<b>Sodium phosphate and potassium chloride concentrations: micropropagation of grapevine and blackberry</b> - DOI: 10.4025/actasciagron.v29i4.423

Abstract

This work aimed to test different concentrations of sodium phosphate (NaH₂PO₄.H₂O) and potassium chloride (KCl) taken from the White medium and added to the Knudson culture medium, in the in vitro multiplication of grapevine rootstocks and blackberry. The culture medium was constituted of Knudson salts, added of 25 g L^-1 of sucrose and 6 g L^-1 of agar, and the adjusted pH to 5.8 before the sterilization at 121ºC and 1 atm for 20 minutes. The treatments consisted of concentrations of NaH₂PO₄.H₂O(0, 125, 250, 500 and 1000 mg L^-1) and of KCl (0, 125, 250, 500 and 1000 mg L^-1), in all possible combinations, and of grapevine rootstocks ‘R110’ and blackberry cv. Cherokee. Nodal segments originated from in vitro pre-established plants were excised and introduced in test tubes containing 15 mL of culture medium. Subsequently, the tubes were transferred into a growth room at 25 ± 2ºC, irradiance of 32 umol m^-2 s^-1 and photoperiod of 16 hours. The experiment design was completely randomized, with 4 repetitions and 12 plants each. The experiment was evaluated after 60 days of in vitro cultivation. The largest length of the aerial part and fresh weight of the callus were verified in the Knudson culture medium, in the absence of potassium chloride. The addition of potassium chloride in the Knudson culture medium did not influence length increase of the aerial part in both fruit trees; neither did it influence the increase of fresh mass of callus of grapevine rootstocks ‘R110’. It is not necessary to add sodium phosphate to Knudson in order to obtain larger fresh mass in the aerial part of both fruit trees.