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.

摘要：鲜食葡萄是巴西圣弗朗西斯科河谷地区灌溉农业的主要果树作物之一。本研究采用约束极大似然/最佳线性无偏预测（Restricted Maximum Likelihood/Best Linear Unbiased Prediction，REML/BLUP）方法，估算重复力与遗传力系数并预测遗传增益，以期从受控杂交获得的葡萄后代群体中筛选优良基因型。研究针对单株产量（千克/株）、果穗数、果穗重量（克）、浆果直径（毫米）及可溶性固形物含量（°Brix）等性状开展单株评价。试验于巴西巴伊亚州茹阿泽鲁市进行，共评估了30组欧洲葡萄（Vitis vinifera）与种间杂交品种杂交得到的194个杂交品系，覆盖四个生长季。各性状的重复力系数估值介于0.164（可溶性固形物含量）至0.72（浆果直径）之间，除可溶性固形物含量的估计准确度为66%外，其余性状的估计准确度均高于80%。各性状排名前30的单株均表现出遗传增益，其估算新均值在所有性状上均高于群体总体均值。以单株产量和果穗数为主要选育性状时，可同时筛选出15个兼具优良表现的基因型。其中，CPATSA 15.05、15.06、15.06T及23.103等杂交品系表现突出，其果实带有痕量种籽，可进入后续遗传育种流程，用于培育适配巴西半干旱地区的鲜食葡萄新品种。