Plant & Animal Genome V Conference
Town & Country Hotel, San Diego, CA, January 12-16, 1997.
PAG-V: W73 - MENDELIZING YIELD QTL IN TOMATO
W73
MENDELIZING YIELD QTL IN TOMATO
ZAMIR, DANI, Eyal Fridman, Yuval Eshed
The Hebrew University of Jerusalem, Faculty of Agriculture, P.O.Box 12, Rehovot 76100, Israel
QTL in tomato were resolved into discrete Mendelian traits through the development of nearly isogenic lines (NILs) for the entire genome. Replicated field evaluations of the lines facilitated the mapping of yield associated QTL to segments spanning only a few cM. A 6 cM Lycopersicon pennellii introgression on chromosome 9 was responsible for a highly reproducible 12-15% increase of soluble solids content of the fruit with no accompanied reducing effect on fresh yield. Comparison of NILs with and without the introgression revealed some overlapping phenotypic values between the two distributions. This wild species chromosome segment was introduced into a genetic background containing an independent introgression, which reduces total soluble solids content. As a result, a complete separation of the values of the two NILs was obtained. This allowed the determination of the genotype of individual plants based on their phenotype for the yield associated quantitative trait. Data will be presented that demonstrate the power of the NIL-QTL approach in transforming continuous variation for complex traits into a discontinuous one.