GAS EXCHANGE MEMBRANES AND SILVER NITRATE REDUCE THE EFFECT OF ETHYLENE ON THE IN VITRO GROWTH OF NODAL SEGMENTS OF PASSION FRUIT (PASSIFLORA EDULIS SIMS)

The passion fruit tree has great economic importance for Brazil. Tissue culture techniques are used to aid in their propagation and conservation. However, under in vitro conditions, plants produce too much ethylene, leading to leaf senescence and problems in explant growth. The aim of this work was to minimize the effect of ethylene on the in vitro growth of nodal segments of passion fruit. To attenuate the effects of ethylene in in vitro culture flasks, gas permeable membranes were used to increase gas exchange, and the culture medium was supplemented with an inhibitor of ethylene action. The experiment was carried out in a completely randomized design, in a 5x2 factorial scheme with five concentrations of silver nitrate (AgNO3) (0.0; 2.5; 5.0; 7.5; 10.0 mg L-1) and sealed flasks with polypropylene caps with and without microporous membranes. It was observed, after 40 days of in vitro growth and 90 days of acclimatization, that there is no interaction between the treatments with membranes and with silver nitrate. Membrane treatments, by increasing gas exchange, resulted in greater plant growth in vitro and in acclimatization, and can be used in the micropropagation of passion fruit. Treatments with silver nitrate did not affect plant growth, in vitro survival and acclimatization, and it can be used for the minimum cultivation of passion fruit.