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A S Reddy - One of the best experts on this subject based on the ideXlab platform.
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non systemic infection of Tobacco Streak Virus on cotton in warangal district andhra pradesh
Indian Journal of Plant Protection, 2009Co-Authors: R Prasada D V J Rao, A S Reddy, S N Nigam, M K Jyotsna, K S Varaprasad, Lava P KumarAbstract:During 2005, cotton was sown on 3.67 lakh acres in Warangal district of Andhra Pradesh, 62 per cent of it being Bt seeds. Hybrid RCH - 2 Bt alone was sown on 1.20 lakh acres. During late August 2005, several farmers complained about a disease causing chlorotic/necrotic lesions on leaves accompanied occasionally with leaf purpling, necrotic buds and drying up of young bolls in their cotton fields. It was also noticed that the incidence of the disease was more on Bt cultivars, compared to non Bt cultivars. A survey was conducted in some of the cotton fields to ascertain the extent of incidence and also to collect disease samples for the identification of causal agent. Samples collected during the survey were tested by Enzyme linked immuno-sorbent assay (ELIS A) and studies carried out subsequently with cotton Tobacco Streak Virus (TSV) isolate gave interesting results, which we report hereunder.
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non transmission of Tobacco Streak Virus isolate occurring in india through the 5eeds of 5ome crop and weed hosts
Indian Journal of Plant Protection, 2009Co-Authors: R Prasada D V J Rao, A S Reddy, S N Nigam, K S Varaprasad, Lava P Kumar, Jyothirmai K Madhavi, Kanupriya Sharma, F WaliyarAbstract:Tobacco Streak Virus (TSV; genus IlarVirus, family Bromoviridae) responsible for necrosis disease in sunflower, groundnut and several forage legumes has emerged as a major threat to several crops during last one decade in India. The Virus has a wide host range comprising of variety of crops, wild species and weeds, and the Virus is transmitted through pollen assisted by thrips (Thysanoptera: Thripidae). Certain strains of TSV are known to be transmitted in seed of a range of host species. The present study investigated possible transmission of TSV isolate occurring in India in seed of naturally and experimentally infected groundnut (Arachis hypogaea), sunflower (Helianthus annuus), mungbean (Vigna radiata), marigold (Tagetes erecta), French bean (Phaseolous vulgaris), urdbean (Vigna mungo), soybean (Glycine max), Chenopodium quinoa, Gomphrena globosa and Parthenium hysterophorus. Studies revealed that TSV seed transmission was not observed in any of these host species. Implications of this finding on disease epidemiology are also discussed in this paper.
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emergence and spread of Tobacco Streak Virus menace in india and control strategies
Indian Journal of Plant Protection, 2008Co-Authors: Lava P Kumar, R Prasada D V J Rao, A S Reddy, Jyothirmai K Madhavi, K Anitha, F WaliyarAbstract:Since the first outbreak of Tobacco Streak Virus (TSV), genus IlarVirus as sunflower necrosis disease (SND) on sunflower and peanut stem necrosis disease(PSND) on groundnut in late 1990s, the Virus has been a subject of much research in India. This review considers main features of TSV in India. The Virus epidemics are very damaging to several crops in South India. Natural occurrence of TSV was recorded on bottle gourd, chilli, crossandra, cotton, cowpea, cucumber, gherkin, ixora, marigold, mungbean, niger, okra, pumpkin, safflower, sesame, soybean, sunn hemp, urdbean, and several weed species. Coat protein gene sequence of TSV isolates from various locations and hosts are 97–100% identical. The Virus is transmitted through pollen assisted by thrips (Thysanoptera: Thripidae). Epidemiological studies indicate TSV as a monocyclic disease in annual crops and asymptomatic weeds such as parthenium serve as TSV inoculum source. Attempts on identification and deployment of host resistance met with limited success. Phytosanitation and cultural methods of control were effective in reducing Virus incidence but not popularly adopted by farmers. Major efforts are on-going to develop transgenic varieties using TSV coat protein gene. Additional research is required to determine the extent of TSV spread to other crops and its economic importance, understand disease epidemiology and development of host resistance for effective Virus control, success of which will bring benefits to millions of farmers in India.
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sources of resistance to Tobacco Streak Virus in wild arachis fabaceae papilionoidae germplasm
Plant Disease, 2007Co-Authors: G Kalyani, R Prasada D V J Rao, A S Reddy, F Waliyar, Lava P Kumar, R Aruna, S N NigamAbstract:Stem necrosis disease caused by Tobacco Streak Virus (TSV), first recognized in 2000, has emerged as a potential threat to peanut (Arachis hypogaea) in southern states of India. The Virus induces severe necrosis of shoots leading to death of the plant, and plants that survive are malformed, with severe reduction in pod yield. All the currently grown peanut cultivars in India are highly susceptible to the Virus. Therefore, wild relatives of peanut were evaluated to identify potential sources of resistance to TSV infection. In all, 56 germplasm accessions from 20 wild Arachis spp. in four sections (Arachis, Erectoides, Procumbente, and Rhizomatosae), along with susceptible peanut cultivars (JL 24 and K 1375), were evaluated for resistance to TSV under greenhouse conditions using mechanical sap inoculations. Systemic Virus infection, determined by enzyme-linked immunosorbent assay (ELISA), in the test accessions ranged between 0 and 100%. Twenty-four accessions in section Arachis that had 0 to 35% systemically infected plants were retested, and systemic infection was not detected in eight of these accessions in repeated trials in the greenhouse. These are International Crops Research Institute for the Semi-Arid Tropics groundnut (ICG) accession nos. 8139, 8195, 8200, 8203, 8205, and 11550 belonging to A. duranensis; ICG 8144 belonging to A. villosa; and ICG 13210 belonging to A. stenosperma. Even though the resistant accessions had 0 to 100% TSV infection in inoculated leaves, TSV was not detected in the subsequently emerged leaves. This is the first report of TSV resistance in Arachis spp. The eight TSV resistant accessions are cross compatible with A. hypogaea for utilization in breeding for stem necrosis disease resistance.
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resistance to Tobacco Streak Virus in groundnut arachis hypogaea l
2005Co-Authors: G Kalyani, A S Reddy, S Sonali, A G S Reddy, F Waliyar, S N NigamAbstract:Groundnut stem necrosis disease, caused by Tobacco Streak Virus (TSV), is a new disease in groundnut, which appeared in 2000 in Anantapur district of Andhra Pradesh in India. Eleven groundnut bud necrosis disease (GBND) resistant genotypes of groundnut, Arachis hypogaea, along with JL 24 (susceptible control), were screened in the glasshouse for resistance to TSV. Plants were inoculated mechanically at 14 days after sowing (DAS) with 2 Virus concentrations, 1:10 and 1:100. Five genotypes showed tolerance to TSV compared with JL 24. These genotypes along with JL 24 were again screened in the glasshouse with larger plant population with 2 Virus concentrations (1:10 and 1:100) and at 2 plant ages (14 and 21 DAS) under split-split plot design. Among the 6 genotypes screened, ICGV 99029 (29.4%), ICGV 01276 (34.2%), ICGV 92267 (35.0%) and ICGV 00068 (37.4%) recorded less TSV infection than JL 24 (68.6%). In addition to their tolerance of TSV, these genotypes also possess tolerance of GBND, rust and late leaf spot. These would make good parents in a multiple disease resistance breeding programme in groundnut.
Murray Sharman - One of the best experts on this subject based on the ideXlab platform.
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field evaluation of tolerance to Tobacco Streak Virus in sunflower germplasm and observations of seasonal disease spread
Annals of Applied Biology, 2016Co-Authors: Murray Sharman, Denis M. Persley, D E Pagendam, Andre Drenth, J. E. ThomasAbstract:Strong statistical evidence was found for differences in tolerance to natural infections of Tobacco Streak Virus (TSV) in sunflower hybrids. Data from 470 plots involving 23 different sunflower hybrids tested in multiple trials over 5 years in Australia were analysed. Using a Bayesian Hierarchical Logistic Regression (BHLR) model for analysis provided: (a) a rigorous method for investigating the relative effects of hybrid, seasonal rainfall and proximity to inoculum source on the incidence of severe TSV disease; (b) a natural method for estimating the probability distributions of disease incidence in different hybrids under historical rainfall conditions; and (c) a method for undertaking all pairwise comparisons of disease incidence between hybrids while controlling the familywise error rate without any drastic reduction in statistical power. The tolerance identified in field trials was effective against the main TSV strain associated with disease outbreaks, TSV-parthenium. Glasshouse tests indicate this tolerance to also be effective against the other TSV strain found in central Queensland, TSV-crownbeard. The use of tolerant germplasm is critical to minimise the risk of TSV epidemics in sunflower in this region. We found strong statistical evidence that rainfall during the early growing months of March and April had a negative effect on the incidence of severe infection with greatly reduced disease incidence in years that had high rainfall during this period.
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epidemiology and genetic diversity of Tobacco Streak Virus and related subgroup 1 ilarViruses
2015Co-Authors: Murray SharmanAbstract:A quarter of Australia’s sunflower production is from the central highlands region of Queensland and is currently worth six million dollars ($AUD) annually. From the early 2000s a severe necrosis disorder of unknown aetiology was affecting large areas of sunflower crops in central Queensland, leading to annual losses of up to 20%. Other crops such as mung bean and cotton were also affected. This PhD study was undertaken to determine if the causal agent of the necrosis disorder was of viral origin and, if so, to characterise its genetic diversity, biology and disease cycle, and to develop effective control strategies. The research described in this thesis identified Tobacco Streak Virus (TSV; genus IlarVirus, family Bromoviridae) as the causal agent of the previously unidentified necrosis disorder of sunflower in central Queensland. TSV was also the cause of commonly found diseases in a range of other crops in the same region including cotton, chickpea and mung bean. This was the first report from Australia of natural field infections of TSV from these four crops. TSV strains have previously been reported from other regions of Australia in several hosts based on serological and host range studies. In order to determine the relatedness of previously reported TSV strains with TSV from central Queensland, we characterised the genetic diversity of the known TSV strains from Australia. We identified two genetically distinct TSV strains from central Queensland and named them based on their major alternative hosts, TSV-parthenium from Parthenium hysterophorus and TSV-crownbeard from Verbesina encelioides. They share only 81 % total-genome nucleotide sequence identity. In addition to TSV-parthenium and TSV-crownbeard from central Queensland, we also described the complete genomes of two other ilarVirus species. This proved that previously reported TSV strains, TSV-S isolated from strawberry and TSV-Ag from Ageratum houstonianum, were actually the first record of Strawberry necrotic shock Virus from Australia, and a new subgroup 1 ilarVirus, Ageratum latent Virus. Our results confirmed that the TSV strains found in central Queensland were not related to previously described strains from Australia and may represent new incursions. This is the first report of the genetic diversity within subgroup 1 ilarViruses from Australia. Based on field observations we hypothesised that parthenium and crownbeard were acting as symptomless hosts of TSV-parthenium and TSV-crownbeard, respectively. We developed strain-specific multiplex PCRs for the three RNA segments to accurately characterise the range of naturally infected hosts across central Queensland. Results described in this thesis show compelling evidence that parthenium and crownbeard are the major (symptomless) alternative hosts of TSV-parthenium and TSV-crownbeard. While both TSV strains had wide natural host ranges, the geographical distribution of each strain was closely associated with the respective distribution of their major alternative hosts. Both TSV strains were commonly found across large areas of central Queensland, but we only found strong evidence for the TSV-parthenium strain being associated with major disease outbreaks in nearby crops. The findings from this study demonstrate that both TSV-parthenium and TSV-crownbeard have similar life cycles but some critical differences. We found both TSV strains to be highly seed transmitted from their respective major alternative hosts from naturally infected mother plants and survived in seed for more than 2 years. We conclusively demonstrated that both TSV strains were readily transmitted via Virus-infected pollen taken from the major alternative hosts. This transmission was facilitated by the most commonly collected thrips species, Frankliniella schultzei and Microcephalothrips abdominalis. These results illustrate the importance of seed transmission and efficient thrips vector species for the effective survival of these TSV strains in an often harsh environment and enables the rapid development of TSV disease epidemics in surrounding crops. Results from field surveys and inoculation tests indicate that parthenium is a poor host of TSV-crownbeard. By contrast, crownbeard was naturally infected by, and an experimental host of TSV-parthenium. However, this infection combination resulted in non-viable crownbeard seed. These differences appear to be an effective biological barrier that largely restricts these two TSV strains to their respective major alternative hosts. Based on our field observations we hypothesised that there were differences in relative tolerance to TSV infection between different sunflower hybrids and that seasonal variation in disease levels was related to rainfall in the critical early crop stage. Results from our field trials conducted over multiple years conclusively demonstrated significant differences in tolerance to natural infections of TSV-parthenium in a wide range of sunflower hybrids. Glasshouse tests indicate the resistance to TSV-parthenium identified in the sunflower hybrids is also likely to be effective against TSV-crownbeard. We found a significant negative association between TSV disease incidence in sunflowers and accumulated rainfall in the months of March and April with increasing rainfall resulting in reduced levels of disease. Our results indicate that the use of tolerant sunflower germplasm will be a critical strategy to minimise the risk of TSV epidemics in sunflower.
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natural host range thrips and seed transmission of distinct Tobacco Streak Virus strains in queensland australia
Annals of Applied Biology, 2015Co-Authors: Murray Sharman, J. E. Thomas, Denis M. PersleyAbstract:Diseases caused by Tobacco Streak Virus (TSV) have resulted in significant crop losses in sunflower and mung bean crops in Australia. Two genetically distinct strains from central Queensland, TSV-parthenium and TSV-crownbeard, have been previously described. They share only 81% total-genome nucleotide sequence identity and have distinct major alternative hosts, Parthenium hysterophorus (parthenium) and Verbesina encelioides (crownbeard). We developed and used strain-specific multiplex Polymerase chain reactions (PCRs) for the three RNA segments of TSV-parthenium and TSV-crownbeard to accurately characterise the strains naturally infecting 41 hosts species. Hosts included species from 11 plant families, including 12 species endemic to Australia. Results from field surveys and inoculation tests indicate that parthenium is a poor host of TSV-crownbeard. By contrast, crownbeard was both a natural host of, and experimentally infected by TSV-parthenium but this infection combination resulted in non-viable seed. These differences appear to be an effective biological barrier that largely restricts these two TSV strains to their respective major alternative hosts. TSV-crownbeard was seed transmitted from naturally infected crownbeard at a rate of between 5% and 50% and was closely associated with the geographical distribution of crownbeard in central Queensland. TSV-parthenium and TSV-crownbeard were also seed transmitted in experimentally infected ageratum (Ageratum houstonianum) at rates of up to 40% and 27%, respectively. The related subgroup 1 ilarVirus, Ageratum latent Virus, was also seed transmitted at a rate of 18% in ageratum which is its major alternative host. Thrips species Frankliniella schultzei and Microcephalothrips abdominalis were commonly found in flowers of TSV-affected crops and nearby weed hosts. Both species readily transmitted TSV-parthenium and TSV-crownbeard. The results are discussed in terms of how two genetically and biologically distinct TSV strains have similar life cycle strategies in the same environment.
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genetic diversity and epidemiology of Tobacco Streak Virus and related subgroup 1 ilarViruses
2015Co-Authors: Murray SharmanAbstract:A quarter of Australia’s sunflower production is from the central highlands region of Queensland and is currently worth six million dollars ($AUD) annually. From the early 2000s a severe necrosis disorder of unknown aetiology was affecting large areas of sunflower crops in central Queensland, leading to annual losses of up to 20%. Other crops such as mung bean and cotton were also affected. This PhD study was undertaken to determine if the causal agent of the necrosis disorder was of viral origin and, if so, to characterise its genetic diversity, biology and disease cycle, and to develop effective control strategies. The research described in this thesis identified Tobacco Streak Virus (TSV; genus IlarVirus, family Bromoviridae) as the causal agent of the previously unidentified necrosis disorder of sunflower in central Queensland. TSV was also the cause of commonly found diseases in a range of other crops in the same region including cotton, chickpea and mung bean. This was the first report from Australia of natural field infections of TSV from these four crops. TSV strains have previously been reported from other regions of Australia in several hosts based on serological and host range studies. In order to determine the relatedness of previously reported TSV strains with TSV from central Queensland, we characterised the genetic diversity of the known TSV strains from Australia. We identified two genetically distinct TSV strains from central Queensland and named them based on their major alternative hosts, TSV-parthenium from Parthenium hysterophorus and TSV-crownbeard from Verbesina encelioides. They share only 81 % total-genome nucleotide sequence identity. In addition to TSV-parthenium and TSV-crownbeard from central Queensland, we also described the complete genomes of two other ilarVirus species. This proved that previously reported TSV strains, TSV-S isolated from strawberry and TSV-Ag from Ageratum houstonianum, were actually the first record of Strawberry necrotic shock Virus from Australia, and a new subgroup 1 ilarVirus, Ageratum latent Virus. Our results confirmed that the TSV strains found in central Queensland were not related to previously described strains from Australia and may represent new incursions. This is the first report of the genetic diversity within subgroup 1 ilarViruses from Australia. Based on field observations we hypothesised that parthenium and crownbeard were acting as symptomless hosts of TSV-parthenium and TSV-crownbeard, respectively. We developed strain-specific multiplex PCRs for the three RNA segments to accurately characterise the range of naturally infected hosts across central Queensland. Results described in this thesis show compelling evidence that parthenium and crownbeard are the major (symptomless) alternative hosts of TSV-parthenium and TSV-crownbeard. While both TSV strains had wide natural host ranges, the geographical distribution of each strain was closely associated with the respective distribution of their major alternative hosts. Both TSV strains were commonly found across large areas of central Queensland, but we only found strong evidence for the TSV-parthenium strain being associated with major disease outbreaks in nearby crops. The findings from this study demonstrate that both TSV-parthenium and TSV-crownbeard have similar life cycles but some critical differences. We found both TSV strains to be highly seed transmitted from their respective major alternative hosts from naturally infected mother plants and survived in seed for more than 2 years. We conclusively demonstrated that both TSV strains were readily transmitted via Virus-infected pollen taken from the major alternative hosts. This transmission was facilitated by the most commonly collected thrips species, Frankliniella schultzei and Microcephalothrips abdominalis. These results illustrate the importance of seed transmission and efficient thrips vector species for the effective survival of these TSV strains in an often harsh environment and enables the rapid development of TSV disease epidemics in surrounding crops. Results from field surveys and inoculation tests indicate that parthenium is a poor host of TSV-crownbeard. By contrast, crownbeard was naturally infected by, and an experimental host of TSV-parthenium. However, this infection combination resulted in non-viable crownbeard seed. These differences appear to be an effective biological barrier that largely restricts these two TSV strains to their respective major alternative hosts. Based on our field observations we hypothesised that there were differences in relative tolerance to TSV infection between different sunflower hybrids and that seasonal variation in disease levels was related to rainfall in the critical early crop stage. Results from our field trials conducted over multiple years conclusively demonstrated significant differences in tolerance to natural infections of TSV-parthenium in a wide range of sunflower hybrids. Glasshouse tests indicate the resistance to TSV-parthenium identified in the sunflower hybrids is also likely to be effective against TSV-crownbeard. We found a significant negative association between TSV disease incidence in sunflowers and accumulated rainfall in the months of March and April with increasing rainfall resulting in reduced levels of disease. Our results indicate that the use of tolerant sunflower germplasm will be a critical strategy to minimise the risk of TSV epidemics in sunflower.
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distribution in australia and seed transmission of Tobacco Streak Virus in parthenium hysterophorus
Plant Disease, 2009Co-Authors: Murray Sharman, Denis M. Persley, J. E. ThomasAbstract:Tobacco Streak Virus (TSV) was found to commonly occur in Parthenium hysterophorus, as symptomless infections, in central Queensland, Australia across a large area infested with this weed. Several isolates of TSV collected across the geographic range of P. hysterophorus were found to share identical coat protein sequence with each other and with TSV from crop plants in the same area. Seed transmission of TSV in P. hysterophorus was found to occur at rates of 6.8 to 48%. There was almost no change in the rate of TSV seed transmission when P. hysterophorus seed was stored for up to 24½ months. Implications of this relationship between TSV and P. hysterophorus for the development of Virus disease epidemics in surrounding crops are discussed.
S N Nigam - One of the best experts on this subject based on the ideXlab platform.
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non systemic infection of Tobacco Streak Virus on cotton in warangal district andhra pradesh
Indian Journal of Plant Protection, 2009Co-Authors: R Prasada D V J Rao, A S Reddy, S N Nigam, M K Jyotsna, K S Varaprasad, Lava P KumarAbstract:During 2005, cotton was sown on 3.67 lakh acres in Warangal district of Andhra Pradesh, 62 per cent of it being Bt seeds. Hybrid RCH - 2 Bt alone was sown on 1.20 lakh acres. During late August 2005, several farmers complained about a disease causing chlorotic/necrotic lesions on leaves accompanied occasionally with leaf purpling, necrotic buds and drying up of young bolls in their cotton fields. It was also noticed that the incidence of the disease was more on Bt cultivars, compared to non Bt cultivars. A survey was conducted in some of the cotton fields to ascertain the extent of incidence and also to collect disease samples for the identification of causal agent. Samples collected during the survey were tested by Enzyme linked immuno-sorbent assay (ELIS A) and studies carried out subsequently with cotton Tobacco Streak Virus (TSV) isolate gave interesting results, which we report hereunder.
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non transmission of Tobacco Streak Virus isolate occurring in india through the 5eeds of 5ome crop and weed hosts
Indian Journal of Plant Protection, 2009Co-Authors: R Prasada D V J Rao, A S Reddy, S N Nigam, K S Varaprasad, Lava P Kumar, Jyothirmai K Madhavi, Kanupriya Sharma, F WaliyarAbstract:Tobacco Streak Virus (TSV; genus IlarVirus, family Bromoviridae) responsible for necrosis disease in sunflower, groundnut and several forage legumes has emerged as a major threat to several crops during last one decade in India. The Virus has a wide host range comprising of variety of crops, wild species and weeds, and the Virus is transmitted through pollen assisted by thrips (Thysanoptera: Thripidae). Certain strains of TSV are known to be transmitted in seed of a range of host species. The present study investigated possible transmission of TSV isolate occurring in India in seed of naturally and experimentally infected groundnut (Arachis hypogaea), sunflower (Helianthus annuus), mungbean (Vigna radiata), marigold (Tagetes erecta), French bean (Phaseolous vulgaris), urdbean (Vigna mungo), soybean (Glycine max), Chenopodium quinoa, Gomphrena globosa and Parthenium hysterophorus. Studies revealed that TSV seed transmission was not observed in any of these host species. Implications of this finding on disease epidemiology are also discussed in this paper.
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sources of resistance to Tobacco Streak Virus in wild arachis fabaceae papilionoidae germplasm
Plant Disease, 2007Co-Authors: G Kalyani, R Prasada D V J Rao, A S Reddy, F Waliyar, Lava P Kumar, R Aruna, S N NigamAbstract:Stem necrosis disease caused by Tobacco Streak Virus (TSV), first recognized in 2000, has emerged as a potential threat to peanut (Arachis hypogaea) in southern states of India. The Virus induces severe necrosis of shoots leading to death of the plant, and plants that survive are malformed, with severe reduction in pod yield. All the currently grown peanut cultivars in India are highly susceptible to the Virus. Therefore, wild relatives of peanut were evaluated to identify potential sources of resistance to TSV infection. In all, 56 germplasm accessions from 20 wild Arachis spp. in four sections (Arachis, Erectoides, Procumbente, and Rhizomatosae), along with susceptible peanut cultivars (JL 24 and K 1375), were evaluated for resistance to TSV under greenhouse conditions using mechanical sap inoculations. Systemic Virus infection, determined by enzyme-linked immunosorbent assay (ELISA), in the test accessions ranged between 0 and 100%. Twenty-four accessions in section Arachis that had 0 to 35% systemically infected plants were retested, and systemic infection was not detected in eight of these accessions in repeated trials in the greenhouse. These are International Crops Research Institute for the Semi-Arid Tropics groundnut (ICG) accession nos. 8139, 8195, 8200, 8203, 8205, and 11550 belonging to A. duranensis; ICG 8144 belonging to A. villosa; and ICG 13210 belonging to A. stenosperma. Even though the resistant accessions had 0 to 100% TSV infection in inoculated leaves, TSV was not detected in the subsequently emerged leaves. This is the first report of TSV resistance in Arachis spp. The eight TSV resistant accessions are cross compatible with A. hypogaea for utilization in breeding for stem necrosis disease resistance.
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resistance to Tobacco Streak Virus in groundnut arachis hypogaea l
2005Co-Authors: G Kalyani, A S Reddy, S Sonali, A G S Reddy, F Waliyar, S N NigamAbstract:Groundnut stem necrosis disease, caused by Tobacco Streak Virus (TSV), is a new disease in groundnut, which appeared in 2000 in Anantapur district of Andhra Pradesh in India. Eleven groundnut bud necrosis disease (GBND) resistant genotypes of groundnut, Arachis hypogaea, along with JL 24 (susceptible control), were screened in the glasshouse for resistance to TSV. Plants were inoculated mechanically at 14 days after sowing (DAS) with 2 Virus concentrations, 1:10 and 1:100. Five genotypes showed tolerance to TSV compared with JL 24. These genotypes along with JL 24 were again screened in the glasshouse with larger plant population with 2 Virus concentrations (1:10 and 1:100) and at 2 plant ages (14 and 21 DAS) under split-split plot design. Among the 6 genotypes screened, ICGV 99029 (29.4%), ICGV 01276 (34.2%), ICGV 92267 (35.0%) and ICGV 00068 (37.4%) recorded less TSV infection than JL 24 (68.6%). In addition to their tolerance of TSV, these genotypes also possess tolerance of GBND, rust and late leaf spot. These would make good parents in a multiple disease resistance breeding programme in groundnut.
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mechanism of transmission of Tobacco Streak Virus by scirtothrips dorsalis frankliniella schultzei and megalurothrips usitatus in groundnut arachis hypogaea l
Journal of Oilseeds Research, 2005Co-Authors: Sonali Shukla, F Waliyar, G Kalyani, N Kulkarni, S N NigamAbstract:This paper summarizes the results from experiments designed to further study Virus-vector-pollen-hosts relationships in groundnut. The mechanism of Tobacco Streak Virus (TSV) transmission in groundnut and other host crops is different from that of other Viruses in plants. There was no leaf-to-leaf transmission of TSV by adults of all three thrips species studied (S. dorsalis, F. schultzei and M. usitatus) and by nymphs of S. dorsalis and F. schultzei in groundnut and cowpea, as they did not acquire Virus from infected plants. However, they assisted in TSV transmission in groundnut and cowpea in the presence of pollen from TSV-infected sunflower plants by causing injury to both leaf tissue of host plants and pollen.
D V R Reddy - One of the best experts on this subject based on the ideXlab platform.
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the host range of Tobacco Streak Virus in india and transmission by thrips
Annals of Applied Biology, 2003Co-Authors: R Prasada D V J Rao, Chander S Rao, A S Reddy, Sandeep Reddy, K Thirumaladevi, Manoj V Kumar, K Subramaniam, Yellamanda T Reddy, S N Nigam, D V R ReddyAbstract:Tobacco Streak Virus (TSV) recently caused an epidemic in peanut (= groundnut, Arachis hypogaea) crops in Andhra Pradesh, India. In the epidemic area TSV occurred in many widely distributed weeds of which Parthenium hysterophorus probably plays a major role in its spread by thrips. Three thrips species, Megalurothrips usitatus, Frankliniella schultzei and Scirtothrips dorsalis were vectors in the presence of infected pollen. Of crop species, Helianthus annuus (sunflower) and Tagetes patula (marigold) could act as sources of inoculum. In limited tests, the Virus was not seed-transmitted in the peanut cultivar JL-24 or in the sunflower hybrids KBSH-41, -42, -44, and -50, MSFH-17 and ZSH-976. Strategies adopted to reduce the incidence of TSV are discussed.
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occurrence of Tobacco Streak Virus on peanut arachis hypogaea in india
Plant Disease, 2002Co-Authors: A S Reddy, M. A. Mayo, R Prasada D V J Rao, Sandeep Reddy, K Thirumaladevi, K Subramaniam, I M Roberts, Tatineni Satyanarayana, D V R ReddyAbstract:A Virus disease of peanut (groundnut, Arachis hypogaea L.), characterized by necrosis of the stem and terminal leaflets followed by death, caused severe crop losses in Andhra Pradesh, India during the rainy season of the year 2000. The disease was referred to as peanut stem necrosis disease (PSND). Cowpea (Vigna unguiculata, cv. C-152) and Phaseolus vulgaris (cv. Topcrop) were found to be suitable for propagating the Virus. In laboratory inoculation tests, the Virus was found to infect a large number of plants. In laboratory tests, the Virus was transmitted by the thrips Frankliniella schultzei. Virus particles were purified by differential centrifugation and sucrose density gradient centrifugation from infected cowpea plants and were used to elicit the production of a rabbit polyclonal antiserum with high titer. Extracts of infected plants reacted with antiserum to Tobacco Streak Virus (TSV). Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins extracted from purified Virus particles showed them to contain a major protein of 28 kDa and a minor, though prominent, protein of 57 kDa. Gel electrophoresis of RNA extracted from Virus particles resolved it into four species with estimated sizes of 3.7, 3.1, 2.2, and 0.9 kb. Complementary DNA (cDNA) was made using as template a sample of the 2.2-kb RNA 3 and as primer an oligonucleotide complementary to sequence in RNA 3 of TSV. Following second strand synthesis, the cDNA was cloned in pBluescript and the nucleotide sequence was obtained for 868 nt of the cDNA. The sequence was 88.4% identical to the sequence in RNA 3 of TSV (strain WC). The results indicate that the causal agent of PSND is TSV. The same Virus also was found to cause sunflower necrosis, an economically important disease in India. Studies on the epidemiology of PSND and the identification of Virus-resistant peanut genotypes have been initiated to devise strategies to control PSND.
Lee Gehrke - One of the best experts on this subject based on the ideXlab platform.
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viral coat protein peptides with limited sequence homology bind similar domains of alfalfa mosaic Virus and Tobacco Streak Virus rnas
Journal of Virology, 1998Co-Authors: M M Swanson, Patricia Anselmckinney, Felicia Houserscott, Vidadi Yusibov, Sue L Loeschfries, Lee GehrkeAbstract:An unusual and distinguishing feature of alfalfa mosaic Virus (AMV) and ilarViruses such as Tobacco Streak Virus (TSV) is that the viral coat protein is required to activate the early stages of viral RNA replication, a phenomenon known as genome activation. AMV-TSV coat protein homology is limited; however, they are functionally interchangeable in activating Virus replication. For example, TSV coat protein will activate AMV RNA replication and vice versa. Although AMV and TSV coat proteins have little obvious amino acid homology, we recently reported that they share an N-terminal RNA binding consensus sequence (Ansel-McKinney et al., EMBO J. 15:5077-5084, 1996). Here, we biochemically compare the binding of chemically synthesized peptides that include the consensus RNA binding sequence and lysine-rich (AMV) or arginine-rich (TSV) environment to 3'-terminal TSV and AMV RNA fragments. The arginine-rich TSV coat protein peptide binds viral RNA with lower affinity than the lysine-rich AMV coat protein peptides; however, the ribose moieties protected from hydroxyl radical attack by the two different peptides are localized in the same area of the predicted RNA structures. When included in an infectious inoculum, both AMV and TSV 3'-terminal RNA fragments inhibited AMV RNA replication, while variant RNAs unable to bind coat protein did not affect replication significantly. The data suggest that RNA binding and genome activation functions may reside in the consensus RNA binding sequence that is apparently unique to AMV and ilarVirus coat proteins.
