Micropropagação de bananeira sob diferentes concentrações de potássio e magnésio

Abstract

The banana plant requires large amounts of nutrients to maintain an adequate development and to get high yields. One of the most demanded nutrients is potassium (K) and the nutritional interactions most studied in the field are between K, magnesium (Mg) and calcium (Ca). It is important that this knowledge is available also in the micropropagation of banana. The objective of this study was to evaluate the growth parameters and development of micropropagated banana plants under different nutritional concentrations of K and Mg, and check the contents of K, Mg and Ca absorbed by plants. The cultivars Caipira, Japira and Tropical were micropropagated under different balances of K and Mg (22:1, 20:3, 15:8, 10:13 and 5:18), in completely randomized design, in a factorial 3 x 5, totaling 15 treatments. After 60 days of culture, it was observed that MS medium with the concentration pattern 22:1 of K:Mg is suitable for micropropagation of Caipira and Japira cultivars. For the Tropical cultivar, the culture medium should be ajusted to 20:3 of K:Mg, aiming superiority in micropropagation of this cultivar. With relation to absorption of K, Mg and Ca, it was observed that the plants cultivated in vitro absorb less K and the same amount of Mg and Ca, in relation to ex vitro cultivation.