The objective of this work was to establish a protocol for the rootstock of 420-A micropropagation. The establishment of the cultures was accomplished with nodal segments, whose source of explants was the budding of woody stakes stored under refrigeration. In the initial cultivation were tested: the effect of 6-benzilaminopurine and kinetin with 0, 1, 5 and 10 µM concentrations, different culture medium (MS, NN and WPM) and dilutions of the basic medium (MS, MS/2, MS/4 and MS/8). In the alongation and multiplication steps were tested the following culture medium: MS, MS/2, NN and WPM. In the rooting were tested: the MS/2 culture medium with or without activated coal (1gL-1). In the acclimatization were tested the substrate vermiculite, Plantmax and carbonized rice hulls. The kinetin didn't present effect on the budding and the growth of the nodal segments. BAP already promoted an increase in the number of sprouts per explant. The increase in the concentration of BAP reduced the number of leaves emitted by explant and increased the vitrification symptoms, being the best results obtained with 1 µM of BAP. In the initial cultivation the MS medium culture with the normal concentration of salts allowed the largest growth of the buddings. The dilutions of the MS medium in ¼ and 1/8 showed very harmful to the development of the rootstock '420-A', being quite harmed the growth of the shoots after the first subcultivation. During the multiplication the medium MS/2 showed more appropriate. The roots happened naturally during the multiplication, being unnecessary the use of activated coal in the culture medium. The acclimatization was accomplished with success in a misty camera, being obtained high survival rates in vermiculite (95,8%) and Plantmax® (87%). It is concluded that the rootstock '420-A' can be micropropagated by initial cultivation of nodal segments in a culture medium of MS+1µM of BAP, multiplication by sectionalizing the shoots in MS/2 medium and acclimatization in vermiculite substratum or Plantmax®.
vine; rootstock; tissue culture; micropropagation
