Abstract
In the Northeastern region of Fukuoka prefecture, local hinoki (Chamaecyparis obtusa) was called ‘Keichiku Hinoki’ and it has been established as a brand. In a questionnaire survey, many answers including those by foresters and lumbermen pointed out red-tinged heartwood as a major characteristic of Keichiku Hinoki. However, current Keichiku Hinoki timbers showed a great variation in 3 heartwood color indices (Lightness, hue and saturation), which provided no clear distinction of Keichiku Hinoki-specific heartwood color. We tried to develop some cultivars stably expressing specific heartwood color. A survey for heartwood color was conducted, where local citizens selected as suitable Keichiku Hinoki timbers from 10 exhibited timbers according to their preferences. The top 4 timbers were significantly different from others in any one of the heartwood color indices, whereas there were no significant differences among them in all indices. Thus, heartwood colors of the top 4 timbers were distinguished from the others. Hence, their color indices were used for selection of proto-cultivars. Our selection members including local forest cooperative staffs preliminarily selected 8 candidates from progenies of ‘Buzen-2’ that was solely selected as the plus tree from Keichiku region in a local progeny test plantation. One individual showed no significant differences from the top 4 timbers in all of the heartwood color indices, and it did not have any remarkable defects in wood properties. We finally selected it and succeeded in clonal propagation by cutting.
