Rapid micropropagation of Calabrian pine from primary and secondary buds on shoot explants

Abstract

Axillary shoot production was achieved in 6 weeks using excised shoot explants of Pinusbrutia Ten. on a modified Schenk and Hildebrandt medium containing cytokinin. Primary shoots arose from existing axillary buds and secondary buds arose from bases of the primary shoots. Their production could be increased by regulating the cytokinin level and by surgical removal of apical buds from the cultured explants. However, the best performance was achieved with a low level of 6-benzylaminopurine (3 × 10−6 M) or a mixture of 6-benzylaminopurine and kinetin (10−6 M of each). Subsequent transfer to a cytokinin-free medium resulted on average in the production of 43 shoots per cultured explant and up to 67 shoots per clone within 12 weeks. When the primary shoots, which had already produced one crop of secondary shoots, were maintained under conditions favourable for shoot production, a doubling in number was obtained within 4–6 weeks. To encourage further elongation, newly formed shoots were incubated for 2 weeks on a cytokinin-free medium to which 1% activated charcoal was added. The time taken with this method was much shorter than with other published methods and is, therefore, likely to be important for the vegetative propagation and multiplication of selected seedlings of this species.

Plantlet regeneration from fascicular buds of seedling shoot apices of Pinus roxburghii Sarg

“…Superiority of BA for shoot induction may be attributed to the ability of plant tissues to metabolize BA more readily than other synthetic plant growth regulators or to the ability of BA to induce production of natural hormones such as zeatin within the tissue (Zaerr and Mapes 1982). Similar promotory effect of BA in inducing multiple shoots has been reported in several other reports on variety of pine species (Gupta and Durzan 1985, Abdullah et al 1986, Lapp et al 1996, Kalia et al 2001. The concentration of BA used in the medium significantly influenced multiple bud formation.…”

“…Plant regeneration from axillary or quiscent meristems is a widely used method as it results in formation of genetically identical individuals. It is known that plants regenerated from axillary buds and shoot tips are genetically stable and free from somaclonal variations (Abdullah et al 1986) as in pines, buds generally arise from quiescent meristems located adaxial to the juvenile needles and in the axil of cotyledons (David 1982).…”

MICROPROPAGAÇÃO DE <i>Pinus tecunumanii</i>

“…Micropropagation by apical shoots is the most usual method for mass production of superior clones by tissue culture, and it is advantageous because clones with known characteristics can be produced on a large scale (HARTMANN et al, 2011). Plants from regenerated shoot tips or axillary buds usually show higher genetic stability and have a lower risk of somaclonal variation when compared to plants regenerated by organogenesis (ABDULLAH et al, 1986).…”

Micropropagation Via Axillary Bud Proliferation from Seedlings and Juvenile Shoots ofPinus patulaSchiedeetDeppe

“…In some Pinus spp., such shoots have been obtained in vitro from seedling Pinus patula seedlings were grown in composted explants (e.g. Horgan and Aitken, 1981;Mudge, pine bark and housed in a nursery tunnel which was 1986; Abdullah et al, 1986Abdullah et al, , 1989Zel et al, 1988; covered with Patilux plastic and surrounded with Baxter et al, 1989;Austin Burns et al, 1991;Jang 55 % windbreaking shade-cloth. The seedlings were and Tainter, 1991), juvenile/ fascicle shoots (e.g.…”