GERMINAÇÃO DE SEMENTES E MICROPROPAGAÇÃO DE MIRTILEIRO

Abstract

In recent years, the cultivation of blueberry (Vaccinium ashei Reade) has attracted the attention of producers, traders and consumers. However, its expansion is limited by unavailability of appropriate varieties to the different Brazilian regions, difficulties in their propagation and shortage of seedlings of quality. Understanding the processes involved in seed germination is important when seeking to obtain genetic variability and new cultivars adapted to different edaphoclimatic conditions. Yet, the micropropagation is an alternative for obtaining a large number of healthy plants, in a short time, through clonal propagation. In this context, aiming to support the crop establishment in the Campos Gerais region, it was sought in this paper to study the seminiferous propagation and micropropagation of the blueberry, being its objectives to evaluate the germination behavior and viability levels of Vaccinium ashei Reade seeds, Briteblue and Climax cultivars, by means of germination and tetrazolium tests; elaboration of protocol for establishing blueberry in vitro (Vaccinium ashei Reade) cv. Brightwell, in WPM medium, in the presence of 2iP and evaluate the influence of silver thiosulfate in this initial phase of tissue culture. In relation to the seminiferous propagation, it was observed through the germination test that blueberry seeds of cultivars Briteblue and Climax submitted to treatments derived from the combination of variables - exposure or not to KOH, substrates (SP and MS/2) and temperatures (10⁰C and 25⁰C) - requires over 46 days for the issuing of the first normal seedling, and after 6 months from the beginning of the test the germination percentage does not exceed 40%. Otherwise, the tetrazolium test, based on staining of tissues, allows the establishment of different levels of viability for seeds of cvs Briteblue and Climax. In the micropropagation of blueberry cv. Brightwell, the use of medium culture WPM, added of 5 mg.L-1 2iP, in the in vitro establishment stage from nodal segments allows to obtain primordial leaves and shoots after 30 days of cultivation, whereas the use of 45 mM of STS at this stage supports the development of vegetative buds and leaves.