1 C.R.A., Centro di Ricerca per l'Orticoltura, Research Group of Battipaglia, S.S. 18 n. 204, 84091 Battipaglia, Salerno, Italy. 2 Istituto per la Protezione delle ...
Tomato Genotypes Resistant to Tomato Spotted Wilt Virus Evaluated in Open Field Crops in Southern Italy M. Zaccardelli1, D. Perrone1, A. Del Galdo1, F. Campanile1, G. Parrella1 and I. Giordano2 1 C.R.A., Centro di Ricerca per l’Orticoltura, Research Group of Battipaglia, S.S. 18 n. 204, 84091 Battipaglia, Salerno, Italy 2 Istituto per la Protezione delle Piante del CNR, Sezione di Portici, via Università 133, 80055 Portici, Napoli, Italy Keywords: CMV, PVY, ToMV, TSWV, Lycopersicon esculentum Abstract Tomato spotted wilt virus (TSWV) and Cucumber mosaic virus (CMV) are the main viruses responsible for severe losses in open field tomato crops in Southern Italy. Control of TSWV is possible using resistant tomato genotypes carrying the Sw5 resistance gene. The present work evaluated the incidence of viral damage and the yield of eighteen processing tomato genotypes resistant to TSWV (nine for peeling and nine for tomato concentrate), growing in open fields in the Sele Valley (Southern Italy) during summer 2004. Susceptible controls consisted of four tomato cultivars (two for peeling and two for tomato concentrate). At harvesting, the incidence of viral damage on fruits of tomato genotypes resistant to TSWV ranged from 3% to 34.3% for peeling tomato and from 0.7% to 23.7% for concentrate tomato, whereas the incidence of viral damage on the fruits of susceptible genotypes ranged from 27.7% to 37.6%. The yield of all resistant peeling tomato genotypes were statistically not significantly different from the susceptible cultivar Genius, but were lower than the susceptible cultivar Galeon. The yield of resistant tomato genotypes for concentrate was statistically not different from the susceptible cultivars. TSWV infections and those caused by other viruses were assessed by ELISA and checked in bulk leaf samples collected a few days before harvest. TSWV was detected in only one out of eighteen resistant genotypes. At least ten tomato genotypes (five for peeling and five for concentrate), resistant to TSWV, had shown a good response for lowest fruit damage as well as for satisfactory production. Finally, ELISA assays showed that all the tomato genotypes except one were resistant to TSWV populations spreading naturally in Southern Italy. INTRODUCTION Viruses are the main biotic factor limiting tomato production. Cucumber mosaic virus (CMV) is one of the most widespread and damaging viruses but during the last few years, Tomato spotted wilt virus (TSWV) has also been responsible for severe losses in open field tomato crops in Southern Italy (Parrella and Crescenzi, 2004). When available, the best strategy to control virus damage is the use of resistant tomato genotypes (Hoffmann et al., 2001). Control of TSWV is possible by using resistant tomato genotypes carrying the Sw-5 resistance gene. The present work evaluated the incidence of viral damage and the yield of eighteen processing tomato genotypes resistant to TSWV growing in open fields in the Sele Valley during summer 2004. MATERIALS AND METHODS Eighteen processing tomato genotypes (nine for peeling and nine for tomato concentrate) resistant to TSWV were cultivated in open field during spring and summer 2004 in Battipaglia, Salerno, Southern Italy (Table 1); controls were the susceptible peeling tomato genotypes Galeon and Genius and the susceptible concentrate tomato genotypes Perfect Peel and Joy. From each tomato genotype, three bulk leaf samples (one for each field replicate) were collected a few days before harvesting. Each sample was obtained by mixing 20 Proc. XVth EUCARPIA Tomato Eds.: M. Cirulli et al. Acta Hort. 789, ISHS 2008
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tomato leaflets collected from 20 tomato plants. These were performed on extracts of leaf bulks using DAS-ELISA commercial kits (Loewe). Viruses monitored were TSWV, CMV, Tomato mosaic virus (ToMV) and Potato virus Y (PVY). At harvest, 300 fruits (100 fruits per field replicate) for each genotype were scored for virus symptoms and the incidence of viral damage was calculated. All data were statistically analyzed by ANOVA and separation of means was done by Duncan’s test using the MSTAC-C software. RESULTS AND DISCUSSION Using ELISA tests, TSWV was detected only in TSWV resistant peeling tomato cv. Diaz, whereas CMV was detected in all tomato genotypes except for the tomato concentrate varieties EX 686, EX 903, NPT 80 and Donald. ToMV was detected in TSWV resistant cv. Messapico (peeling tomato) and in TSWV resistant genotypes for tomato concentrate Hmx 3860, NPT 80 and York. PVY was detected in the following peeling genotypes: NPT 555, ISI 19343, ISI 12618, Hmx 3861, Rambla, Messapico and Galeon, as well as in the concentrate genotypes: EX 903, Hmx 3860, ISI 22930 and Idillio. The incidence of viral fruit damage for tomato genotypes resistant to TSWV ranged from 3% to 34.3% in the case of peeling tomatoes and from 0.7% to 23.7% for concentrate tomatoes, whereas the incidence of viral damage on the fruits of susceptible genotypes ranged from 27.7% to 37.6% (Table 1). Yields of all resistant peeling tomato genotypes were not statistically different compared to the susceptible cultivar Genius, but were lower than the susceptible cultivar Galeon (Table 1). Yields of resistant tomato genotypes used as concentrate were statistically not different from the susceptible cultivars (Table 1). At least 10 tomato genotypes (5 for peeling and 5 for concentrate) resistant to TSWV had lower viral fruit damage as well as satisfactory yield. The higher resistance and performance of TSWV resistant genotypes was observed in the same location during 2003, where a higher pressure of viral inoculum was observed, in particular during the summer (Zaccardelli et al., 2004). The results obtained by ELISA clearly suggested that all tomato genotypes, except for Diaz, were resistant to TSWV populations naturally spreading in Southern Italy. Literature Cited Hoffmann, K., Qiu, W.P. and Moyer, J.W. 2001. Overcoming host- and pathogenmediated resistance in tomato and tobacco maps to the mRNA of Tomato spotted wilt virus. Molecular Plant Microbe Interaction 14:242–249. Parrella, G. and Crescenzi, A. 2004. The present status of tomato viruses in Italy. Proc. of the 1st International Symposium on Tomato Diseases and 19th Annual Tomato Disease Workshop, June 21–24, Orlando, Florida, USA. Zaccardelli, M., Parrella, G., Riccardi, R., Spigno, P. and Giordano, I. 2004. Field evaluation of viral damage on sixteen genotypes of canning tomato. J. Plant Pathol. 86(4):338.
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Tables Table 1. Incidence of viral fruit damage and yield of TSWV resistant and susceptible (s) genotypes of processing tomato cultivated in southern Italy. Tomato cultivars Hmx 3861 ISI 19343 Galeon (s) Genius (s) NPT 555 Rambla Herdon Diaz Scipio Messapico ISI 12618 Hmx 3860 ISI 22930 PERF. P. (s) EX 774 Idillio Joy (s) Donald EX 903 York EX 686 NPT 80
Viral symptoms on fruits (%) Peeling 34.3 a 27.7 ab 21.7 abc 21.0 abc 18.3 bc 15.3 bcd 13.0 cd 10.3 cd 9.7 cd 9.7 cd 3.0 d Concentrate 23.7 a 11.0 b 10.3 bc 10.0 bc 10.0 bc 8.0 bcd 7.6 bcd 4.7 bcd 4.3 bcd 2.7 cd 0.7 d
Yield of ripe and pre-ripe fruits (t ha-1) 58.11 62.38 84.10 67.84 60.76 55.68 63.36 63.04 65.51 54.58 66.15
b b a b b b b b b b b
79.48 72.62 92.16 94.48 77.47 82.57 82.00 72.50 86.00 78.97 67.00
abc bc a a abc abc abc bc ab abc c
Different letters indicate significative difference for P ≤ 0.05
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