ISHS Acta Horticulturae 808: II International Symposium on Tomato Diseases
BREEDING FOR A LEBANESE TYPE OF TOMATO WITH COMBINED RESISTANCE TO TOMATO YELLOW LEAF CURL VIRUS, FUSARIUM AND VERTICILLIUM WILTS USING MARKER ASSISTED SELECTION TOOLS |
| Authors: | H.S. Atamian, R. Dagher, E. Gerges, H. Sobh, R. Talhouk, C. El Mohtar , Y. Abou-Jawdah |
| Keywords: | TYLCV, large sized tomato fruit, Bemisia tabaci, S. habrochaites, S. peruvianum, S. chilense |
| Abstract:
Lebanese tomatoes are valued for their taste and large fruit size. However, they are susceptible to a number of diseases, the most important is Tomato yellow leaf curl virus (TYLCV), which leads to losses close to 100%. TYLCV is considered the bottleneck for tomato production along the Lebanese coast and in many other countries in the Middle East, Europe and Africa. Lebanese tomato landraces were crossed with four parents: Lines Ih 902 and GF 13 (S. habrochaites) which carry dominant monogenic resistances to TYLCV, Fusarium oxysporum fsp. lycopercisi (FOL) race 2 and Verticillium wilt race 1.; Line GS 16 (S. chilense), which carries a major gene of resistance to TYLCV with partial dominance; Line 197 (S. peruvianum) which is believed to carry a few recessive genes that impart resistance to TYLCV. In this study, bioassays using whiteflies to inoculate tomato seedlings with TYLCV were adopted to screen for TYLCV resistance, while marker assisted selection tools were used to screen for resistance to FOL race 2 and Verticillum wilt race 1. Based on published sequences for a locus co-segregating with Verticillium resistance, we designed two primer pairs, which when used in PCR assays, allowed efficient differentiation between susceptible genotypes, homozygous and heterozygous resistant genotypes. This technique worked well with the Ih902 and GF13 parental lines used in our breeding program and was used to select individual plants with combined resistance to TYLCV and Verticillium wilt. For resistance to FOL race 2, a multiplex PCR protocol was developed and was efficiently used to detect plants with combined resistance to TYLCV and FOL race 2. At the F4 or F5 generations, tomato lines carrying combined resistance to all three pathogens were developed; however, the large fruit characteristic of the Lebanese type tomato was not yet well fixed. | |
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