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Estimates of repeatability for selection of genotypes of seedless table grapes for Brazilian semiarid regions

da Silva Sales, Witalo, Ishikawa, Francine Hiromi, de Carvalho Souza, Emille Mayara, Nascimento, José Henrique Bernardino, de Souza, Edimara Ribeiro, de Souza Leão, Patrícia Coelho
Scientia horticulturae 2019 v.245 pp. 131-136
Vitis vinifera, breeding, cultivars, fruits, genotype, models, prediction, seeds, semiarid zones, statistical analysis, table grapes, titratable acidity, total soluble solids, vineyards
Grapevine (Vitis vinifera L.) produces one of the most consumed fruits in the world. Nonetheless, there is a lack of table grape cultivars that are adapted to Brazilian semiarid conditions. Therefore, there is a need for new table grape cultivars for formation of commercial vineyards in these areas. Thus, the objective of this study was to select promising genotypes for cultivation under semiarid conditions using the methodology of mixed models: restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) models. Eighty-one individual plants (genotypes) were evaluated, in three crop seasons, during the years 2016 and 2017, for six descriptors. The estimates of the repeatability coefficient were high for most of the key traits during table grape breeding, except for total soluble solids (°Bx), 0.28, and the ratio of total soluble solids to titratable acidity (0.30). Predicted selection gains for the 30 superior genotypes provided maximum average values of 46.84 t ha―1 per crop (the yield), 150.64 bunches per plant (number of bunches), and 745.21 g (bunch weight). The selective accuracy predicted for the six evaluated traits revealed a good degree of confidence in the inferences and high precision and selection gain. Using the minimum selection indexes proposed in this study for three crop seasons, genotypes CPATSA 01.02, 02.15, 05.02, 06.123, 15.05, 15.06, 19.06, 19.10, 21.42, and 68.06 were found to be the most promising. In this group, genotypes CPATSA 15.05 and 15.06 stood out because they are completely devoid of seeds. Therefore, these genotypes will be chosen for advanced selection to prove their potential for cultivation in Brazilian semiarid regions.