Breeding selection efficiency for raspberry postharvest shelf life affected by storage temperature and harvest season

Abstract

Improved postharvest quality is an important goal for fresh-market raspberry breeding programs. To determine if warm or cold storage following harvest would better facilitate the breeding selection process for the assessment of postharvest decay and juice leakage, pesticide-free fruit from cultivars and breeding selections of red, yellow, purple, and black raspberries were stored at two temperatures. Following storage fruits were examined for decay and juice leakage rate at room-temperature (25 °C) and at a cooler temperature (5 °C). The rate of decay was much faster in room-temperature storage than in cooler storage; however, classification of genotypes as parents or discards was not always in agreement between these two temperatures. This suggests that a breeder should determine whether room-temperature storage or cooler storage more closely resembles the postharvest environment for the targeted growers. For many leakage rate comparisons, there was no advantage from either storage temperature. However, when an advantage was evident, cold storage evaluation identified a greater number of classes comparing black raspberry and purple raspberry genotypes, but warm storage evaluation identified a greater number of classes comparing red and yellow raspberry genotypes. There was complete agreement on genotype breeding disposition, indicating that a breeder could evaluate genotypes for leakage in the same storage temperature chosen to evaluate decay. Selection decisions made from evaluating floricane fruit were not always in agreement with decisions made from evaluating primocane fruit, indicating that genotypes should be evaluated in both fruiting seasons.