Estimation of the Proportion of Offspring without Berry Cracking Based on Associations between Cracking and Other Fruit Traits in Table Grape Breeding

Abstract

To facilitate efficient breeding of table grape (Vitis spp.) cultivars with cracking resistance, we estimated the proportion of offspring with cracking resistance in a cross using data from 1373 individuals in 46 families. To estimate the proportions, we conducted logistic regression analyses using the mid-parental values (MPs) of cracking, flesh texture, and berry weight, and type of cross (interspecific hybrid × interspecific hybrid, interspecific hybrid × Vitis vinifera, and V. vinifera × V. vinifera) as explanatory variables. The proportion of offspring with cracking resistance in a cross decreased as MP of cracking increased, and as MP of flesh texture (from 0 = easy to masticate to 2 = difficult to masticate) decreased. MP of berry weight and type of cross were not effective as explanatory variables. Multiple logistic regression revealed that the most accurate model used MPs of cracking and flesh texture. The proportions of offspring in a cross with cracking resistance in which MP of cracking = 0 were estimated to be 52％ when MP of flesh texture = 0 and 91％ when MP of flesh texture = 2.0.