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ABSTRACT: Tomato mosaic virus (ToMV) is a limiting factor for the success of pepino (Solarium muricatum) as a new crop. The effects of ToMV infection on total and marketable yield, fruit weight, length/width ratio and soluble
solids content (SSC) have been studied in two commercial clones (`Sweet Long' and `Sweet Round'). ToMV infection depressed
total yield in infected plants of `Sweet Long' (43.1%), while it had no effect on this trait in `Sweet Round' . Marketable
yield was dramatically reduced by ToMV infection in both clones, 94% in `Sweet Long' and 100% in `Sweet Round'. Infected plants
of clone `Sweet Long' had a lower weight than healthy plants. Although no differences in fruit weight were detected in `Sweet
Round' between ToMV infected and healthy plants, many fruits from infected plants showed deformities. Changes in fruit length/width
ratio and SSC as a result of ToMV infection were not relevant, but fruit quality was lower in infected fruits, most of which
had corky-like flesh. Forty-two clones from cultivated (S. muricatum), wild (S. caripense and S. tabanoense) and interspecific hybrids were tested for ToMV resistance. All but seven clones (four from S. muricatum and three from interspecific hybrids S. muricatum × S. caripense) were susceptible. Non-susceptible clones showed variable degrees of resistance and developed hypersensitive local lesions.
Among these clones the most promising as sources of variation for resistance to ToMV are those belonging to the cultivated
species. Although no immunity was found, plants from these clones remained asymptomatic and absorbance values resulting from
the DAS-ELISA tests in these plants were always lower than those of the susceptible control (cv. `Sweet Round'). These sources
of resistance may be of great utility in developing commercial clones resistant to this severe disease affecting pepino.
Euphytica 04/2012; 120(2):247-256. · 1.55 Impact Factor
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ABSTRACT: Ever since the arrival of the tomato to Spain in the 16 th century, great diversification of the crop has taken place, giving rise to a rich collection of varietal types. The 'Comunidad Valenciana', with its deep-rooted agricultural tradition, is one of the Spanish regions with the greatest diversity in traditional tomato varieties, characterised by their local adaptation and high fruit quality. Nevertheless, traditional varieties of tomato have been progressively abandoned over recent decades. A survey was carried out in the 'Huerta de Valencia' area of the 'Comunidad Valenciana' in order to evaluate the factors involved in the genetic erosion of traditional tomato varieties, as a model of the process affecting vegetable crops in Europe. The growth of urban areas that absorb horticultural land, the change in agricultural techniques, the low profitability of farms and their small size, the advanced age of farmers, the conversion of vegetable gardens to other crops and the incidence of viral diseases, have been identified as the major factors affecting genetic erosion in this analysis. The development of resistant traditional varieties through a formal plant breeding programme, and the consolidation of the specialised markets that efficiently exploit the organoleptic quality of these varieties, would help to assure the profitability of these varieties, and hence their active conservation on an on-farm basis. Consequently, the loss of these materials that make up gene combinations of an outstanding value could be prevented, and farmers would obtain a profitable alternative in a highly competitive agriculture.
International Journal of Plant Production 10/2007; 1. · 1.10 Impact Factor
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ABSTRACT: The complete nucleotide sequence of the genomes of two Spanish isolates (LE-2000 and LE-2002) from tomato and one Peruvian isolate (LP-2001) from Lycopersicon peruvianum of the Pepino mosaic virus (PepMV) were determined. The tomato isolates share identities higher than 99%, while the genome of LP-2001 had mean nucleotide identities of 95.6% to 96.0% with tomato isolates. The predicted amino acid sequences showed similarities ranging between 95.2% and 100% with TGBp3 and TGBp2 and CP proteins, respectively. In LP-2001 two main differences were found with respect to the tomato isolates; (i) the 5' untranslated region (UTR) was 2 nt shorter by deletion at position 12-13 and it had some polymorphims at the putative promoter sequence reported for PepMV tomato isolates and other potexviruses, which could be functionally significant for RNA replication, and (ii) the TGBp3 protein had two extra amino acids in the C-terminal region.
Archives of Virology 04/2005; 150(3):619-27. · 2.11 Impact Factor
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ABSTRACT: Resistance conferred by the Tsw locus from Capsicum chinense against Tomato spotted wilt virus (TSWV) has been widely used in breeding programmes. Nevertheless, this resistance depends on inoculation conditions, and isolates able to overcome it have already been detected. In this work 29 accessions of several Capsicum species have been mechanically inoculated with TSWV to identify new sources of resistance. Five accessions showed variable percentages of resistant plants, two of which did not show local lesions on inoculated leaves, suggesting that the response was not mediated through hypersensitivity. Two of these accessions also had a remarkable reduced viral accumulation compared to susceptible control. ECU-973., a C. chinense accession, showed the best performance against TSWV, with 100% resistant plants. This response was confirmed after mechanical inoculation with three different TSWV isolates. The resistance was maintained when the accession was inoculated with TSWV using a high pressure of viruliferous thrips. These results open new possibilities in the development of a durable resistance to TSWV in pepper.
Annals of Applied Biology 09/2003; 143(2):143 - 152. · 2.18 Impact Factor
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ABSTRACT: Pepino mosaic virus (PepMV), a potexvirus first described in 1980 from pepino (Solanum muricatum) plants cultivated in Peru, was isolated from diseased tomato plants in the Netherlands in 1999, and is now the cause of an emerging tomato disease in Europe. In a survey of central and southern Peru, 65 wild and four cultivated populations of Lycopersicon, as well as six populations of other species of Solanaceae, were tested for the presence of PepMV and six other viruses. Of the Lycopersicon population sampled, 23 (35.4%) reacted positively in double antibody sandwich (DAS)-enzyme-linked immunosorbent assay (ELISA) with antisera to PepMV. DAS-ELISA tests for PepMV of other solanaceous species were negative, except for one sample of pepino (Solanum muricatum). Mechanical inoculation of susceptible Lycopersicon esculentum cv. NE-1 plants with crude sap extracts of 20 of these samples confirmed that 15 of them (from the Departments of Apurimac, Arequipa and Moquegua) were infected with PepMV; these inoculated plants were also DAS-ELISA positive and, in most cases, developed symptoms. Thirteen of the infective extracts were obtained from plants of wild Lycopersicon species (three L. chilense, three L. chmielewskii, two L. parviflorum and five L. peruvianum) and one each from the cultivated species L. esculentum and S. muricatum. The wild Lycopersicon species are newly reported natural hosts of PepMV. Tests for the other six viruses were negative, except that two samples contained Tomato mosaic virus. Thus, PepMV occurs in Lycopersicon species in central and southern Peru, even in isolated wild populations. These results indicate that the virus is not new to the region and has an efficient mechanism of natural transmission.
Journal of Phytopathology 03/2002; 150(2):49 - 53. · 0.79 Impact Factor
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ABSTRACT: We evaluated the effects of treatments with thermotherapy (80°C for 24 h) and dipping in sodium hypochlorite (NaOCl; 0.8% for 10 min) on the germination percentage, germination rate, vigour index and ToMV inactivation of seeds from three pepino (Solarium muricatum) accessions (96–5, B–2 and OV–8) and two wild relatives (S. tabanoense EC–26 and S. caripense EC–40). Thermotherapy decreased the germination percentage (especially in the wild species), germination rate in wild species but not in cultivated pepino, and vigour index in all cases. Sodium hypochlorite increased germination, except for nonthermotreated seeds of OV–8, improved the germination rate in wild species and the vigour index in all cases except for non thermotreated OV–8. Seed coats were altered by both treatments, especially by NaOCl. Thermotherapy was totally effective in the inactivation of seed-borne ToMV, while NaOCl was not. Thermotherapy combined with NaOCl allows effective seed disinfection of S. muricatum seeds without negatively affecting seed germination. For the wild species, although thermotherapy reduces germination, the higher number of seeds per fruit in these species reduces the magnitude of the problem. Even when no disinfection is necessary, treatments with NaOCl are always advisable as they improve germination.
Annals of Applied Biology 05/1999; 134(3):299 - 305. · 2.18 Impact Factor
