0000000000305648
AUTHOR
M. P. Gomez
Axillary shoot proliferation in cultures of explants from mature Juniperus oxycedrus trees.
We developed procedures for the micropropagation of Juniperus oxycedrus L. using shoot apices or nodal segments from mature plants. Of the media and explants examined, best culture establishment was obtained with shoot apices cultured on modified Schenk and Hildebrandt medium (SH medium) without growth regulators; however, shoot multiplication was only achieved when shoot apices isolated from shoots grown on SH medium without growth regulators were subcultured on SH medium containing 0.5 micro M benzyladenine. None of the auxins and methods tested for root induction provided satisfactory results.
Factors controlling adventitious bud induction and plant regeneration in matureJuniperus oxycedrus leaves cultured in vitro
The morphogenetic capacity of matureJuniperus oxycedrus L. leaves cultured in vitro has been studied, noting nutritive, hormonal, and environmental factors inducing differentiation and development of adventitious shoots. Bud primordia formed directly from the leaves. Highest bud differentiation rates were obtained when the explants were cultured for at least 21 days on a modified Schenk and Hildebrandt solidified medium containing 0.5 μM benzyladenine under a 16-h photoperiod. Maximum bud development and elongation was achieved on cytokinin-free medium containing 4% (wt/vol) sucrose and 0.05% (wt/vol) activated charcoal. Regenerated shoots were excised and induced to root on media with auxi…
Morphogenesis in leaf and single-cell cultures of mature Juniperus oxycedrus
Single cells were mechanically isolated from leaf-derived callus of mature Juniperus oxycedrus L. These cells divided and gave rise to callus when plated on medium containing growth regulators. Best plating efficiency was obtained on a modified Schenk and Hildebrandt medium supplemented with 0.6 micro M 2,4-dichlorophenoxyacetic acid and 100 mg l(-1) casein hydrolyzate. Although single-cell-derived callus showed poor morphogenic potential, both adventitious shoots and embryogenic tissues differentiated from the callus. We also achieved induction of somatic embryogenesis in leaf explants of mature J. oxycedrus trees cultured in the presence of 6.0 or 10.0 micro M 2,4-dichlorophenoxyacetic ac…