关键词: 白桦, 叶色

Abstract: ‘Zhaoxia 2’is a BpGLK1 suppressive expression transgenic line by Betula platyphylla as the receptor. The expression level of BpGLK1 gene and the content of chlorophyll in leaves were decreased in the cultivar.‘Zhaoxia 2’is a deciduous tree，its trunk bark is grey white and stratified exfoliation，and its branches exhibit reddish brown. The leaves are papery and wide ovate，with the color of yellow green in summer and golden yellow in autumn. The leaf apex is acuminate，the base of the leaf is heart-shaped，and the edge of the leaf is blunt toothed without leaf crack. There are 7–8 primary lateral veins on the upper and lower surfaces of leaves.

Key words: birch, leaf color