© 1997 Heron Publishing—Victoria, Canada
In vitro regeneration of plantlets from mature embryos of Pinus ayacahuite
Francisco Saborio (1, 2), William S. Dvorak (3), Jeffrey K. Donahue (3) and Trevor A. Thorpe (1, 4)
1. Plant Physiology Research Group, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada / 2. Centro de Investigaciones Agronómicas, Universidad de Costa Rica, San José, Costa Rica / 3. CAMCORE Cooperative, Box 7626, North Carolina State University, Raleigh, NC 27695, USA / 4. Author to whom correspondence should be addressed / Received November 28, 1996
Summary
A plantlet regeneration protocol was developed for Pinus ayacahuite var. ayacahuite (Ehrenb.). Embryos from mature seeds from ten provenances were cultured in a 16-h photoperiod for 3 days on a medium containing
30 mM sucrose and 0.7% agar. Cotyledons from these embryos were subcultured onto MCM medium (Bornman 1983) supplemented with
50 µM N6-benzyladenine and 90 mM sucrose for 2 weeks. Bud development and shoot elongation were maximized by subculturing the explants
on half strength AE medium (von Arnold and Ericksson 1981), supplemented with 60 mM sucrose and 0.05% activated charcoal every
30 days. Seed source had a significant effect on the responses of the embryos to the bud induction protocol. For the provenance
with the best response to bud induction, about 79% of the cultured cotyledons formed buds, and each cotyledon formed a mean
of 9.1 buds, so that about 70 shoots could be induced from each seed. The best rooting response (40% rooting) was obtained
by treating the shoots for 8 h with 100 µM naphthalene acetic acid.
Keywords:
conifer, explant, hyperhydricity, micropropagation, organogenesis, pine, provenances.
