Genetic dissection of agronomic traits within a segregating population of breeding table grapes.

Grapes (Vitis vinifera) are of great economic importance worldwide. We genetically dissected a table grape breeding population, using hidden Markov models (HMM) applied to quantitative trait locus (QTL) analyses. We evaluated and dissected the following traits: total number of clusters, leaf score, peduncle length, cluster length, number of berries, weight of 10 berries, average seed number, nature of seeds, berry skin color, soluble solids, titratable acidity, and berry anthocyanin. A consensus map was developed with 255 SSR molecular markers, ordered into 19 linkage groups. The observed length of this map was 1871.4 cM, with 89.7% coverage. QTL were identified using interval mapping with HMM. The number of QTL detected for each trait varied between 1 and 8, reflecting the quantitative nature of these traits. The percentage of variation explained by these QTL was small, varying between 1.56 and 11.98%. We found QTL across linkage groups 2, 7, 12, 13, and 14 for berry anthocyanin.