Biotechnological efforts for the propagation of Quercus lusitanica Lam., an endangered species.

Abstract

This is the first time that a simple protocol is presented for the micropropagation and short-term conservation of Quercus lusitanica, an endemic and endangered species that is found in very restricted habitats of the Iberian Peninsula and North Africa. Branch segments from 15-20-year-old trees were forced-flushed, and the forced shoots were used as a source of explants for culture initiation. The best multiplication rates were obtained on Woody Plant Medium (WPM) supplemented with 0.1 mg l-1 benzyladenine for the genotype CDL, or 0.2 mg l-1 benzyladenine, 0.5 mg l-1 indole acetic acid and 0.2 mg l-1 zeatin in the case of the genotype SC1. Although the cultivation of shoots in the horizontal position improved the proliferation rates, the shoot vitrification was increased under these conditions. The best rooting rates were obtained on half-strength WPM supplemented with 3 mg l-1 indole-3-butyric acid for 7 days with subsequent transfer to auxin-free medium supplemented with 0.4% activated charcoal. An initial 5-day dark period was detrimental to the quality of regenerated plantlets. Well-acclimatized plantlets were transferred to the field with a 70% survival rate.