title: Evaluation of genetic dissimilarity in a segregating  wine grape population.
abstract: This study examined the genetic diversity present in a  population obtained by crossing two very distinctive varieties of wine grapes  (142 progeny from a Riesling x Cabernet Sauvignon cross, including both  parents, created at the University of California). The following list of  morphological characters were evaluated and found to segregate in this  population: cluster weight, cluster length, presence or absence of cluster  wings, cluster wing length, number of berries, cluster density (CD), and berry  weight. The following juice parameters were also measured: °Brix, pH, total  phenolics, and titratable acidity. Genetic diversity within this population was  estimated through multivariate methods that utilized the Gower index of  dissimilarity and UPGMA clustering. The correlations between traits and  relative contribution of each variable were also compared. Eleven groups of  progeny were distinguished into categories with low, intermediate and high  values for cluster weight and cluster density, and low and high values for  total phenolics. An inverse correlation was detected between the variables  related to production and those related to the quality of the fruit. Principal  components analysis demonstrated that all variables examined in this study are  important for the correct discrimination of optimal genotypes in this  population. These statistical tools can be used to select individuals with the  greatest potential for producing high-quality wines.
authors.affiliation: Laboratório de Melhoramento Genético Vegetal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brasil. pirapora@uenf.br
authors.forename: A P
authors.initials: AP
authors.lastname: Viana
authors.forename: S
authors.initials: S
authors.lastname: Riaz
authors.forename: M A
authors.initials: MA
authors.lastname: Walker
mesh_terms: D020090:Chromosome Segregation / Q000235:genetics*; D003433:Crosses, Genetic; D005828:Genetics, Population; D005838:Genotype; D010641:Phenotype; D010802:Phylogeny; D025341:Principal Component Analysis; D019655:Quantitative Trait, Heritable; D027843:Vitis / Q000235:genetics*; D014920:Wine