Somatic Embryogenesis in Picea Glehnii and P. Jezoensis

Abstract

Picea glehnii (Saghalien spruce) is distributed in Hokkaido, the southern Kuril Island, Sakhalin and Mt.Hayachine of Honsyu. Picea jezoensis (Yezo spruce) grows in Hokkaido and Sakhalin while P. jezoensis var. hondoensis (Hondo spruce) occurs only on Honshyu Island (Fig. 1). Picea glehnii becomes 30 to 40 m tall. New-growth twigs have many short reddish brown hair. Picea jezoensis is an evergreen conifer which has straight trunk of 20 to 30 m in height. Its bark is thick and scaly. These species are used for timber, furniture, musical instruments and pulp. For tree breeding program, 277 plus trees of P. glehnii, 112 of P. jezoensis and 20 of P. jezoensis var. hondosensis were selected from Hokkaido and Honsyu. In one example, seed producton from a seed orchard of P. glehnii was 100 g per ha. Sixteen gene preservation forests of P. glehnii and 9 gene preservation forests of P. jezoensis were set in Hokkaido. Tree breeding of these Picea species was done mainly with plus tree selection from natural forests. Cross breeding between P. glehnii and P. jezoensis was also done and hybrid and back-crossed families were made. Genetic variation of glutamate dehydrogenase isozymes of both species was also reported. However, the fact that first fruiting is usually observed only in 30 to 50 year-old trees, indicating that a long time is necessary in the improvement of these species. Somatic embryogenesis can assist in improvement by offering new approaches such as a gene transfer system.