Plant & Animal Genome VI Conference

W105

QTL IDENTIFICATION AND TRANSFER OF MULTIGENIC TRAITS NOT EXPRESSED IN THE RECEPTOR SPECIES

1. Dept. of Plant Breeding, 303 Bradfield Hall, Cornell Univ., N.Y. 14853
2. University of North Carolina
3. Dept of Statistics, Purdue University, West Lafayette, In 47907
4. Biotechnology Institute, Penn.State University, State College, PA, 16801
5. Central College, Biology Dept, Pella IA 50219
6. 5131 Grape St, Houston TX 77096

QTL analysis has been instrumental in identification and interspecific transfer of genomic regions that positively or negatively affect the level of an expressed trait. Examples in tomato include but are not limited to QTL for fruit size, fruit sugar type, and soluble solids. A more difficult problem exists when the trait of interest is both multigenic and not expressed in the receptor species. If two or more QTL are required for a trait to be expressed in the receptor species, the proportion of the mapping population expressing the trait, and the ability to detect and map QTL, are substantially reduced. Due to the strategy underlying QTL analysis, it is quite likely that an analysis of a multigenic trait not expressed in the receptor species will not detect all of the QTL required for and/or affecting trait expression. The transfer of the ability to produce acylsugars, which are the source of multiple pest resistance in L. pennellii, to the domestic tomato is an example of this situation. The use of a reiterative strategy to allow the identification of all of the QTL necessary and sufficient for production of biologically significant levels of acylsugars in tomato, is discussed.