INFLUENCE OF TAXONOMIC RELATEDNESS AND MEDIUM COMPOSITION ON MERISTEMATIC NODULE AND ADVENTITIOUS SHOOT FORMATION IN 9 PINE SPECIES

Embryos of Pinus echinata Mill., Pinus taeda L., Pinus serotina Michx., Pinus eldarica Medwed., Pinus caribaea Morelet. Pinus oocarpa Scheide, Pinus tecunumanii (Schwd.) Equiluz & Perry, Pinus strobus L., and Pinus radiata D. Don were cultured following the protocol for Pinus radiata to determine if a perpetual meristem culture could be produced. Two subsequent experiments were done that included modifications to the medium's mineral composition, strength (modified LePoivre and Murashige and Skoog at half-strength and full strength), cytokinin concentration (1.0, 2.5, and 5.0 mg/L benzyladenine), and auxin concentration (0 and 0.1 mg/L indolebutyric acid). Pines in subsection Australes performed poorly in culture relative to those species in subsection Oocarpae. Pinus radiata and Pinus eldarica were the only species to produce long-term subculturable meristematic tissue, although shoots were obtained with seven of the species. Half-strength modified LePoivre medium containing 2.5 mg/L benzyladenine but no auxin gave the best results with most species. Significant differences in shoot production were found among Pinus oocarpa provenances.