Journal of Agricultural Science; Vol. 11, No. 4; 2019 ISSN 1916-9752 E-ISSN 1916-9760 Published by Canadian Center of Science and Education 457 Heritability and Combining Ability Studies in Strawberry Population Sylvia D. Vieira 1 , Ana L. R. Araujo 1 , Douglas C. Souza 1 , Luciane V. Resende 1 , Monik E. Leite 2 & Juliano T. V. Resende 3 1 Universidade Federal de Lavras, Lavras, MG, Brazil 2 Instituto Federal do Ceará, Jaguaribe, CE, Brazil 3 Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brazil Correspondence: Douglas C. Souza, Universidade Federal de Lavras, Campus universitário, 37200-000, Lavras, MG, Brazil. Tel: 55-359-9113-6312. E-mail: douglascorrea@ymail.com Received: December 28, 2018 Accepted: January 31, 2019 Online Published: March 15, 2019 doi:10.5539/jas.v11n4p457 URL: https://doi.org/10.5539/jas.v11n4p457 Abstract The most efficient breeding strategies in crop improvement is the selection based on heritability and combing ability estimates for the traits of economic importance or commercial value. Therefore, the present study was to obtain estimates of heritability and to estimate the phenotypic and genotypic correlations among the characteristics of interest. The commercial cultivars ‘Aromas’, ‘Camarosa’, ‘Dover’, ‘Festival Flórida’, ‘Oso Grande’, ‘Sweet Charlie’ and ‘Milsei-Tudla’, and 103 F 1 hybrids from the crossbreeding experiments were evaluated for four traits of commercial fruit yield and 13 traits of fruit physical and chemical quality. The estimated genetic parameters were general combining ability, specific combining ability, genotypic correlation among traits, estimates of heritability, genetic and phenotypic variance. The ‘Camarosa’ and ‘Aromas’ cultivars were the most promising cultivars for use as parents in the commercial fruit production, while ‘Dover’ and ‘Sweet Charlie’ cultivars were selected for taste of fruit in strawberry breeding, as they showed higher concentrations of favorable alleles in the F 1 hybrid population. It was also verified some strong genetic correlations for some pairs of characteristics in the present study that may allow indirect selection. The estimation of these parameters is an important basis for decision making on the genetic engineering of strawberry. Keywords: Fragaria × ananassa Duch., diallel analysis, heritability, genetic correlations 1. Introduction The strawberry (Fragaria × ananassa Duch.) a fruit crop that belongs to the family Rosaeceae and the genus Fragaria, presenting 35 described and 11 natural species. In Brazil, seven cultivars and 103 hybrids of strawberry were evaluated for fruit mass and commercial fruit value for selections in crop’s breeding programs (Vieira et al., 2017). With the provision of advanced genetic engineering tools for development of populations with improved traits of economic value, it is important to estimate genetic parameters for the application of appropriate selection methods and greater genetic gains. In genetic improvement programs, the selection of superior individuals has been mostly based on the phenotypic evaluation of individuals from a given generation. The success in selection is associated with the degree of genetic variance in subsequent generations (Falconer, 1987). The genetic-additive variance estimators were described in Falconer (1987), and Cruz and Carneiro (2003), δ 2 A = 4δ 2 M when we consider absence of epistasis and inbreeding population (F = 0). From the values of the mean squares, obtained by the analysis of variance of the data of Miracema and Viçosa, the variance component associated with the male effect was estimated (δ 2 M), as described in Falconer (1987), Cruz and Carneiro (2003), and Gonçalves (2005). The estimation of genetic variance components of a population is of fundamental importance for the selection, evaluation and improvement of genotypes and their potential for use in a breeding program. The genetic gain depends on heritability of the trait under selection, the proposed selection method, intensity of selection, and the environment. The higher the expression level of genetic variability in relation to the environment, the greater the estimated genetic gains for the next generation (Hallauer & Filho, 1981). These gains can be computed based on the heritability values of the trait.