Location: Plant Genetic Resources Research
Project Number: 8060-21000-024-10-S
Project Type: Specific Cooperative Agreement
Start Date: Jul 31, 2014
End Date: Jul 30, 2015
The objective of this cooperative research project is to discover alternative sources of race 3 resistance, since the pleiotropic negative effects (susceptibility to blossom end rot and bacterial spot, and weaker vines) that are associated with I-3 may not be factors with other resistance loci. Moreover, such novel race 3 resistance sources may provide potential solutions to new races of Fol and/or FORL which may emerge in the future.
In this study, 42 S. pennellii accessions will be evaluated for resistance to three races of Fusarium wilt and to FCR (Fusarium crown rot). Further, for each race 3 resistant accession, genetic analysis will be conducted on BC1F1 populations to determine if resistance is potentially unique, or if it co-segregates with I-3. Accessions for which resistance is not based (solely) on I-3 will be of particular interest for the present breeding goals. Phylogenetic analysis will also be conducted on all 42 accessions, providing a thorough knowledge on the relationships among theses—which will be useful to breeders and researchers may greatly benefit the tomato breeders and researchers utilizing these accessions in the future. For example, if 10 accessions were identified as containing race 3 resistance that does not co-segregate with I-3, and if limited resources dictated that only two of these could be pursued in breeding; the results of the phylogenetic analysis would be useful in determining which two accessions were most distantly related and may possibly contain different resistance genes from one another. Similarly, these phylogenetic relationships would allow one to systematically identify of a subset of representative S. pennellii accessions that might be screened for any number of future projects.