Abies concolor (white fir) is one of the many conifers often planted as an ornamental tree. Like so many other conifers, Abies is difficult to vegetatively propagate. Recent successes in using the techniques of tissue culture as a means of vegetatively propagating plants prompted the present study of applying these techniques to Abies.A review of the literature indicated that no conifer had ever been grown into plantlets by using the techniques of tissue culture. Only a very few reports exist for cellular differentiation although nearly thirty species of conifers have been grown in-vitro as callus.The review of literature also indicated that a variety of growth regulators, supplements and conditions of growth were utilized in promoting differentiation and the development of plants from callus. Since no consistent patterns emerge as guidelines for achieving differentiation, a proposal was made to test the effects of several growth regulators on callus tissue of Abies in hopes of causing differentiation and organogenesis.Terminal stem sections from the lower branches of a mature tree of Abies concolor were removed, sterilized and and placed on experimental solid media containing mineral salts, growth regulators and organic supplements. Growth of a callus occurred as a cream-colored friable mass on several of the media. When examined, however, the growth was found to consist of only parenchymatous cells. When transferred to a medium (G7) containing coconut milk, casein hydrolysate and 2 mg/l kinetin, compact, hemispherical nodules developed over a period of six weeks.A number of these nodules were fixed, embedded,'sectioned and stained with safranin and fast green. These were examined with a microscope and comparative photographs between this type of growth and the friable callus were made.Sections of the nodules showed a more compact arrangement of cells and an incomplete ring of growth consisting of cells arranged in radial files as if produced by a cambium. The center of the incomplete ring contained parenchymatous cells primarily, but scattered tracheid-like cells with bordered pits were also noted. Photographs of the well organized incomplete ring of growth and the tracheid-like cells were made.It can be concluded that differentiation of Abies concolor callus did occur on the G7 medium and that this represents a positive step toward organogenesis using the techniques of tissue culture.
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/180512 |
| Date | January 1972 |
| Creators | Schnurbusch, Donald Joseph |
| Contributors | Eiser, Arthur L. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | viii, 86 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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