Repeatability and heritability of production characters in strawberry fruits

Abstract

The estimation of repeatability coefficient provides support to define the number and the appropriate period of genotype evaluations, obtaining better success in breeding programs, in order to lower labor costs. Therefore, knowing repeatability and heritability parameters is relevant. Thus, the aim of this study was to estimate the repeatability and heritability coefficients and accurately determine the number of measurements. Eight strawberry cultivars were analyzed in a randomized block design with four replicates and eighteen plants per plot, being harvested twice a week over a period of six months (May to October, 2012), totalizing six evaluations. Among the evaluated traits, the estimated heritabilities ranged from 3.13% (number of fruits) to 40.20% (average fruit mass) whereas the repeatability ranged from 9.00 to 42.06% for the same characters. The minimum number of evaluations, to reach a coefficient of determination with an accuracy of about 80%, ranged from the maximum of 40 for fruit number and the minimum of 6 for average fruit mass. In order to be considered commercially important marketable fruit mass, minimum of 20 evaluations are required, it means, at least, 20 months.