Overall, 60% of farmers experienced decreased vegetable production; over 80% reported a reduction in consumption of at least one food group; and 45% reported some level of food insecurity between May 2020 and May 2021. Farmers who reported decreased staples production, difficulty accessing seeds/seedlings, or reduced their household spending were more likely to report decreased vegetable production. Vegetable consumption was positively associated with receipt of COVID-19 relief benefits, borrowing money, or having home gardens. Farmers who received public agricultural assistance, or had reduced expenses, were more likely to have lower vegetable consumption. Greater severity of food insecurity was associated with farmers belonging to underprivileged social groups, non-Hindus, or those who experienced decrease in livestock production, weather related disruptions or received COVID-19 assistance. This is one of few studies that have conducted a longitudinal assessment of the impacts across multiple waves of COVID-19. COVID-19 is seen to be one among several shocks experienced by farm households, and exacerbated existing issues within agriculture and food security. There is a need for public policy support to strengthen both production and consumption of vegetables.
- Published
- 2022
40. Genome, host genome integration, and gene expression in Diadegma fenestrale ichnovirus from the perspective of coevolutionary hosts.
- Author
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Juil Kim, Rahman, Md-Mafizur, A-Young Kim, Ramasamy, Srinivasan, Min Kwon, and Yonggyun Kim
- Subjects
GENE expression ,GENOME size ,GENE families ,CIRCULAR DNA ,DIAMONDBACK moth ,GENOMES ,NUCLEOTIDE sequencing - Abstract
Polydnaviruses (PDVs) exhibit species-specific mutualistic relationships with endoparasitoid wasps. PDVs can be categorized into bracoviruses and ichnoviruses, which have independent evolutionary origins. In our previous study, we identified an ichnovirus of the endoparasitoid Diadegma fenestrale and named it DfIV. Here, DfIV virions from the ovarian calyx of gravid female wasps were characterized. DfIV virion particles were ellipsoidal (246.5 nm × 109.0 nm) with a double-layered envelope. Next-generation sequencing of the DfIV genome revealed 62 nonoverlapping circular DNA segments (A1-A5, B1-B9, C1-C15, D1-D23, E1-E7, and F1-F3); the aggregate genome size was approximately 240 kb, and the GC content (43%) was similar to that of other IVs (41%-43%). A total of 123 open reading frames were predicted and included typical IV gene families such as repeat element protein (41 members), cysteine motif (10 members), vankyrin (9 members), polar residue-rich protein (7 members), vinnexin (6 members), and N gene (3 members). Neuromodulin N (2 members) was found to be unique to DfIV, along with 45 hypothetical genes. Among the 62 segments, 54 showed high (76%-98%) sequence similarities to the genome of Diadegma semiclausum ichnovirus (DsIV). Three segments, namely, D22, E3, and F2, contained lepidopteran host genome integration motifs with homologous regions of about 36-46 bp between them (Diadegma fenestrale ichnovirus, DfIV and lepidopteran host, Plutella xylostella). Most of the DfIV genes were expressed in the hymenopteran host and some in the lepidopteran host (P. xylostella), parasitized by D. fenestrale. Five segments (A4, C3, C15, D5, and E4) were differentially expressed at different developmental stages of the parasitized P. xylostella, and two segments (C15 and D14) were highly expressed in the ovaries of D. fenestrale. Comparative analysis between DfIV and DsIV revealed that the genomes differed in the number of segments, composition of sequences, and internal sequence homologies. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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41. Mapping and identification of potential target genes from short–RNA seq for the control of Pieris rapae larvae
- Author
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P. Malini, Rajendran Senthil Kumar, Ramasamy Srinivasan, and Mat Ali Rawdzah
- Subjects
Male ,0106 biological sciences ,Sequence assembly ,Genes, Insect ,Pieris rapae ,RNA-Seq ,Single-nucleotide polymorphism ,Computational biology ,01 natural sciences ,Genome ,Transcriptome ,03 medical and health sciences ,Genetics ,Animals ,Gene Regulatory Networks ,Sex Attractants ,Indel ,Gene ,030304 developmental biology ,0303 health sciences ,biology ,Gene Expression Regulation, Developmental ,biology.organism_classification ,Lepidoptera ,Larva ,RNA, Small Untranslated ,Female ,010606 plant biology & botany - Abstract
Pieris rapae is a serious pest of brassicas worldwide. We performed de novo assembly of P. rapae transcriptome by next-generation sequencing and assembled approximately 65,727,422 clean paired-end reads into 32,118 unigenes, of which 13,585 were mapped to 255 pathways in the KEGG database. A total of 6173 novel transcripts were identified from reads directly mapped to P. rapae genome. Additionally, 1490 SSRs, 301,377 SNPs, and 29,284 InDels were identified as potential molecular markers to explore polymorphism within P. rapae populations. We screened and mapped 36 transcripts related to OBP, CSP, SNMP, PBAN, and OR. We analyzed the expression profiles of 7 selected genes involved in pheromone transport and degradation by quantitative real-time PCR; these genes are sex-specific and differentially expressed in the developmental stages. Overall, the comprehensive transcriptome resources described in this study could help understand and identify molecular targets particularly reproduction-related genes for developing effective P. rapae management tools.
- Published
- 2020
42. Report on the Annual Meeting of the Working Group "Phytomedicine in the Tropics and Subtropics" 2009
- Author
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Niere, Björn, Frosch, Monica, Mithöfer, Klaus, Ongamo, George Otieno, Leru, Bruno, Mbuthia, Lilian Wanjiru, von Alten, Henning, Grunewaldt-Stöcker, Gisela, Anyusheva, Maria, La, Nguyen, Lamers, Marc, Streck, Thilo, Bekele, Nigat, Mithöfer, Dagmar, Amudavi, David, Obare, Gideon, Bahar, Habibullah, Stanley, John, Gregg, Peter, del Socorro, Alice, Sultan, Muna, Dehne, Heinz-Wilhelm, Steiner, Ulrike, Bhandari, Bishnu Kumari, Coll, Moshe, Baklawa, Mohamed, Massoud, Samia, El-Kady, Gamal, Ramasamy, Srinivasan, Su, Fu-Cheng, Huang, Chun-Chu, Lin, Mei-ying, Hsu, Yun-che, Hillnhütter, Christian, Dubois, Thomas, Coyne, Danny, Nsubuga, Erostus, Sikora, Richard A., Macharia, Ibrahim Ndegwa, Waibel, Hermann, Dahal, Diwakar, Pich, Andreas, Wydra, Kerstin, Beran, Franziska, Büttner, Carmen, Mewis, Inga, Ulrichs, Christian, Endah, Ndambi Beninweck, Cadisch, Georg, Elzein, Abulegasim, Heller, Annerose, Mühlbach, Hans-Peter, Tantau, Hanny, Vogel, Stephanie, Renk, Steffi, Schultz, Dorothee, Hoque, M. Imdadul, Sarker, Rakha Hari, Schulze, Jana, Khan, Salim, Abbo, Azza Siddig Hussien, Idris, Mohamed Osman, Elballa, Mustafa M. A., Caceres, Hilda Luz Lezcano, Gerold, Gerhard, Eisa, Maymoona Ahmed, Roth, Mechthild, Gebreiyesus, Ameha Y., and Debener, Thomas
- Published
- 2010
43. Progeny fitness determines the performance of the parasitoid Therophilus javanus, a prospective biocontrol agent against the legume pod borer
- Author
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Barry R. Pittendrigh, Ramasamy Srinivasan, Manuele Tamò, Aimé H. Bokonon-Ganta, Djibril Aboubakar Souna, Mesmin Alizannon, Anne-Nathalie Volkoff, Marc Ravallec, International Institute of Tropical Agriculture [Nigeria] (IITA), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), Université d’Abomey-Calavi (UAC), Diversité, Génomes & Interactions Microorganismes - Insectes [Montpellier] (DGIMI), Université de Montpellier (UM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), World Vegetable Center, Michigan State University [East Lansing], Michigan State University System, International Institute of Tropical Agriculture (IITA-Benin), Consultative Group on International Agricultural Research [CGIAR] (CGIAR)-Consultative Group on International Agricultural Research [CGIAR] (CGIAR), Cooperation and Cultural Action Service (SCAC) of the French Embassy in Cotonou N 898392E, CGIAR, and Bill & Melinda Gates Foundation OPP1082463
- Subjects
Male ,0106 biological sciences ,Behavioural ecology ,Ecophysiology ,Science ,[SDV]Life Sciences [q-bio] ,Wasps ,Biological pest control ,Moths ,010603 evolutionary biology ,01 natural sciences ,Article ,Parasitoid ,Toxicology ,Animals ,Population dynamics ,Pest Control, Biological ,Larva ,Multidisciplinary ,biology ,Host (biology) ,Reproduction ,fungi ,biology.organism_classification ,010602 entomology ,Maruca vitrata ,Medicine ,Instar ,Female ,Agroecology ,Sex ratio - Abstract
Therophilus javanus (Bhat & Gupta) is an exotic larval endoparasitoid newly imported from Asia into Africa as a classical biological control agent against the pod borer Maruca vitrata (Fabricius). The parasitoid preference for the five larval instars of M. vitrata and their influence on progeny sex ratio were assessed together with the impact of larval host age at the time of oviposition on development time, mother longevity and offspring production. In a choice situation, female parasitoids preferred to oviposit in the first three larval instars. The development of immature stages of the parasitoid was observed inside three-day-old hosts, whereby the first two larval instars of T. javanus completed their development as endoparasites and the third larval instar as ectoparasite. The development time was faster when first larval instars (two- and three-day-old) of the host caterpillars were parasitized compared to second larval instar (four-day-old). The highest proportion of daughters (0.51) was observed when females were provided with four-day-old hosts. The lowest intrinsic rate of increase (r) (0.21 ± 0.01), the lowest rate of increase (λ) (1.23 ± 0.01), and the lowest net reproductive rate (Ro) (35.93 ± 6.51) were recorded on four-day-old hosts. These results are discussed in the light of optimizing mass rearing and release strategies.
- Published
- 2021
44. Evaluating the Potential of Protected Cultivation for Off-Season Leafy Vegetable Production: Prospects for Crop Productivity and Nutritional Improvement
- Author
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Ramasamy, Srinivasan, primary, Lin, Mei-Ying, additional, Wu, Wan-Jen, additional, Wang, Hsin-I, additional, and Sotelo-Cardona, Paola, additional
- Published
- 2021
- Full Text
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45. Growing Tomato under Protected Cultivation Conditions: Overall Effects on Productivity, Nutritional Yield, and Pest Incidences
- Author
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Mei-ying Lin, Ramasamy Srinivasan, and Paola Sotelo-Cardona
- Subjects
Abiotic component ,fungi ,food and beverages ,protected cultivation ,General Medicine ,Biology ,lycopene ,Lycopene ,Horticulture ,chemistry.chemical_compound ,Colored ,chemistry ,Productivity (ecology) ,Protected cultivation ,Yield (wine) ,light spectral modification ,Relative humidity ,PEST analysis ,tomatoes - Abstract
Tomato continues to be one of the most important crops worldwide, and protected cultivation is practiced to overcome the biotic and abiotic stresses to which the plant are exposed during growth. In this study we evaluated the effect of colored net houses on the growth, yield and nutritional values, as well as the incidence of common pests under three different light conditions: (1) colored (magenta), (2) conventional (white), and open field conditions. A colored net house led the plants to grow taller with higher lycopene content, but recorded a higher number of whiteflies, compared to the conventional net house and open field conditions. Furthermore, plants under protected structures recorded lower SPAD values, but larger terminal leaflets, lower damage by leaf miners, but more damage caused by spider mites compared to those plants grown under open field conditions. Overall, we found that the use of colored net houses provided a positive effect on tomato production in terms of improvement in morphometric parameters, however, to obtain higher yields under this production system, it is important to reduce the elevated temperature and increase the relative humidity inside the protective structures to be adapted for local growing conditions in Taiwan.
- Published
- 2021
- Full Text
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46. Evaluation of Bio-Pesticides against the South American Tomato Leaf Miner, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) in India
- Author
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Paola Sotelo-Cardona, Ramasamy Srinivasan, D. K. Saikia, and Priyakshi Buragohain
- Subjects
biology ,fungi ,Beauveria bassiana ,Plant culture ,Plant Science ,Bassiana ,Horticulture ,biology.organism_classification ,medicine.disease_cause ,Gelechiidae ,SB1-1110 ,Toxicology ,chemistry.chemical_compound ,Azadirachtin ,chemistry ,bioassay ,Bacillus thuringiensis ,Infestation ,medicine ,Tuta absoluta ,PEST analysis ,bio-pesticides ,azadirachtin - Abstract
Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most economically important pests of tomato worldwide. Despite its global importance, the management of this oligophagous pest has still been a challenging task, due to its high capability to develop resistance against synthetic insecticides. Given the limited studies on the effectiveness of different bio-pesticides in India, the objective of this research was to determine the pathogenicity of different commercial formulations of Beauveria bassiana, Bacillus thuringiensis, and neem (Azadirachtin), against T. absoluta, under laboratory and field conditions. For the Bacillus thuringiensis formulations, Green Larvicide® and Delfin® recorded an LC50 of 4.10 × 10⁹ CFU/mL and 8.06 × 106 spores/mg, respectively, while for the B. bassiana formulations, Green Beauveria® and BB Power® were 4.473 × 107 spores/mL and 1.367 × 107 CFU/g, respectively. Furthermore, the results showed high susceptibility to both the commercial neem formulations with Ecotin®, recording an LC50 of 91.866 ppm, and Econeem Plus® recording 212.676 ppm. The results from the field conditions at different locations of Andhra Pradesh, India, showed significant differences (p <, 0.001) for leaf and fruit infestation among the interaction effect of treatments and locations. Bio-pesticides, especially neem and B. thuringiensis formulations, reduced T. absoluta infestation similarly to the chemical treatment, without affecting the yield. Therefore, bio-pesticides can be considered as safe alternatives to synthetic pesticides, for the management of T. absoluta.
- Published
- 2021
47. Exploring the Mechanisms of the Spatiotemporal Invasion of Tuta absoluta in Asia
- Author
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Ramasamy Srinivasan, Paola Sotelo-Cardona, Henri E. Z. Tonnang, Samira A. Mohamed, and Ritter A. Guimapi
- Subjects
0106 biological sciences ,Integrated pest management ,Tuta absoluta ,dispersal pattern ,Plant Science ,Land cover ,01 natural sciences ,law.invention ,law ,Quarantine ,lcsh:Agriculture (General) ,Initial point ,biology ,integrated pest management ,Agroforestry ,cellular automata ,biology.organism_classification ,lcsh:S1-972 ,010602 entomology ,Geography ,insect’s pest invasion ,PEST analysis ,Agronomy and Crop Science ,010606 plant biology & botany ,Food Science ,international crop trade - Abstract
International crop exchange always brings the risk of introducing pests to countries where they are not yet present. The invasive pest Tuta absoluta (Meyrick 1917), after taking just a decade (2008&ndash, 2017) to invade the entire Africa continent, is now continuing its expansion in Asia. From its first detection in Turkey (2009), the pest has extended its range of invasion at a very high speed of progression to the southeast part of Asia. This study adopted the cellular automata modelling method used to successfully predict the spatiotemporal invasion of T. absoluta in Africa to find out if the invasive pest is propagating with a similar pattern of spread in Asia. Using land cover vegetation, temperature, relative humidity and the natural flight ability of Tuta absoluta, we simulated the spread pattern considering Turkey as the initial point in Asia. The model revealed that it would take about 20 years for the pest to reach the southeast part of Asia, unlike real life where it took just about 10 years (2009&ndash, 2018). This can be explained by international crop trade, especially in tomatoes, and movement of people, suggesting that recommendations and advice from the previous invasion in Europe and Africa were not implemented or not seriously taken into account. Moreover, some countries like Taiwan and the Philippines with suitable environmental condition for the establishment of T. absoluta are not at risk of natural invasion by flight, but quarantine measure must be put in place to avoid invasion by crop transportation or people movement. The results can assist policy makers to better understand the different mechanisms of invasion of T. absoluta in Asia, and therefore adjust or adapt control measures that fit well with the dynamic of the invasive pest observed.
- Published
- 2020
48. Temperature-Dependent Growth and Virulence, and Mass Production Potential of Two Candidate Isolates ofMetarhizium anisopliae(Metschnikoff) Sorokin for ManagingMaruca vitrataFabricius (Lepidoptera: Crambidae) on Cowpea
- Author
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V. Tumuhaise, Paul N. Ndegwa, Sunday Ekesi, N.K. Maniania, Chrysantus M. Tanga, Henri E. Z. Tonnang, Samira A. Mohamed, Lucy W. Irungu, and Ramasamy Srinivasan
- Subjects
0106 biological sciences ,0301 basic medicine ,Larva ,biology ,Biological pest control ,Metarhizium anisopliae ,biology.organism_classification ,01 natural sciences ,Conidium ,Lepidoptera genitalia ,010602 entomology ,03 medical and health sciences ,Horticulture ,030104 developmental biology ,Crambidae ,Maruca vitrata ,Germination ,Insect Science ,Agronomy and Crop Science ,Ecology, Evolution, Behavior and Systematics - Abstract
Entomopathogenic fungi are increasingly gaining recognition as a viable alternative to synthetic insecticides for pest management; their efficacy is influenced by several biotic and abiotic factors. In this study, the effect of temperature on germination, growth and virulence of two isolates of Metarhizium anisopliae, ICIPE 18 and ICIPE 69, against first-instar larvae of Maruca vitrata at temperatures ranging from 15–35 °C, and mass-production potential of the isolates were assessed under laboratory conditions. Minimum, optimum and maximum threshold temperatures for efficacy of the best performing isolate, ICIPE 69, were estimated by the quadratic equation which emerged as the best model among the nonlinear mathematical expressions tested. Neither isolate germinated at 15 °C while germination was low at 35 °C for both. The optimum temperature for germination, radial growth and virulence of ICIPE 69 and ICIPE 18 ranged between 25–30 °C and 25–33 °C, respectively. Mortality of M. vitrata by both isolates ranged between 56.0 and 91.6�ross the different temperatures, with the highest mortality occurring at 25 and 30 °C for ICIPE 69 and ICIPE 18, respectively. The shortest LT50 values were 2.5 days for ICIPE 18 and 2.2 days for ICIPE 69 at 33 °C and 25 °C, respectively. The quadratic model predicted 25–30 °C as the optimum temperature range for maximum efficacy of M. anisopliae isolate ICIPE 69 against M. vitrata. Upper and lower threshold temperatures were predicted as 40 °C and 10 °C, respectively. Comparison of aerial conidia production on rice showed that ICIPE 69 yielded higher amounts of conidia (18.4 g conidia/kg rice) than ICIPE 18 (12.4 g conidia/kg rice). The results suggest that ICIPE 69 is a promising candidate for biocontrol of M. vitrata.
- Published
- 2018
49. Screening of Amaranthus sp. Varieties for Resistance to Bacterial Wilt Caused by Ralstonia solanacearum
- Author
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Ramasamy Srinivasan, M.E.E.A. Dossoumou, Rachidatou Sikirou, Mathews L. Paret, Victor Afari-Sefa, Wubetu Bihon, and Judith Honfoga
- Subjects
Ralstonia solanacearum ,Host resistance ,amaranth ,Inoculation ,screening ,Bacterial wilt ,Randomized block design ,Plant culture ,Amaranth ,Plant Science ,Horticulture ,Biology ,biology.organism_classification ,SB1-1110 ,bacterial wilt ,resistance ,chemistry.chemical_compound ,chemistry ,Dry season ,Pathogen - Abstract
Bacterial wilt, caused by Ralstonia solanacearum, is an emerging constraint in amaranth production in Benin. Host resistance is the most sustainable disease control measure. Ten amaranth varieties including A2002, Bresil (B) -Sel, Madiira 2, AC-NL, GARE ES13-7, Madiira 1, UG-AMES13-2, AM-NKGN, IP-5-Sel and a local variety from Benin were screened for resistance to bacterial wilt. The study was conducted in a screen house and in the naturally contaminated open field during a consecutive rainy and dry season using a randomized complete block design with four and three replications, respectively. In the screen house, plants were inoculated by drenching a 40 mL of bacterial suspension containing 108 CFU/mL of R. solanacearum strain NCBI 5 GenBank N° MH397250 at the collar region. The bacterial wilt incidence (BWI) and the area under the disease progress curve (AUDPC) suggested differential reactions of amaranth varieties to the pathogen. BWI and AUDPC were low for UG-AMES13-2, moderate for Madiira 2, AM-NKGN and the local variety and very high for A2002, Bresil (B) -Sel, AC-NL, GARE ES13-7, Madiira 1 and IP-5-Sel. The World Vegetable Center’s UG-AMES13-2 can be considered as first choice, which is resistant to R. solanacearum, and should be scaled up for seed production towards supporting farmers.
- Published
- 2021
50. Transcriptome sequencing, and rapid development and application of SNP markers for the legume pod borer Maruca vitrata (Lepidoptera: Crambidae).
- Author
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Venu M Margam, Brad S Coates, Darrell O Bayles, Richard L Hellmich, Tolulope Agunbiade, Manfredo J Seufferheld, Weilin Sun, Jeremy A Kroemer, Malick N Ba, Clementine L Binso-Dabire, Ibrahim Baoua, Mohammad F Ishiyaku, Fernando G Covas, Ramasamy Srinivasan, Joel Armstrong, Larry L Murdock, and Barry R Pittendrigh
- Subjects
Medicine ,Science - Abstract
The legume pod borer, Maruca vitrata (Lepidoptera: Crambidae), is an insect pest species of crops grown by subsistence farmers in tropical regions of Africa. We present the de novo assembly of 3729 contigs from 454- and Sanger-derived sequencing reads for midgut, salivary, and whole adult tissues of this non-model species. Functional annotation predicted that 1320 M. vitrata protein coding genes are present, of which 631 have orthologs within the Bombyx mori gene model. A homology-based analysis assigned M. vitrata genes into a group of paralogs, but these were subsequently partitioned into putative orthologs following phylogenetic analyses. Following sequence quality filtering, a total of 1542 putative single nucleotide polymorphisms (SNPs) were predicted within M. vitrata contig assemblies. Seventy one of 1078 designed molecular genetic markers were used to screen M. vitrata samples from five collection sites in West Africa. Population substructure may be present with significant implications in the insect resistance management recommendations pertaining to the release of biological control agents or transgenic cowpea that express Bacillus thuringiensis crystal toxins. Mutation data derived from transcriptome sequencing is an expeditious and economical source for genetic markers that allow evaluation of ecological differentiation.
- Published
- 2011
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