【摘要】 为了了解主要环境因子对藿香蓟表型可塑性的影响,从藿香蓟(Ageratum conyzoides)生物学特性揭示其入侵成因,比较了遮阴、土壤碳氮比和灌溉强度对藿香蓟在形态以及存活和繁殖的影响。结果表明:在全光照或施氮条件下,藿香蓟的总鲜重最高;相对于全光照,低密度遮阴时,藿香蓟通过增大比叶面积,减小根冠比,增加高生长量来维持总鲜重、存活率不变;低密度遮阴虽延迟了藿香蓟开花时间,但却提高了开花数量;高密度遮阴使藿香蓟的比叶面积、根冠比和日均增高量都相对于全光照组下降,整体上造成藿香蓟不开花,且总鲜重和存活率降低;向基质施加尿素,可以增加藿香蓟的比叶面积,同时促使植物降低根冠比;灌溉强度对藿香蓟各指标影响较小,相对于对照组,灌溉量为本地当月平均降雨量的40%时,藿香蓟的日均增高量下降。总的来说,藿香蓟具有较强的表型可塑性和竞争力。更多还原

【Abstract】 In order to understand the effects of main environmental factors on phenotypic plasticity of Ageratum conyzoides—an alien species, and to reveal its invasion mechanism, the effects of different shade, soil carbon and nitrogen ratio and irrigation intensity on the morphology, survival and reproduction of A. cony-zoides were compared. The results showed that the total fresh weight of A. conyzoides was the highest under the condition of full illumination or nitrogen application; A. conyzoides did not reduce the total fresh weight and survival rate by increasing the specific leaf area and reducing the root crown ratio under the condition of low density shading; low density shading delayed the flowering time of A. conyzoides but increased the number of flowers; compared with the plants in full light group, the specific leaf area, the root to crown ratio, the average daily increment, the total fresh weight and survival rate of A. conyzoides in high density shading(98% shading) group were decreased; applying urea can increase the specific leaf area of A. conyzoides, and promote plant to reduce root shoot ratio; compared with the control group,when the irrigation volume was 40% of the local average monthly rainfall, the average daily increment decreased significantly. In general, A. conyzoides has strong phenotypic plasticity and competitiveness.更多还原