A Tissue Culture System for Mature Trees Using Secondary Wood Growth as Explant Material

Regeneration of southern pines through tissue culture has proven difficult when using explant material from adult trees. One of the major stumbling blocks in successfully culturing long-lived woody species is rejuvenation. Ontogenetically young secondary wood growth taken near the base of the tree will potentially display juvenile-like culture responses. A sterilized increment borer was used to collect samples of secondary wood growth from trees at least 40 years in age. Samples were taken from four southern pine species: longleaf pine (Pinus palustris Mill.), slash pine (P. elliottii Englem.), loblolly pine (P. taeda L.), and shortleaf pine (P. echinata Mill.). Longleaf and slash pines were more amenable to culture than loblolly and shortleaf pines. Increment cores were sectioned into disks which were placed in liquid medium. After 6 weeks, disks were transferred to solid medium. A high percentage of disks developed callus. In slash and longleaf pines, cultures were produced which grew well and could be maintained for many subcultures. Some of these cultures exhibited chloroplast development, when moved to light. In some cases, the green callus developed an embryogenic appearance.

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Author(s): E. N. Hiatt, Robert M. Allen

Publication: Tree Improvement and Genetics - Southern Forest Tree Improvement Conference - 1991

Section: General Session: Breeding and Propagation