Tomato yellow leaf curl virus is a major disease of cultivated tomatoes ( Solanum lycopersicum L.) in many tropical and subtropical production regions of the world. TYLCV is a monopartite begomovirus in the family Geminiviridae and is transmitted
Samuel F. Hutton, Jay W. Scott, and David J. Schuster
M. Friedmann, M. Lapidot, S. Cohen, and M. Pilowsky
Tomato yellow leaf curl virus (TYLCV), transmitted by the tobacco whitefy (Bemisia tabaci Genn.), can be devastating to tomato (Lycopersicon esculentum L.) crops in tropical and subtropical regions. The development of resistant cultivars is the best option for control of TYLCV. However, all the available resistant commercial cultivars tested at the Volcani Center, when inoculated with TYLCV, developed different levels of disease symptoms. In this study, we report the development of a breeding line, TY172, which is a symptomless carrier of TYLCV. Line TY172, whether infected in the greenhouse with viruliferous whiteflies, or when grown in the field under natural infection, showed no symptoms of the disease. Viral DNA was detected in infected TY172 plants, albeit at much lower levels than a susceptible infected control. In addition, grafting experiments using infected susceptible scions grafted onto TY172 stocks, showed that even when exposed continuously to very high levels of virus, line TY172 did not develop disease symptoms, nor did it accumulate high levels of the virus. When TY172 was crossed with susceptible lines, the hybrids exhibited milder symptoms and lower viral content than the susceptible parent, yet higher than that of TY172, suggesting a partial dominance for the TY172 resistance. Upon inoculation of F2 populations, the amount of symptomless individuals appeared in a ratio of≈7:64. This suggests that at least three genes may account for the resistance.
H.A. Agrama and J.W. Scott
The genetic basis of resistance to tomato yellow leaf curl virus (TYLCV) and tomato mottle virus (ToMoV) was studied in three different mapping populations of tomato (Lycopersicon esculentum Mill.). Bulked segregant analysis (BSA) was used to identify random amplification of polymorphic DNA (RAPD) markers linked to TYLCV and ToMoV resistance. Segregated RAPD markers associated with resistance were linked to morphological markers self-pruning (sp) and potato leaf (c) on chromosome 6. RAPD genetic linkage maps of chromosome 6 were constructed for each of the three populations. Common mapped markers revealed straightforward homologies between the chromosome 6 linkage group of the three populations. Multiple-QTL mapping (MQM) was used to identify quantitative trait loci (QTL) for resistance linked to chromosome 6. These revealed that the resistance against TYLCV and ToMoV was mainly explained by two QTL in two populations and one QTL in another. For all of the resistance QTL detected, the favorable allele was provided by the resistant parents. The presence of three different sources of TYLCV and ToMoV resistance, and the markers in tight linkage with them, provide a means of systemically combining multiple resistance genes. Successful cloning of the R gene from tomatoes would lead to deeper understanding of the molecular basis of resistance to TYLCV and ToMoV, and might also shed light on the evolution of resistance genes in plants in general.
Santiago García-Martínez, Adrián Grau, Aranzazu Alonso, Pedro Carbonell, Juan F. Salinas, José A. Cabrera, and Juan J. Ruiz
years, cherry tomato has shown an increasing market share. Like all tomato landraces, cherry cultivars are susceptible to several viruses, such as Tomato mosaic virus (ToMV), Tomato spotted wilt virus (TSWV), Tomato yellow curl virus (TYLCV
Santiago García-Martínez, Adrián Grau, Aranzazu Alonso, Pedro Carbonell, Juan Francisco Salinas, José Ángel Cabrera, and Juan J. Ruiz
many tomato landraces, ‘Moruno’ cultivars are highly susceptible to several viruses, such as Tomato mosaic virus (ToMV), Tomato spotted wilt virus (TSWV), and Tomato yellow leaf curl virus (TYLCV) ( Cebolla-Cornejo et al., 2007 ), Pepino mosaic
Monica Ozores-Hampton, Philip A. Stansly, and Eugene McAvoy
T omato yellow leaf curl virus , a begomovirus, was first described in Israel in 1939 ( Picó et al., 1996 ), and subsequently became a major constraint to tomato production in the entire Mediterranean basin ( Czosnek et al., 1990 ). TYLCV is
Yuanfu Ji, John W. Scott, and David J. Schuster
Tomato yellow leaf curl virus (TYLCV) was the first monopartite begomovirus whose genome was characterized ( Navot et al., 1991 ). TYLCV infects a wide range of host plants, including tomato, pepper, potato, tobacco, and numerous dicot species
Aliya Momotaz, John W. Scott, and David J. Schuster
The begomoviruses, Tomato yellow leaf curl virus (TYLCV) and Tomato mottle virus (ToMoV), vectored by the silverleaf whitefly ( Bemisia argentifolii Bellows & Perring) can cause severe losses in tomato production. Most cultivated tomatoes are
Yuanfu Ji, Jay W. Scott, David J. Schuster, and Douglas P. Maxwell
Tomato-infecting begomoviruses, including monopartite tomato yellow leaf curl virus (TYLCV) and numerous bipartite viruses including tomato mottle virus (ToMoV), are transmitted by the sweetpotato whitefly ( Bemisia tabaci ), the B biotype of
Peter M. Hanson, Dario Bernacchi, Sylvia Green, Steven D. Tanksley, Venkataramappa Muniyappa, Attiganal S. Padmaja, Huei-mei Chen, George Kuo, Denise Fang, and Jen-tzu Chen
Tomato yellow leaf curl virus (TYLCV), a heterogeneous complex of whitefly-vectored geminiviruses, is a serious production constraint of tomato (Lycopersicon esculentum Mill.) in Asia, the Middle East, and the Americas. In this study we report on mapping of a DNA fragment introgressed into cultivated tomato presumably from the wild species L. hirsutum Humb. and Bonpl. and found to be associated with TYLCV resistance. To locate introgressions of wild tomato alleles in TYLCV-resistant tomato line H24, its DNA was digested with six restriction enzymes and probed with 90 RFLP markers evenly spaced throughout the genome. This polymorphism survey revealed the presence of one wild tomato introgression each on chromosomes 8 and 11. Plants of a F2 cross between H24 and a susceptible tomato line were probed with randomly amplified polymorphic DNA (RFLP) markers linked to the targeted regions and F3 families were developed by self-pollination of F2 plants that carried none, one, or both introgressions in either homozygous or heterozygous states. Plants of F3 families, parents, and control tomato line Ty52 (homozygous for the Ty-1 allele for TYLCV tolerance) were exposed to viruliferous whiteflies (Bemisia tabaci Gennadius) in greenhouses at the Asian Vegetable Research and Development Center, Taiwan, and the University of Agricultural Sciences, Bangalore, India. Results indicated that F3 families homozygous for the introgression on chromosome 11 were resistant to TYLCV at both locations. Additional probing showed that the chromosome 11 introgression spanned markers TG36 to TG393, covering a distance of at least 14.6 centimorgans. This is the first report of TYLCV resistance in tomato mapped to chromosome 11.