Cross breeding strategies are very efficient for gaining new and superior genotypes. Ninety-eight new white poplar hybrid clones produced from 12 cross combinations within the Section Leuce Duby were studied using genetic analysis and seedling tests. We exploited the wide variation that exists in this population and found that the differences among diameter at breast height （DBH）, root collar diameter （RCD） and height （H） were statistically extremely significant. The repeatability of clones of these measured traits ranged from 0.947-0.967, which indicated that these traits were strongly controlled by genetic factors. Based on multiple compari- sons, a total of 25 clones showed better performance in growth than the control cultivar. These 25 clones were from six different cross combinations, which can guarantee a larger genetic background for future new clone promotion projects. This study provides a simple overview on these clones and can guide us to carry out subsequent selection plans.
LI BoHANG Xi-bingZHANG You-huiZHANG Zhi-yiLI Shan-wenAN Xin-min
Variation of growth traits of progenies of twenty-three cross combinations in Populus was analysed,and genetic variation among parents was studied by Amplified Fragment Length Polymorphism(AFLP).The results showed that growth traits of progenies and molecular genetic distance(GD) among parents had considerable variation.Correlation and regression analysis between molecular genetic distances among parents and growth traits of progenies indicated that the relationship between GD and growth was linear equation in a certain range(0.024 9～0.368 1),and that the relationship was quadratic parabola equation in a wide range(0.024 9～0.531 4).If the genetic distance among parents in Populus would range from 0.19 to 0.36,the ultimate effect of hybridization could be achieved based on the established relationship between GD and growth.
