Begomoviruses, vectored by the sweetpotato whitefly (Bemisia tabaci), are a major threat to tomato (Solanum lycopersicum) production in many regions around the world. Of the many strains of Begomoviruses, those that cause Tomato yellow leaf curl virus (TYLCV) are among the most destructive, the most widespread, and the most well known. TYLCV-resistant cultivars are commercially available in many production regions, and most of these use the dominant Ty-1 gene. Generally, tomato growers do not like the TYLCV-resistant cultivars as well as susceptible cultivars due to linkage drag effects that reduce marketable yield, increase foliar disease infections to diseases such as early blight (Alternaria solani) and/or bacterial spot (Xanthomonas spp.). Furthermore, the Ty-1 gene is not effective against some TYLCV strains and some other Begomoviruses, such as Tomato mottle virus (ToMoV). To date, several additional resistance genes have been identified including Ty-2, Ty-3, Ty-4, ty-5, and recently Ty-6 (Hutton et al., 2012; Hutton and Scott, 2014). Whereas, the inheritance of these genes has generally been characterized in crosses with susceptible parents, epistatic relationships between resistance genes are not well understood. Combining resistance genes often provides higher levels and more broadly based resistance against various Begomoviruses (Mejia et al., 2010; Vidavski, 2007). For future breeding of cultivars with high levels of durable resistance, it will be beneficial for tomato breeders to use and/or combine multiple resistance genes. The present breeding line releases combine good horticultural and yield characteristics with Begomovirus resistance genes that have not yet been widely used commercially. These should prove useful either directly as parent lines in commercial hybrids or as sources of resistance for tomato breeders to develop their own parents for commercially acceptable hybrid cultivars.
Hutton, S.F., Ji, Y. & Scott, J.W. 2015 Fla. 8923; a tomato breeding line with begomovirus resistance gene Ty-3 in a 70-kb Solanum chilense introgression HortScience 50 1257 1259
Hutton, S.F., Scott, J.W. & Schuster, D.J. 2012 Recessive resistance to Tomato yellow leaf curl virus from the tomato cultivar Tyking is located in the same region as Ty-5 on chromosome 4 HortScience 47 324 327
Mejia, L., Teni, R.E., Garcia, B.E., Fulladolsa, A.C. & Mendez, L. 2010 Preliminary observations on the effectiveness of five introgressions for resistance to begomoviruses in tomatoes Rept. Tomato Genet. Coop. 60 41 53
Scott, J.W., Baldwin, E.A., Klee, H.J., Brecht, J.K., Olson, S.M., Bartz, J.A. & Sims, C.A. 2008 Fla. 8153 hybrid tomato; Fla. 8059 and Fla. 7907 breeding lines HortScience 43 2228 2230
Scott, J.W. & Jones, J.P. 2000 Fla. 7775 and Fla. 7781: Tomato breeding lines resistant to Fusarium crown and root rot HortScience 35 1183 1184
Vidavski, F. 2007 Exploitation of resistance genes found in wild tomato species to produce resistant cultivars; pile up of resistant genes, p. 363–372. In: H. Czosnek (ed.). Tomato yellow leaf curl virus disease: Management, molecular biology, breeding for resistance. Springer, Dordrecht, The Netherlands