Collection periods in the in vitro establishment of raspberry tree cultivars

Abstract

The raspberry tree, a species from the Rosaceae family and the Rubus genus, is included in the group of small fruit that has been drawing the attention of the global consuming market for carrying antioxidant properties and substances capable of fighting free radicals, bringing health benefits. The objective of this work was to evaluate the effect of collection periods on the in vitro establishment of raspberry trees (Rubus idaeus L.). Explants were collected in different seasons of the year (winter, spring, summer and autumn), and were inoculated in a MS culture medium. The experimental design was totally randomized, and arranged in a factorial scheme. At 28 days, the following variables were evaluated: oxidation, fungal and bacterial contamination survival and establishment. There was less phenolic oxidation in raspberry tree explants collected in winter. Explants contamination by endogenic bacteria occurred in higher percentages in winter. Although summer was the season of the year with higher percentage of explants’ phenolic oxidation for both cultivars, the highest in vitro establishment percentages for the Heritage cultivar occurred in summer and fall. However, for the Fallgold cultivar, spring and winter were the seasons with greater in vitroestablishment.