Substâncias húmicas, reguladores vegetais e substratos na propagação de mirtileiro ‘Bluecrop’

Abstract

The objective of this study was to evaluate the feasibility of using humic substances, plant regulators and differents substrates to obtain „Bluecrop‟ blueberry seedlings (Vaccinium sp.) by micropropagation. For this, three experiments were carried out, the first of which evaluated the use of humic substances added to the culture medium for the in vitro multiplication of this cultivar. The „Bluecrop‟ blueberry seedlings produced in vitro were segmented in explants containing two buds that were inoculated in WPM (Wood Plant Media) culture medium, containing the different treatments. The experimental design was in a 2X4 factorial scheme (absence or presence (100 mg.L -1 ) of 2-Isopentenyladenine) and four concentrations of humic substances (0,0; 1,0; 2,0 and 3,0 ml.L-1 ). After 90 days it was evaluated: percentage of survival, number of buds, number of sprouts, length of the largest sprout, total fresh and dry matter mass. In the second experiment, the effect of humic substances on in vitro rooting of blueberry seedlings was evaluated. The experimental design was in a 2X4 factorial scheme (absence or presence (1,0 mg.L-1 ) of indolbutyric acid) and four concentrations of humic substances (0,0; 1,0; 2,0 and 3,0 ml.L-1 ). After 90 days it was evaluated: percentage of survival, number of roots, length of the largest root, mass of fresh and total dry matter . In the third experiment, different concentrations of humic acids and substrates were tested in the ex vitro rooting of the fruit. The 3x3 factorial scheme (three types of substrates (vermiculite, carbonized rice husk and coconut fiber) and three concentrations of humic substances (0,0; 2,0 and 4,0 ml.L-1 ) were used. After 90 days it was evaluated: percentage of survival, number of roots, length of the largest root, total fresh and dry matter mass. At the end of the experiments it was concluded, under the evaluated conditions, that the use of humic substances did not positively interfere in the multiplication and rooting of the blueberry 'Bluecrop', and in the multiplication in vitro the use of 2iP showed better results, in the rooting stage in In vitro, the use of IBA is dispensed with and in rooting ex vitro the vermiculite substrate is the most suitable.