8个柳树无性系的观赏价值与适应性研究

选择旱柳、金丝垂柳、柳23、漳河柳、蒿柳、曲6、龙爪柳、竹柳8个具有观赏价值的柳树无性系为试验材料，采用完全随机区组试验设计，观测枝条颜色、分枝角度、叶面积、叶片形状、秋色叶、株高、树姿、冠幅8个指标，基于层次分析法对各无性系的观赏价值及在北京地区的适应性进行评价。结果表明：蒿柳、曲6、龙爪柳、竹柳4种柳树的综合得分值高于旱柳，其中蒿柳的综合评价值最高，表现出较高的观赏性，曲6和龙爪柳的综合评价值仅次于蒿柳，值得推广；漳河柳、金丝垂柳、柳23等无性系的观赏性中等，在园林绿化中可依据不同用途进行选择性运用。除金丝垂柳外，其他柳树无性系的扦插成活率均达80%以上，都较易繁殖；8个柳树无性系的越冬成活率均为100%，在北京地区气候条件下均能顺利越冬。漳河柳、柳23、竹柳、龙爪柳的抗病虫害能力强，总体评价为Ⅰ级；蒿柳、曲6、旱柳的抗病虫害能力较强，评价为Ⅱ级；金丝垂柳的抗病虫害能力最弱，为Ⅲ级。对8个柳树无性系的物候期研究发现，除蒿柳外的其他柳树无性系的物候现象差异不大。蒿柳萌芽最早，花芽亦具有较强的观赏性；1年生枝条就能开花，可增加北京地区早春开花树种；绿期较长，叶片背面有白色绒毛，适宜在北京生长。因此，蒿柳、龙爪柳、曲6、竹柳的观赏性较强，且具有繁殖容易、绿期长、抗病虫害能力强等特性，适合在北京地区推广。

Ornamental Value and Adaptability of 8 Willow Clones

Eight willow species with ornamental value were chosen in this study. Eight indexes, such as plant height, tree gesture, crown breadth, leaf area, leaf shape, with or without autumn-leaf, branch color and branch angle, were observed with complete randomized block design. Based on analytic hierarchy process, the comprehensive ornamental evaluation of the above willows was conducted. Meanwhile, the adaptability of the 8 willows was also evaluated. The result shows that the comprehensive values of 4 willow species, Salix viminalis, S.matsudana Koidz f. tortuosa Rehder, Qu 6 and bamboo willow was higher than S.matsudana. The comprehensive value of S.viminalis was the highest and Qu 6 and S.matsudana Koidz f. tortuosa Rehder take second place, the above 3 willows was worth promoting. The ornamental characteristics of S.matsudana f. lobato-glandulosa, S.x aureo-pendula and Liu 23 were moderate, and they could be applied in use selectively. The survival rates of 7 willows except S.x aureo-pendula were above 80% and they were easy to reproduce. The winter survival rates of the 8 willows were 100% and they can survive in Beijing. The capacity of diseases and insects resistance of S.matsudana f. lobato-glandulosa, Liu 23, bamboo willow and S.matsudana f. tortuosa were strong, S.viminalis, Qu 6 and S.matsudana were moderate, S.x aureo-pendula was weak. The phenological period of 7 willows except S.viminalis had little difference. The sprout of S.viminalis was the earliest and the ornamental characteristics of blossom bud were also strong; one-year-old seedlings of S.viminalis could bloom and increased early spring flowering woody plants; with long green period and white fluff in blade back, S.viminalis was suitable to grow in Beijing. Therefore, four willows, S.viminalis, S.matsudana Koidz f. tortuosa Rehder, Qu 6 and bamboo willow, present fine ornamental values, possess long green strong period, are easy to reproduce and resistance to diseases and insects, so they are suitable to generalize in Beijing area.