Research and project activities for breeding of Cryptomeria japonica D. Don in Japan

Breeding of sugi (Cryptomeria japonica) started with the selection of first generation plus-trees in the 1950s in Japan. The initial aim of the breeding program was to improve growth performance, and the aim has been extended to tolerance to adverse meteorological conditions, amelioration of wood properties, mitigation of pollinosis, and adaptation to climate change. These changes have arisen in response to shifts in social demands from timber production to management of diverse forest functions over time. Currently, the focus of C. japonica breeding is focusing on the selection and deployment of second-generation plus-tree clones and establishment of breeding populations for the third-generation plus-trees. In this review, these activities and achievements are described, and prospects of the future breeding initiatives, including the feasibility of breeding for climate change, are discussed.