Concentrations of silver nitrate in the in vitro development and conservation of Passiflora gibertii N. E. Brown

Abstract

The aim of this study was to evaluate the effects of silver nitrate in the in vitro development and conservation of passion fruit plants. Experiments were carried out at the Laboratory of Culture and Tissues, in the National Cassava and Fruits Research Center (EMBRAPA), using microcuttings of Passiflora gibertii N. E. Br., previously cultivated in vitro. The microcuttings were placed in MS media supplemented with silver nitrate at concentrations of 0, 1, 2, 4 and 8 mg·L-1, and, during 30, 60 and 90 days, the following variables were identified: Shooting length (cm), number of roots, number and coloration of leaves. A completely randomized design with 30 replications in a split-plot scheme was employed. Polynomial regression equations were adjusted in analysis of variance to compare averages of treatments. The obtained results support the assumption of high sensitivity of passion fruit tissues to ethylene, which reflects in the lost of vigor and in the induction of culture senescence by its accumulation. Based on obtained results, and in order to mitigate this problem, it is possible to indicate an addition of 2 mg·L-1 of silver nitrate in culture media, for the micropropagation of passion fruit plant, allowing the controlling of the atmosphere inside the culture test tubes, during the establishment of explants and other steps of the process.