PT - JOURNAL ARTICLE AU - Kazuya Koyama AU - Atsushi Kono AU - Yusuke Ban AU - Kazuhiro Iwashita AU - Hisashi Fukuda AU - Nami Goto-Yamamoto TI - Genetic Architecture Underlying Proanthocyanidin Composition in American Hybrid Grapes AID - 10.5344/ajev.2023.22046 DP - 2023 Jan 01 TA - American Journal of Enology and Viticulture PG - 0740016 VI - 74 IP - 1 4099 - http://www.ajevonline.org/content/74/1/0740016.short 4100 - http://www.ajevonline.org/content/74/1/0740016.full SO - Am J Enol Vitic.2023 Jan 01; 74 AB - Background and goals Grapes accumulate proanthocyanidins (PAs), complex polymer mixtures of flavan-3-ol units, in the skin and seeds. The composition of PAs, including subunit ratio and polymer length, and total concentration, is important because of their relationship to sensory properties of grape and wine. It is known that the grape species Vitis vinifera and Vitis labruscana have remarkably different PA concentration and composition. A mapping population derived from a cross between V. labruscana and V. vinifera was used to provide insight into the genetic architecture of PAs, as well as that of PA skin and seed properties.Methods and key findings The composition of PA subunits at the terminal and extension positions in the hybrid population’s skin and seeds was examined in great detail. Hierarchical clustering analysis of PA profiles grouped PA variables into five main clusters. There were distinct clusters related to compositional differences in skin and seeds, such as the percentage of galloylated or trihydroxylated subunits, polymer length, and the total PA concentration. A quantitative trait locus (QTL) analysis revealed several different minor loci between skin and seeds, each contributing to the phenotypic variation of total PA concentration. A few major QTLs on linkage groups 1 and 17 were discovered to contribute to the phenotypic variation of PA composition in both skin and seeds.Conclusions and significance A distinct genetic architecture between PA composition and total PA concentration in interspecific hybrid grapes was found. In contrast to PA concentration, a similar genetic architecture of PA composition was observed between skin and seeds.