Abstract:

In order to supply necessary scientific bases and reference for breeding, genetic variation regularities in growth and wood properties of eucalyptus during hybrid breeding process were investigated. Variation and genetic parameters of major growth and wood properties were studied with F₁ of E. urophylla×E. grandis as materials. The results are as follows. (1) Tree height, DBH and dry timber yield of F₁ are mainly genetically controlled by father trees. (2) Wood basic density is controlled genetically by both father and mother, and their interaction too. (3) Fiber length and microfibril angle are mainly controlled genetically by mother trees; whereas tangential diameter of pores, cell-wall percentage of wood, wood fiber percentage and 1%NaOH extractives are mainly controlled by father trees genetically, and the ratio of fiber length to width too, but to a lesser extent; Percentage of vessel is controlled genetically by both father and mother trees; (4) Phenotypic variation in the ratio of cell wall thickness to fiber lumen diameter is mainly affected by environmental factors, father and mother and their interaction all show no significant genetic control on it.

Key words: E.urophylla×, E.grandis, Full-sib progenies, Growth traits, Wood properties, Genetic variation