Conservação in vitro de Passiflora gibertii N. E. Brown a partir de segmentos nodais

Abstract

Fragmentation and loss of habitats resulting from human activities have increasingly threatened species, especially wild ones such as Passiflora gibertii, a passionfruit plant native to Cerrado that has food, ornamental and therapeutic potential. In this context, the use of conservation tools for these individuals, such as in vitro alternatives, becomes important. Thus, the objective of this work was to establish an in vitro conservation protocol for the species P. gibertii, using nodal segments, through the technique of storage via slow growth. For the induction of slow growth, 0,5 cm long nodal segments were used, previously isolated from micropropagated shoots with 2 mg L-1 of 6 – benzylaminopurine (BAP) and subsequently inoculated in a culture medium varying in sucrose concentrations (0, 15, 30, 45 or 60 g L-1) and types of luminosity during storage (normal, with a photon density of 50,71 μM m-2 s-1, or reduced, with a photon density of 16,66 μM m-2 s-1). Over 180 days, seedlings were evaluated for survival, number and length of shoots, number and length of roots, number of leaves and senescence index. After 90 and 180 days of growth, the shoot tips were removed and transferred to verify the ability to resume growth. At the end of 180 days, the rooted shoots were submitted to acclimatization for 60 days, to evaluate fresh weight, shoot length, roots and number of leaves. It is recommended the cultivation of nodal segments in 45 g L-1 of sucrose and storage in normal light, to obtain better growth parameters in the three stages, simultaneously. With the completion of this work, it was possible to establish an in vitro conservation protocol for P. gibertii, from the use of nodal segments, through the technique of storage via slow growth, which allowed the resumption of shoot apices growth and acclimatization of the resulting seedlings, after a 240-day cycle.