Repeatability coefficients and genetic gains in table grape progenies for the Brazilian semi-arid region

Abstract

Table grape stands out among the main fruit-bearing plants of irrigated agriculture in the São Francisco Valley region of Brazil. This study estimated repeatability and heritability coefficients and predicted genetic gains in order to select superior genotypes in grape progenies from controlled hybridizations using the Restricted Maximum Likelihood/Best Linear Unbiased Prediction (REML/BLUP) methodology. Individual plants were evaluated for the variables of production (kg per plant), number of bunches, bunch weight (g), berry diameter (mm), and soluble solids content (°Brix). We evaluated 194 hybrids from 30 crosses between Vitis vinifera and interspecific hybrids in Juazeiro, Bahia State, Brazil, over four growing seasons. Repeatability coefficients, ranging from 0.164 for soluble solids content to 0.72 for berry diameter, were estimated with accuracy values higher than 80 % for all variables, except for soluble solids content (66 %). The 30 best individuals classified for each variable exhibited genetic gains and their new estimated mean values were higher than the overall mean of the population in all variables. Regarding production and number of bunches per plant as the main variables, 15 genotypes were selected simultaneously for both variables. Among which, hybrids CPATSA 15.05, 15.06, 15.06T, and 23.103 stand out because they have trace seeds and should be selected for the following steps of genetic breeding to develop new table grape cultivars for the Brazilian semiarid region.

Repeatability coefficient estimates and optimum number of harvests in graft/rootstock combinations for 'tahiti' acid lime

“…In the results of this study, the estimated repeatability was classified as moderate for NFP and FYP and low for TFD and LFD. Similar findings have been reported for other fruit crops, such as banana (Lessa et al, 2014), sweet orange (Negreiros et al, 2008), cashew (Maia et al, 2016), guava (Quintal, Viana, Campos, Vivas, & Amaral Junior, 2017), mangaba (Fonseca et al, 2018), grapes (Leão, Nunes, & Souza, 2018), and cupuassu (Alcoforado, Pedrozo, Mayer, & Lima-Primo, 2019).…”

Multitrait selection in seedless grape hybrids in semiarid regions of Brazil

“…In contrast, Leão et al. (2018) detected higher V pp values than V te values for the yield and number of bunches but observed higher V te values than V pp values for the bunch mass and soluble solids content.…”

“…Results similar to these were reported by Carvalho et al (2023) for yield, number of bunches, bunch traits, soluble solids content, titratable acidity and ratio; Sanchéz et al (2017) for fruit production; and Sales et al (2019) for all the variables evaluated by them (yield, bunch weight, soluble solids content, and ratio), with the exception of the number of bunches, in which the V pp values were greater than the V te values. In contrast, Leão et al (2018) detected higher V pp…”

“…The environmental influence on the yield, bunch characteristics, soluble solids content, and ratio can be explained by seasonal climatic variations in the 1st and 2nd semester crops in the Submédio São Francisco Valley, together with the alternations common in consecutive seasons. V te values higher than V pp values hamper the selection of promising genotypes based on simple plant breeding methods, such as clone selection, which takes into account only the individual phenotype (Leão et al., 2018).…”