Vegetative propagation of the endangered Azorean tree, Picconia azorica

• Author(s): Martins, José ; Moreira, Orlando ; Silva, Luís ; Moura, Mónica
• Date: 2011
• Persistent ID: http://hdl.handle.net/10400.3/1226
• Origin: Repositório da Universidade dos Açores
• Subject(s): Air Layering; Endemic Plants; Picconia azotica; Rooting; Stem Cuttings; Vegetative Propagation; Azores Islands
• Document Type: Article
• Language: English

Description

Picconia azorica (Tutin) Knobl. (Oleaceae), commonly named “pau-branco”, is an endangered tree endemic to the Azores. Vegetative propagation may be important for the preservation of this species, particularly in depauperate populations, with low seed set. The objective of this study was to evaluate effective techniques for the vegetative propagation of P. azorica by rooting of stem cuttings or by air layering. Rooting substrate, IBA concentration, and the portion of the area of the terminal leaf pair kept on stem cuttings, when tested in early spring (semi-hardwood cuttings) and autumn (hardwood cuttings) failed to produce any rooted cuttings. In contrast, air layering performed in the autumn on lateral branches of adult trees was successful. After 12 months, air layers treated with 5000 ppm of IBA in talc achieved 65% rooting, while those treated with 2500 ppm IBA or without growth regulator only attained 41 and 28% rooting, respectively. Our study indicates that P. azorica is relatively easy to propagate by air layering. This method could be used to restore natural populations of P. azorica when seeds are not available or plant competition impairs natural regeneration.