| Abstract Detail
Breeding and Genetics Khu, Dong-Man [1], Lorenzen, Jim [2], Love, Stephen [1]. Interval Mapping of Quantitative Trait Loci for Corky Ringspot Disease Resistance in a Tetraploid Potato Population (Solanum tuberosum subsp. tuberosum). CORKY ringspot disease (CRS) in potatoes is caused by tobacco rattle virus (TRV), which is vectored by stubby root nematode species (Paratrichondorus, Tricondorus spp.). It is difficult to evaluate resistant clones and varieties largely due to the complexity of screening procedures which require large trials with numerous replications to adequately confirm resistance. It is an ideal subject for breeding using molecular markers. However, development of such a breeding method has lagged due to the lack of genetic information for CRS resistance. The objectives of this study were to 1) construct a linkage map for a tetraploid potato population, and 2) determine the map position of the quantitative trait loci (QTL) for CRS resistance. A mapping population, created by a cross between PA95A33-1 (female, resistant) and A9446-7 (male, susceptible) was used to generate AFLP, SSR, and SSCP molecular marker profiles from which genetic maps for each parent were constructed. The total map length of PA95A33-1 was 2940 cM, with an average composite map length for each chromosome of 91.2 cM. This map was used to determine marker associations by interval QTL analysis of CRS resistance scores accumulated in a 4-year trial. A major QTL that explained 43% of the phenotypic variation in CRS resistance was localized on chromosome IX, with flanking AFLP markers AAC-CGT-0347 and ACG-CTG-0588. A minor QTL that explained 12% of CRS resistance was associated with distorted marker GGT-CAC-0259 which belonged to a small unanchored linkage group. The broad sense heritability of CRS resistance of this mapping population was 0.72 (?.149). The two QTLs explained 55% of the total variability. Therefore, these two QTLs explained most of the genetic component of this study.
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1 - University of Idaho, Aberdeen Reseach and Extension Center, P.O. Box 870, Aberdeen, ID, 83210, U.S.A
2 - University of Idaho, Dept. of PSES, Moscow, ID, 83844, U.S.A
Keywords:
Corky ringspot
AFLP
ssr
SSCP
QTL mapping.
Session: PAA09-2
Location: Hall of Ideas Room G/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 1:45 PM
Abstract ID:333 |
