Micropropagation of blueberry: strategies to improve the production of seedlings of the species

Abstract

The blueberry (Vaccinium spp.) is a fruit belonging to the Ericaceae family. In recent years, this crop has been gaining more and more prominence, mainly due to its nutritional characteristics, which have aroused public interest. It is often propagated by cuttings, but in vitro cultivation is proving to be more efficient. The aim was therefore to find alternatives and strategies to improve the propagation phases of blueberries in vitro, from multiplication to acclimatization. To this end, three cultivars of the species were used: Bluegem, Climax and Woodard, which were subjected to different treatments with growth regulators (multiplication and rooting phase) and different seals (acclimatization phase). As expected, the behavior of the cultivars was different in each of the parameters analyzed (morphometric and physiological) and in each of the phases, reinforcing the idea that each requires a different micropropagation protocol. In the multiplication phase, the interaction between the concentrations of adenine sulphate and 2-ip led to an increase in the number of shoots and more uniform plants, favoring the subsequent phases of the micropropagation process. The initial inoculation of the microcuttings with IBA and the concentrations of WPM medium, with or without activated charcoal, directly affected the rooting phase of the blueberry plants. The Bluegem cultivar responded best to the treatments. The presence of activated charcoal in the culture medium was only necessary for the Climax cultivar. With regard to the percentage of WPM medium, it can be determined that 75% was the best for the Bluegem cultivar; for the others, the results were still very variable and it was not possible to determine a single concentration. The use of different types of sealing provided different results between the cultivars. The use of filter lids improved the micropropagation and acclimatization process of blueberries of the Climax cultivar and greater survival of the plants of the Bluegem cultivar, but in the Woodard cultivar the system did not provide relevant increases.