Micropropagation of mature Calabrian pine (Pinus brutia Ten.) from fascicular buds

Abstract

Dormant meristems of fascicles explanted from 10-year-old, field-grown trees of Pinus brutia Ten. were cultured in vitro. Browning of cultured fascicles was reduced by including 150 mg l(-1) sodium diethyldithiocarbamate (SDD) in a cytokinin-containing medium. The stage of development of fascicles when placed in culture affected both shoot-bud production and the degree of browning. Only fascicles at an advanced stage of development had a high rate of shoot-bud production. Fascicles cultured for 6 weeks in initiation medium containing 150 mg l(-1) SDD and then for 4 weeks in initiation medium containing 1 mg l(-1) insoluble polyvinylpolypyrrolidone showed the highest rate (23%) of shoot-bud development and the lowest rate (15%) of browning. Elongation of activated shoot buds was considerably enhanced by reducing the concentration of cytokinin in the culture medium. Only shoots >/= 20 mm in height were capable of producing further crops of buds and shoots. When treated with a combination of auxin and cytokinin, only 16% of the elongated shoots produced roots.

Elongation, rooting and acclimatization of micropropagated shoots from mature material of hybrid larch

“…Cytokinins commonly stimulate shoot proliferation and inhibit their elongation; a primary medium can be used to stimulate bud multiplication and later, they can be transferred to a secondary medium with other combinations of plant growth regulators (Huetteman & Preece, 1993). Elongation of short shoot buds from explants of 10-year-old Pinus brutia trees (Abdullah et al, 1987) and of adventitious buds from seedling explants of Picea abies (Ewald & Stiss, 1993) was also enhanced by reducing the concentration of cytokinin in the culture medium. In hybrid larch, a first and second passage on a medium containing 0.5 ~tM BA induced stem elongation in respectively 36% and 33% of the shoots.…”

“…Maturation, a complex phenomenon, is the major problem preventing a wider application of tissue culture technology among woody species (Pierik, 1990). Despite this, shoot formation and elongation, using explants from mature conifers, have been reported in Thuja (Coleman & Thorpe, 1977), Pinus (Gupta & Durzan, 1985;Abdullah et al, 1987) and Picea (Mac An t-Saoir et al, 1991). However, rooting, acclimatization and successful field trials are restricted to a few species including: Sequoia sempervirens (Boulay, 1987), Pinus radiata (Horgan & Holland,t 989), Pinus pinaster (Monteuuis & Dumas, 1992) and Pseudotsuga menziesii (Pullman & Timmis, 1992).…”

Seasonal changes in explant viability and contamination of tissue cultures from mature Scots pine

“…However, there are only a few reports of propagation using tissues from mature conifers [4,8,1]. Among Pinus species, the Scots pine (Pinus sylvestris) appears to be especially difficult to handle in cultures, and attempts to propagate it vegetatively by traditional tissue culture methods have been only partly successful [21,5,28,24].…”

In vitro regeneration of Pinus brutia Ten. var. eldarica (Medw.) through organogenesis

“…Organogenesis in P. brutia has already been achieved (Abdullah et al, 1984(Abdullah et al, , 1986(Abdullah et al, , 1987. However, those protocols reported a low number of shoots per explant, and the percentage of fascicles that formed shoot buds was low.…”