Development of micro-propagation in bigleaf maple (Acer macrophyllum) and screening for early markers preceding figured wood formation

Some bigleaf maple (Acer macrophyllum) trees develop defects during wood formation that result in attractive ‘wavy figure’ patterns in the wood. This wood commands a high price and is used primarily for making musical instruments and decorative products. While the underlying causes of these defects are unknown, the large extent and homogeneity of the defects in many individuals suggest an underlying genetic basis. Typically, available living material from cut trees is limited. To propagate trees from a limited amount of source material, we have developed an in vitro procedure that combines (i) cutting of shoot apices to break apical dominance with (ii) hormone treatment to induce shoot multiplication from lateral buds. This procedure can be repeated as needed for propagation, followed by root induction to generate bigleaf maple plants. It is not assured that clones of figured wood trees will develop figure patterns, and harvested trees typically do not show figure patterns in their 10–15 first growth rings. Hence, we have begun searching for potential early anatomical and/or chemical differences between young clones from non-figured and figured trees. Pyrolysis Molecular Beam Mass Spectroscopy analysis suggests that the content of two unknown cell wall components, m/z_69 and m/z_298, differ between non-figured wood and figured wood tree clones. The basis for this difference remains unknown. Taken together, we have developed the first micro-propagation procedure for bigleaf maple and also identified potential markers of early chemical differences between tested clones of figured and non-figured wood trees.