Radiação gama e conservação in vitro de Amoreira-preta

Abstract

Blackberry is belonging to the genus Rubus, and cultive this has great potential for growth, however, still seek improvement programs cultivars with higher productivity, taste sweeter, larger fruits, plants with upright stems and mostly thornless. Because of these needs, gamma radiation and micropropagation technique, become a possibility in the induction, monitoring and storage germplasm. With this it aimed to radiate with different doses of gamma rays, explants of blackberry established in vitro, to induce changes compared to non-irradiated explants, and seek alternatives that enable the storage of germplasm blackberry black, stored for 120 days at a temperature of 6 ° C and subsequently verify the return rate of multiplication of explants. For this, containing an axillary bud explants were irradiated with different doses of gamma radiation (0, 5, 10, 20 and 40 Gy) and cultured in vitro. For the experiment of slow growth were also used micro-cuttings with one bud, which were cultured for 30, 60, 90 and 120 days at 6 ° C and grown in culture medium with different concentrations of sucrose (15, 30 and 45 g L-1) and presence or absence of mannitol and subsequently transferred to a growth chamber with a temperature of 24 ° C for 30 days. For a percentage multiplication, length of shoot and root growth was observed with increasing radiation for both cultivars, however the length of roots increased up to 20 Gy, for both cultivars. The number of roots was increased to 5 Gy, followed by reduction according to the increase of the radiation dose for the experiment slow growth was observed a gradual increase in multiplication rate until 120 days, the presence of mannitol and sucrose in the medium culture reduced the rate of multiplication, for both cultivars, indicating the importance of these osmoregulators in slow growth. After returning to growth room, it was found that the explants returned their metabolic activities, returning the rates indicated multiplication per explant. Thus, it can be concluded that the radiation causes changes in explants of blackberry and adding osmorregulators in the culture medium provides a reduction in the rate of proliferation during the storage period the cold, but does not affect the rate multiplied after returning to room growth.