Plantlet regeneration from mature zygotic embryos of eastern white pine (Pinus strobus L.)

Abstract

Plants were regenerated from whole embryo explants obtained from eastern white pine (Pinus strobus L.) seeds. Embryos were surgically removed and axenically cultured to induce buds in vitro on a modified Murashige and Skoog medium containing various concentrations of 6-benzylaminopurine. Embryos remained on bud induction medium for 21 days and then were transferred to the same basal medium without 6-benzylaminopurine to promote bud development and subsequent shoot elongation. The medium containing 10 μM 6-benzylaminopurine induced the greatest number of shoots per embryo. Rooting was achieved by direct transfer of the shoots to a non-sterile artificial soil mixture followed by multiple treatments with 15 nM 1-naphthaleneacetic acid. Regenerated seedlings are currently growing under greenhouse conditions.

Plantlet regeneration from mature zygotic embryos and embryonic explants of masson pine (Pinus massoniana Lamb.)

“…BA at 1.0 mg /L in combination with NAA at 0.05 mg /L produced the greatest average number of shoots per embryo (13.4 ± 2.0) among the embryos that produced buds. This figure compares favorably with the average shoot production per culture of 15 shoots per emrbyo reported for P. strobus by Schwarz et al (1988) [4] on MS medium and the 14.7 shoots per cotyledon-hypocotyl explant of P. strobus on MS medium achieved by Kaul (1987) [5]. Most of the adventitious buds were formed directly from the cotyledons of masson pine (Fig 2).…”

“…For conifer propagation, it is known that the most critical factors are kinds of explants, media components and cytokinin treatment [1,2]. To date, the best results have been obtained using mature zygotic embryos and embryonic explants, and BA alone or in combination with NAA has been shown very effective in promoting bud differentiation in most of the Pinus species [2][3][4][5].…”

Plantlet multiplication from white pine (Pinus strobus L.) embryos in vitro: bud induction and rooting

“…Over all media, maximum shoot production occurred at the 20/~M concentration. This is twice the concentration used by Schwarz et al (1988) and by Kaul (1987) and almost 5 times that used by Flinn et al (1986). Regardless of media, the 20/zM concentration gave shoot numbers substantially higher than the 15 shoots per embryo reported a Schwarz et al (1988) on MS medium and the 14.7 shoots per cotyledon/hypocotyl explant on MS medium achieved by Kaul (1987).…”

“…There have been reports of bud and shoot formation from white pine embryo tissues in culture (Webb et al 1988;Schwarz et al 1988;Kaul 1987;Flinn et al 1986;Minocha 1980) and three reports of root formation on in vitro derived shoots (Webb et al 1988;Schwarz et al 1988;Kaul 1987). Flinn et al (1986) and Webb et al (1988) reported the effects of BA concentrations and duration, orientation and source of explant, media concentration, and other factors on caulogenesis from whole embryos.…”

“…Flinn et al (1986) and Webb et al (1988) reported the effects of BA concentrations and duration, orientation and source of explant, media concentration, and other factors on caulogenesis from whole embryos. Kaul (1987); Schwarz et al (1988) and Webb et al (1988) reported plantlet production from seedling parts and embryos, and reported results of different rooting procedures. These procedures varied from commercial rooting powders to aseptic auxin pulse treatments to rooting under nonsterile conditions with auxin treatments.…”