Volume 60 - Tomato Genetics Cooperative - University of Florida

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Combinations of introgressions Ty3a and Ty3: Line Gc21-a (Ty3a/Ty3a, DSI 0.3) was crossed to line Gh13 (Ty3/Ty3, DSI 0.4) and DSI for the F1 was 0.2. The average DSI of the commercial susceptible hybrid was 4.0 (Fig. 7). DSI 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 21-a 21-a X Gh13 Gh13 Com. Hybrid F1 families and Parents Fig. 7. Average disease severity index (DSI) and standard errors for heterozygous genotypes Gc21-a X Gh13 (Ty3a/Ty3), Gc21-a (Ty3a/Ty3a), Gh13 (Ty3/Ty3) and commercial susceptible hybrid, (com. hybrid). These results indicate that the combination of introgressions Ty3 and Ty3a confers a high level of resistance (DSI 0.2), and is not different than either of the resistant parents. 50
Conclusions: It should be recognized that not all of the comparisons contained all of the genotypes that would have been useful for making conclusions, that viruliferous whiteflies populations would have existed at different times, that several bipartite begomoviruses as well as Tomato yellow leaf curl virus would have been present, and that weather conditions may have impacted symptom expression. In general, the following observations were considered important concerning the various introgressions: 1) Ty3a was a more effective source of resistance than Ty4. 2) Ty2 either in the homozygous or heterozygous condition was not an effective source of resistance unless it was associated with another resistance gene, such as Ty3a. 3) The heterozygous families with Ty3a were not as resistant as families that were homozygous for this introgression (Fig. 6). 4) F1 hybrids with two different introgressions were highly resistant, such as Ty3a and Ty2 (Fig. 6) or Ty3a and Ty3 (Fig. 7). 5) There was considerable variation for the DSIs among the F3 families with same genotype for an introgression, which indicated that other genes were important in conditioning resistance. This was most notable in the F3 families from the cross of Gc143-2 by Gh188-2 (Fig. 5). Others have reported that several genes are involved in highest level of begomovirus resistance expression (Anbinder et al., 2009; Vidavsky and Czosnek, 1998; Zamir et al., 1994) and Anbinder et al. (2009) found that there were minor QTLs for resistance associated with both the resistant and susceptible parent used in the cross for their molecular analysis of resistance. 6) For the near future it is not enough to only use molecular markers for breeding for begomovirus resistance, but field evaluations with high levels of viruliferous whiteflies will continue to be an important part of any tomato breeding program for begomovirus resistance. Acknowledgements: This project was funded in part by grant FODECYT 54-07 to L. Mejía, by Facultad de Agronomía, Universidad de San Carlos, and by the College of Agricultural and Life Sciences, University of Wisconsin-Madison. Appreciation is expressed to Semillas Tropicales, S.A. for assistance with production of the seedlings and the field facilities. 51
Page 1 and 2: Report of the Tomato Genetics Coope
Page 3 and 4: Table of Contents Foreword 2 Announ
Page 5 and 6: Upcoming meetings: February 17-19,
Page 7 and 8: Opena et al., 1989; Celine et al.,
Page 9 and 10: esistant lines, a specific bitter t
Page 11 and 12: esistance and very large fruit (Sco
Page 13 and 14: esistance and agro-climatic adaptat
Page 15 and 16: esistance, and breeding in geograph
Page 17 and 18: acteria (vascular or not) and even
Page 19 and 20: Abinne (librarian at INRA-CRAAG, Gu
Page 21 and 22: origin Table 1. Summing up of the p
Page 23 and 24: Literature cited 1. Acosta J.C., 19
Page 25 and 26: complex. C. Allen, P. Prior and C.
Page 27 and 28: 63. Mew T.W., Ho W.C., 1977. Effect
Page 29: 93. Wang, J.-F., P. Hanson, and J.A
Page 37: Figure 9 : Pedigree of ‘CRA74’,
Page 42 and 43: provide a rationale for pyramiding
Page 44 and 45: was evaluated in relation to the pa
Page 46 and 47: The parents had average DSIs of 0.6
Page 48 and 49: The average DSI for RS families wit
Page 52 and 53: Literature Cited: Abinder, I., Reuv
Page 54 and 55: Research Papers TGC REPORT VOLUME 6
Page 56 and 57: tomatoes and peppers grown in the f
Page 58 and 59: Research Papers TGC REPORT VOLUME 6
Page 60 and 61: flowers have smaller and lighter gr
Page 62 and 63: Stoeva P., Dimaculangan 2 D., Radko
Page 64 and 65: Fig. 4: CLSM photographs of epiderm
Page 66 and 67: Revised List of Wild Species Stocks
Page 68 and 69: S. cheesmaniae (L. cheesmanii) LA04
Page 70 and 71: S. chilense (L. chilense) LA2767 Ch
Page 72 and 73: S. chmielewskii (L. chmielewskii) L
Page 74 and 75: S. galapagense (L. cheesmanii f. mi
Page 76 and 77: S. habrochaites (L. hirsutum, L. hi
Page 78 and 79: S. lycopersicoides LA4130 Pachica (
Page 80 and 81: S. lycopersicum (L. esculentum var.
Page 86 and 87: S. ochranthum LA2166 Pacopampa Caja
Page 88 and 89: S. peruvianum (L. peruvianum) LA153
Page 90 and 91: S. pimpinellifolium (L. pimpinellif
Page 96 and 97: Appendix. Wild species core collect
Page 98 and 99: 98 S. lyc. cerasiforme LA4133 LA024
Page 100 and 101:
SolCAP LA2675 LA2744 LA2779 LA2788
Page 102 and 103:
Coulibaly, Sylvaine Nunhems USA, 70
Page 104 and 105:
McCaslin, Mark FLF Tomatoes, 18591
Page 106 and 107:
Stommel, John USDA-ARS, Genetic Imp
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Volume 60 - Tomato Genetics Cooperative - University of Florida

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