Contacts between domestic livestock and wildlife at the Kruger National Park Interface of the Republic of South Africa     

Brahmbhatt DP  Fosgate GT  Dyason E  Budke CM  Gummow B  Jori F  Ward MP  Srinivasan R 《Preventive veterinary medicine》2012,103(1):16-21

One of the most important transboundary animal diseases (TADs) in the southern African region is foot-and-mouth disease (FMD). In this region, a pathway for spread of FMD virus is contacts between cattle and certain species of wildlife. The objective of this study was to evaluate contacts between cattle and wildlife in the Kruger National Park (KNP) and the adjacent Limpopo province for the time periods October 2006 to March 2007 and April to September 2007. In this study, 87 livestock owners and 57 KNP field rangers were interviewed. Fifteen (17%) livestock owners reported contacts between wildlife and cattle. More livestock owners reported observing contacts between cattle and all wildlife species during October-March than April-September (p = 0.012). However, no difference was found between these periods for contacts between cattle and individual wildlife species. A total of 18 (32%) field rangers reported contacts between cattle and wildlife. The most common species-specific contacts were between cattle and buffalo (63/year), cattle and impala (17/year) and cattle and lion (10/year). There were no significant differences in rangers reporting observed contacts between cattle and wildlife during October-March versus April-September or between rangers reporting observed contacts outside versus within the KNP. Overall, there was no evidence of higher contact rates between cattle and wildlife in the study area during October-March compared to April-September. Contact data collected in this study can be used to better understand the transmission of FMD virus in this region.  相似文献   

Screening for resistance against major lepidopteran and stem weevil pests of amaranth in Tanzania     

S. T. O. Othim  R. Srinivasan  R. Kahuthia-Gathu  T. Dubois  F. F. Dinssa  S. Ekesi  K. K. M. Fiaboe 《Euphytica》2018,214(10):182

Insect pests pose major challenges to optimum productivity of amaranth in Africa and Asia. The use of insecticides is the main control strategy, but is expensive and may pose health and environmental concerns, especially if proper care is not taken. Host plant resistance offers a cheap and sustainable pest management alternative. Open field experiments were conducted during two cropping seasons in 2016 and 2017 to screen 35 amaranth accessions and lines for resistance to leaf-webbers and stem weevils. The diversity (H) of lepidopteran defoliators and their parasitoids on each accession ranged from 0.00 to 1.57 and 0.00 to 1.65, respectively during the long rainy season and from 0.00 to 1.58 and 0.00 to 1.01 in the short rainy season. Accessions VI036227, RVI00027, VI054569, VI033487, VI044432, VI048076, VI049639, VI049530 and VI049698 had high levels of pest resistance with significantly lower infestations (≤?11.11?±?2.14%) and damage (≤?68.06?±?3.90%) by leaf-webbers and leaf-worms. Stem weevil infestations ranged from 68.70?±?2.0% to 90.42?±?1.0% during the long and short rainy seasons, respectively. Accessions VI047517-B, VI036227 and VI056563 had the least stem weevil infestations (<?62.5%) but differences among accessions for damage incidences were non-significant. Parasitism was observed in all the accessions except seven of them. Amaranth accessions exhibiting pest resistance or at least non-preference traits are important for success of breeding programs. The importance of deploying such accessions to breed for improvement of susceptible lines (by introgression) or their release to farmers, if they have desirable horticultural traits that are required by vegetable producers and consumers, for effective management of amaranth pests is also discussed.  相似文献   

Isolation and identification of virulent <Emphasis Type="Italic">peste des petits ruminants</Emphasis> viruses from PPR outbreaks in India     

V. Balamurugan  A. Sen  G. Venkatesan  V. Yadav  V. Bhanuprakash  R. K. Singh 《Tropical animal health and production》2010,42(6):1043-1046

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Goat pox virus isolated from an outbreak at Akola,Maharashtra (India) phylogenetically related to Chinese strain     

G. Venkatesan  V. Balamurugan  R. K. Singh  V. Bhanuprakash 《Tropical animal health and production》2010,42(6):1053-1056

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Effect of FMD vaccine antigen payload on protection, sub-clinical infection and persistence following needle challenge in sheep     

Muthukrishnan Madhanmohan  Singanallur Balasubramanian Nagendrakumar  Mangamoori Lakshmi Narasu  Villuppanoor Alwar Srinivasan   《Comparative immunology, microbiology and infectious diseases》2010,33(6):e7-e13

The relationship of Foot-and-Mouth Disease (FMD) virus antigen payload and single and double vaccinations in conferring protection against virus challenge in sheep was studied. Sheep vaccinated with half the cattle dose (1 ml) containing 15 and 3.75 μg of FMDV antigen with or without booster resisted virulent challenge on 21 days post vaccination or 7 days post booster. FMDV RNA could be detected in nasal secretions in 26% of vaccinated sheep (10^3.12 to 10^3.82 viral RNA copies) on day 35 post challenge. No live virus could be isolated after 5 days post challenge indicating that the risk of transmission of disease was probably very low. The finding showed that vaccines containing antigen payload of 1.88 μg may prevent or reduce the local virus replication at the oropharynx and shedding of virus from nasal secretions and thereby reduce the amount of virus released into the environment subsequent to exposure to live virus. Sheep with no vaccination or with poor sero conversion to vaccination can be infected without overt clinical signs and became carriers.  相似文献   

Detection of intercellular adhesion genes and biofilm production in <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolated from bovine subclinical mastitis     

Nirmala B. Dhanawade  Dewanand R. Kalorey  R. Srinivasan  Sukhadeo B. Barbuddhe  Nitin V. Kurkure 《Veterinary research communications》2010,34(1):81-89

Biofilm production by Staphylococcus aureus, an important virulence factor was investigated employing phenotypic and genotypic methods. A total of 102 S. aureus isolates from bovine subclinical mastitis cases were included in the study. Maximum number of biofilm producing strains were detected by Congo red agar (CRA) method (48.03%) followed by tube method (36.27%). Tissue culture plate method (TCP) without and with destaining identified 19.60 and 29.41% of S. aureus as biofilm producers, respectively. A polymerase chain reaction for detection of intercellular adhesion genes, icaA and icaD, responsible for biofilm formation was standardized. Of the 102 S. aureus isolates investigated, 36 (35.29%) strains revealed presence of both the genes. Considering polymerase chain reaction as a standard test, CRA and TCP without destaining were the most sensitive and specific, respectively. PCR technique standardized for detection of the icaA and icaD genes is reliable for identifying biofilm producing potential of S. aureus which may help in rapid detection of biofilm-producer Staphylococci. This would allow the early application of control measures.  相似文献   

Current control methods for diamondback moth and other brassica insect pests and the prospects for improved management with lepidopteran-resistant Bt vegetable brassicas in Asia and Africa     

D. Grzywacz  A. Rossbach  A. Rauf  D.A. Russell  R. Srinivasan  A.M. Shelton 《Crop Protection》2010

The diamondback moth (DBM), Plutella xylostella (L.), remains a major pest of brassica crops worldwide. DBM has been estimated globally to cost US$ 1 billion in direct losses and control costs. Chemical control of this pest remains difficult due to the rapid development of resistance to insecticides and to their effect on natural enemies. These problems are especially severe in South Asia and Africa where lack of knowledge, limited access to newer and safer insecticides, and a favourable climate result in DBM remaining a serious year-round pest which substantially increases the cost and uncertainty of crop production. Despite these problems, application of synthetic insecticides remains overwhelmingly the most common control strategy. Biologically-based efforts to control DBM in Africa and Asia have focused strongly on parasitoid introductions. However, despite the identification and deployment of promising parasitoids in many regions, these efforts have had limited impact, often because farmers continue early-season spraying of broad-spectrum insecticides that are lethal to parasitoids and thus exacerbate DBM outbreaks. A significant driver for this pattern of insecticide use is the presence of aphids and other pests whose appearance initiates inappropriate spraying. Despite often extensive training of producers in farmer field schools, many growers seem loath to discard calendar or prophylactic spraying of insecticides. The introduction of an IPM technology that could replace the use of broad-spectrum insecticides for DBM and other key Lepidoptera is crucial if the benefits of parasitoid introduction are to be fully realised. The deployment of DBM-resistant brassicas expressing proteins from Bacillus thuringiensis could help to break this cycle of insecticide misuse and crop loss, but their deployment should be part of an integrated pest management (IPM) package, which recognises the constraints of farmers while addressing the requirement to control other Lepidoptera, aphids and other secondary pests.  相似文献   

Biopesticide based sustainable pest management for safer production of vegetable legumes and brassicas in Asia and Africa     

Ramasamy Srinivasan  Subramanian Sevgan  Sunday Ekesi  Manuele Tam 《Pest management science》2019,75(9):2446-2454

Vegetables are one of the important crops which could alleviate poverty and malnutrition among the smallholder farmers in tropical Asia and Africa. However, a plethora of pests limit the productivity of these crops, leading to economic losses. Vegetable producers overwhelmingly rely on chemical pesticides in order to reduce pest‐caused economic losses. However, over‐reliance on chemical pesticides poses serious threats to human and environmental health. Hence, biopesticides offer a viable alternative to chemical pesticides in sustainable pest management programs. Baculoviruses such as nucleopolyhedrovirus (NPV) and granulovirus (GV) have been exploited as successful biological pesticides in agriculture, horticulture and forestry. Maruca vitrata multiple nucleocapsid NPV (MaviMNPV) was found to be a unique baculovirus specifically infecting pod borer on food legumes, and it has been successfully developed as a biopesticide in Asia and Africa. Entomopathogenic fungi also offer sustainable pest management options. Several strains of Metarhizium anisopliae and Beauveria bassiana have been tested and developed as biopesticides in Asia and Africa. This review specifically focuses on the discovery and development of entomopathogenic virus and fungi‐based biopesticides against major pests of vegetable legumes and brassicas in Asia and Africa. © 2019 Society of Chemical Industry  相似文献   

Integrated breeding approaches for improving drought and heat adaptation in chickpea (Cicer arietinum L.)     

Pooran M. Gaur  Srinivasan Samineni  Mahendar Thudi  Shailesh Tripathi  Sobhan B. Sajja  Veera Jayalakshmi  Durdundappa M. Mannur  Adiveppa G. Vijayakumar  Nadigatla V. P. R. Ganga Rao  Chris Ojiewo  Asnake Fikre  Paul Kimurto  Robert O. Kileo  Nigusie Girma  Sushil K. Chaturvedi  Rajeev K. Varshney  Girish P. Dixit 《Plant Breeding》2019,138(4):389-400

Chickpea (Cicer arietinum L.) is a dry season food legume largely grown on residual soil moisture after the rainy season. The crop often experiences moisture stress towards end of the crop season (terminal drought). The crop may also face heat stress at the reproductive stage if sowing is delayed. The breeding approaches for improving adaptation to these stresses include the development of varieties with early maturity and enhanced abiotic stress tolerance. Several varieties with improved drought tolerance have been developed by selecting for grain yield under moisture stress conditions. Similarly, selection for pod set in the crop subjected to heat stress during reproductive stage has helped in the development of heat‐tolerant varieties. A genomic region, called QTL‐hotspot, controlling several drought tolerance‐related traits has been introgressed into several popular cultivars using marker‐assisted backcrossing (MABC), and introgression lines giving significantly higher yield than the popular cultivars have been identified. Multiparent advanced generation intercross (MAGIC) approach has been found promising in enhancing genetic recombination and developing lines with enhanced tolerance to terminal drought and heat stresses.  相似文献   

A fluorescence spectroscopic study on wood   总被引：1，自引：1，他引：0  

K. K. Pandey  N. K. Upreti  V. V. Srinivasan 《Wood Science and Technology》1998,32(4):309-315

Summary Fluorescence spectroscopy has been suggested as an important tool for identification of timber (Krishna, Chowdhury 1935; Dyer 1988; Sum et al. 1991). In the present study measurements of fluorescence excitation and emission spectra from solid wood blocks, powder and their extract in methanol from heartwood ofAcacia nilotica (Babul),Albizia lebbek (Kokko),Pterocarpus marsupium (Bijasal),Toona ciliata (Toon),Tectona grandis (Teak) andEucalyptus tereticornis (Eucalypt) have been made. Fluorescence spectra obtained from solid dry wood is independent of excitation wavelength, whereas those obtained from extracts exhibited excitation wavelength dependence indicating presence of many fluorescent chemicals. The need for systematic study of wood extracts in different polar and nonpolar solvents, which would be useful for purposes of identification of wood species, is stressed.We wish to thank Mr. A. K. Ananthanarayana, Head, W. S. P. Division, for useful suggestions. Mrs. B. S. Kamala, Scientist-SE, W. P. U. Division, for providing identified samples of wood and Professor H. B. Tripathi of Kumaun University, Nainital, for providing facilities for recording fluorescence spectra  相似文献