Establishment of an Efficient Regeneration System of Populus×euramericana cl. ‘Bofeng 1’ The Impact of Poplar Diameter Characteristics on Disease Index of Canker Absorption and Accumulation of Heavy Metal from Soil by Leaves of Populus×euramericana cv. ‘Neva’Plantation PRELiMINARY STUDlES ON RADlAL VARlATION PATTERNS OF WOOD PROPERTIES WITHIN TREES IV.STUDIES ON THE RADIAL VARIATION PATTERNSOF WOOD DENSITY IN POPULUS×EURAMERICANA CLONES A PRIMARY STUDY ON THE RADIAL VARIATION PATTERNS OF WOOD PROPERTIES WITHIN TREES V.THE RADIAL VARIATION PATTERNS AND ITS VARIATION OF WOOD FIBRE LENGTH OF 15 CLONES OF POPULUS×EURAMERICHANA Salt tolerance of transgenic poplar by the introduction of AtNHX1 gene