Plant & Animal Genome V Conference
Town & Country Hotel, San Diego, CA, January 12-16, 1997.
PAG-V: W72 - UNRAVELLING ASSOCIATIONS BETWEEN QTL IN POTATO
W72
UNRAVELLING ASSOCIATIONS BETWEEN QTL IN POTATO
VAN ECK, HERMAN J.(1), Leontine Colon(2), Evert Jacobsen(2)
1. Department of Plant Breeding, Wageningen Agricultural University, P.O. Box 386, 6700 AJ Wageningen, The Netherlands
2. CPRO-DLO
QTL-analysis on various agronomically important traits showed that in certain regions of the potato genome many QTLs are genetically clustered. This observation was in agreement with trait associations already well known in practical breeding. The trait associations could be (1) genetical (close linkage of QTLs or pleiotropism), (2) physiological, where the QTL is directly or indirectly involved in the expression of more than one trait, or (3) logical, where trait evaluation (size grading vs. tuber number) or trait definition (starch content vs specific gravity) caused the associations. In a diploid population from non-inbred parents a cluster of significant QTLs (resistance to late blight, second tuber growth, dormancy, specific gravity and cooking type), was detected at a genomic position indistinguishable from the El locus. However, the El locus on chromosome 5, initially identified as a major-QTL for earliness (vine maturity), is involved in profound differences in plant growth and development. As a consequence of genetic segregation at the El locus in our mapping population, the variation in the performance of other traits is regarded as a direct or indirect effect of the genotype at the El locus. Further characterization of the El locus demonstrated multiallelism and intralocus allele interactions. The application of the computer programm MapQTL-CP (see abstract Van Ooijen and Maliepaard) for QTLs analysis in cross pollinated species will bediscussed.