Experiment on Planting in Groups with Populus × xiaohei cv‘Chifeng’ Survival and Juvenile Growth of Populus ×euramericana (Dode) Guineir cv.‘Neva’ Cuttings from Stem and Branch of Different Parent Shoots and Planting Spaces Study on the Difference in Expression Profiles of microRNA Among Leaf Organs of Triploid and Diploid Populus×euramericana cl.‘Zhonglin46’ A New Variety of Populus×siomonii ‘Huilin88’ Exogenous Gene Expression on Transgenic Populus×euramericana cv. ‘74/76‘ Carrying Bivalent Insect-Resistant Genes The Relationship between Different Amounts of Irrigation and Changes of Soil Water Content in Populus×xiaozhuanica cv.‘popularis’ Plantation in Arid Area in lnner Mongolia Genetic Analysis ofClonal Growth Traits in Gene-Pool of Black Popular A Study on Distribution of Root System of Populus×euramericana cv. ‘74/76’ Plantation with Ground Drip Irrigation