Substâncias húmicas e reguladores de crescimento na micropropagação de cultivares de framboeseira

Abstract

The use of humic substances in the micropropagation of raspberries can be a promising alternative, considering that these substances have activity similar to plant hormones, such as auxin, in addition to helping in the absorption of nutrients. Therefore, the objective was to evaluate the use of such substances and plant regulators in the multiplication and in vitro rooting of raspberry trees 'Polana' and 'Schönemann'. For this, two experiments were carried out. In the first, on multiplication, nodal segments of plants cultivated in vitro and the culture medium MS (Murashige; Skoog, 1962) were used as explants, being tested the use or not of 6-benzylaminopurine (BAP) (0 and 0.8 mg L-1) and four concentrations of humic substances (0, 1, 2 and 3 mg L-1). In the second experiment, regarding rooting, nodal segments of plants multiplied in vitro were used and the culture medium MS was used, being tested two concentrations of naphthalenoacetic acid (ANA) (0 and 0.1 mg L-1) and four concentrations humic substances (0, 1, 2 and 3 mg L-1). For both experiments, the experimental design was completely randomized, in a 2x2x4 factorial scheme, totaling 16 treatments and four repetitions with four explants each. After 60 days for the multiplication phase and 30 days for rooting, the following were evaluated: number of leaves and shoots, length of shoot and largest root, number of roots, fresh and dry mass of plant. The results indicated that in the first experiment, in general, the use of 2 and 3 mg L-1 of humic substances is sufficient for the in vitro multiplication of both raspberry cultivars. However, only for 'Polana' it is not necessary to use benzylaminopurine. In the second experiment, the use of 2 mg L-1 humic substances with the addition of naphthalene acetic acid favored the growth of the Schönemann cultivar, while 2 L-1 humic substances without adding growth regulator is indicated for 'Polana'.