2019 journal article
ANATOMICAL, PHYSICAL, AND MECHANICAL PROPERTIES OF TRANSGENIC LOBLOLLY PINE (PINUS TAEDA L.) MODIFIED FOR INCREASED DENSITY
WOOD AND FIBER SCIENCE, 51(2), 173–182.
Traditional breeding methods are often constrained by the reproductive cycles of tree species and the difficulty in achieving significant improvements to complex traits; therefore, genetic manipulation of complex traits such as wood properties has the potential to resolve those issues. The objectives of this study were to analyze MOE, MOR, and the physical and anatomical properties of 2- to 3-yr-old field-grown transgenic Pinus taeda trees modified for increased density. This investigation consisted of a total of 55 sample trees in two separate experiments. Transgenic trees from sets OX41 and OX55, modified for increased density using two variants of the same HAP5 gene, exhibited higher mechanical properties with smaller stem diameter and tracheid lumen diameter than their set of control trees. In addition, set OX55 exhibited increased cell wall thickness. In the second experiment, the transgenic group WVK249, modified for higher density using an unrelated MYB gene, exhibited similar diameter growth and increased cell wall thickness and lower lumen/cell wall ratios but no change in mechanical properties compared with its control.