Desinfestação de segmentos nodais de mini-rosa (Rosa sp.) para o estabelecimento in vitro
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2018-07-11Autor
http://lattes.cnpq.br/3107456118755999
SILVA, Ana Caroline Miléo da
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Brazil stands out as one of the largest producers of ornamental plants in the world, with the
mini-roses (Rosa sp.) Becoming one of the best-selling potted flowers. However, in spite of the
great economic importance of mini-roses, there is a lack of general research on mini-roses,
mainly in the area of tissue culture. Generally, these plants are multiplied by vegetative
propagation through cuttings, plunging or grafting. However, these traditional propagation
methods have numerous undesirable characteristics, as they favor the spread of diseases and
pests, seasonal dependence and low multiplication rate. Due to this problem, the objective of
the work was to develop a disinfestation protocol for the in vitro establishment of mini-roses in
which nodal segments containing axillary buds were used as source of explants. In a laminar
flow hood, disinfestation was performed using 70% alcohol for 5 minutes, followed by
immersion in commercial sodium hypochlorite with different concentrations of active chlorine
(0.75%, 1.00% and 1.25%), with (10, 20 and 30 minutes) for each concentration. A total of 180
explants were inoculated in MS medium supplemented with 30 g / L sucrose.
The experimental design was completely randomized in factorial 3 x 3 with 9 treatments and 5
replicates, containing 4 explants per plot. The variables variables of contamination, survival,
necrosis, callus, number of responsive explants, number and height of the seedlings and number
of leaves were evaluated. Among the treatments, the best results were the concentration of
1.25% with the immersion time of 30 minutes, resulting in a rate of disinfestation of 45%, which
provided better conditions for in vitro establishment and development of segments nodal of
mini-roses, showing a greater number and height of shoots and without formation of necrosis
in the tissues. However, treatments with concentrations of 0.75% and 1% in the exposure time
of 10 minutes were not efficient for disinfestation of the nodal segments, presenting a
contamination rate of 100% and 90%, respectively, in the first evaluation days. Therefore, the
concentration of 1.25% sodium hypochlorite associated with the 30-minute exposure time to
the agent resulted in a higher aseptic rate of the mini-roses nodal segments, as well as higher
survival and lower occurrence of necrosis explants, further providing the best conditions for in
vitro establishment and development of nodal segments of mini roses. It should be noted that
the disinfestation index of the explants was satisfactory, since the matrix plant used came from
the field and did not undergo an aseptic pretreatment.