GENETIC AND PHYSICAL MAPPING IN HYBRID POPLAR OF CRITICAL-TO-QUALITY FACTORS FOR PULP AND PAPERMAKING PROCESSES.

¹ Paprican, 3800 Wesbrook Mall, Vancouver, B.C., V6S 2L9, Canada

Hybrid poplars are well-suited to genetic mapping studies as they are amenable to interspecies crosses, progeny grow rapidly, and they have a relatively small genome. This implies that the identification and manipulation of genetic control elements in poplars will be much easier than in rival fast-growing species such as eucalyptus. Such genes can be used to both rapidly and easily identify superior clonal material in natural populations and to screen such material for plantation establishment. Additionally, knowledge of the genetic structure of superior clones will facilitate the development of tree ideotypes for specific end-product applications. In a previous study on a genetically well-characterized three-generation family of hybrid poplars, this potential was assessed. Quantitative trait loci (QTL – genomic regions containing genes involved in the control of continuously variable traits) for wood and fibre quality traits were determined. As an extension of this study, additional phenotypic information has been gathered for the same family grown at three sites. In this study, the industrially relevant traits examined were: fibre coarseness, fibre yield, pulp properties, kraft pulping, lignin content, wood extractive compounds and calcium salt accumulation. In conjunction with information garnered from the Poplar Genome Project, preliminary physical characterization of the QTL regions is now under way.