| A framework linkage map based on microsatellite markers was constructed for Vitis vinifera L., the European wine grape. The mapping population consists of 153 progeny plants from a cross of the V. vinifera cvs. Riesling x Cabernet Sauvignon. A total of 155 markers (154 microsatellite markers and 1 EST) have been mapped to twenty linkage groups (2n = 38). The map covers 1728 cM. The average distance between markers is 11.0 cM. The estimates of genome size, expected genome coverage and observed genome coverage were determined with 135 to 140 markers. Differences were observed in the estimates of genome length between parental and maternal data sets. The observed approximate genome coverage is 65% versus an expected coverage of 90%. A total of 57 linked pairs of orthologous microsatellite markers were used to estimate the meiotic recombination rate in the male and female parents. The average rate of recombination was 10.3% higher in the male than in the female parent.; Correlation and quantitative trait analysis was performed on several components of the grapevine cluster. The QTL analysis was carried out on the consensus framework linkage map. QTLs for different cluster components, fruit composition, and young shoot morphology were identified with both interval mapping and the Kruskal-Wallis rank sum test. QTLs were identified for total cluster weight, average berry weight, berry number per cluster, rachis length, number of laterals per cluster, average lateral length, and cluster density. Most of the traits that markedly affect cluster architecture showed strong correlation to each other and QTLs were identified with overlapping intervals. QTLs were also identified for three traits of fruit composition (total soluble solids, pH and titratable acidity of juice) and three traits of young shoot morphology (shoot tip color, color of upper surface of leaf and presence of prostrate hair). Potential use of QTL detection results to identify common genomic areas relating to certain morphology are also discussed. |
