Genetic variations and primary selections of main wood properties among Michelia macclurei families

Objective  To understand genetic variation characteristics and provide bases for superior families selection and germplasm resources reasonable exploitation and utilization in Michelia macclurei based on estimation of wood property genetic parameters among families and correlation analyses between wood properties and growth traits.

Method  Genetic variation characteristics of wood basic density, fiber length, fiber width and fiber length/width ratio were analyzed using 100 families in M. macclurei provenance family forest.

Result  Timber characteristics among families existed significant differences (P<0.01) and had great selection potentials. The variation ranges of wood basic density, fiber length, fiber width and fiber length/width ratio among different provenances were 0.38-0.53 g·cm^–3、0.65-0.91 mm、23.20-28.87 μm and 22.92-38.66 respectively, with mean values of 0.48 g·cm^–3、0.79 mm、25.88 μm and 30.74 respectively. The genotypic and phentypic correlation analyses showed that the wood properties of each family were significantly correlated with the growth traits, except no significant genotypic correlation between fiber length and diameter at breast height or volume. The correlation between wood density and fiber length was not significant, and these two traits could be selected independently. The individual heritability of wood basic density and fiber length were 0.374 and 0.372 respectively, both under highly genetic control. The individual heritability of fiber width and fiber length/width ratio were 0.166 and 0.231 respectively, both under moderate genetic control.

Conclusion  The superior wood property families are selected through intense and moderate selection methods. In consideration of actual production and following breeding, the moderate selection is more suitable for the present experimental forest. This study selected 52 superior wood basic density families, 44 superior fiber length families, and 23 shared families. These 23 families are more suitable as suporior materials for combined primary selection.