EFFECT OF PARTIALLY CAD-DEFICIENT LOBLOLLY PINE (CAD-NL HETEROZYGOTES) ON PULPING AND PAPER PROPERTIES

摘要

One of the best loblolly pine parent trees in the tree improvement program at North Carolina State University is selection 7～56. It produces progeny that are extremely fast growing with excellent quality traits. It is also a carrier of a rare gene (cad-nl) that results in a deficiency in the enzyme cinnamyl alcohol dehydrogenase, which catalyzes the last step in the biosynthesis of coniferyl alcohol. Breeding with 7～56 produces three types of trees: Cad/Cad (Wild), Cad/cad-nl (cad-nl hetrozygote) and (cad-nl/cad-nl (cad-nl homozygote). This paper evaluates the impact that this gene has on the pulping and paper making characteristics by evaluating the Wild and cad-nl hetrozygote (CAD)trees. No difference in pulping rate or yield was measured between the CAD and Wild samples. There was also no difference in bleachabilty between CAD and wild trees. Strength properties were compared for bleached and linerboard grade pulps. No significant difference in tear-tensile relationship between CAd and Wild was measured. As a result, plantations can take advantage of the higher growth rates with 7～56 hetrozygote CAD trees without any significant effects on pulping or strength properties.