Ågren J
Department of Forest Site Research, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden.
Oecologia. 1987 May;72(2):161-169. doi: 10.1007/BF00379262.
Shoot development and damage by herbivores and pathogens to male, female and non-floral ramets of the dioecious, perennial herb Rubus chamaemorus were studied in the field during three consecutive years. Leaves on male ramets were usually consumed more by herbivores and attacked more by fungi than were leaves on female ramets. Male ramets unfolded their leaves later than did female ramets. In 1983, when the level of herbivory was comparatively high, ramets that were fully developed in early June were more damaged by herbivores than were ramets that unfolded their leaves later. Non-floral ramets usually showed intermediate levels of damage compared to male and female flowering ramets.Defoliation caused a greater increase in ramet mortality among females than among males in a field experiment. It is suggested that the different reproductive roles of males and females differently constrain the evolution of defense against herbivores and pathogens in dioecious plants. This may result in intersexual differences both in palatability to herbivores and susceptibility to pathogens.
连续三年在野外研究了雌雄异株的多年生草本植物兴安悬钩子的雄株、雌株和非花分株的枝条发育情况，以及食草动物和病原体对它们的损害。与雌株的叶子相比，雄株的叶子通常被食草动物啃食得更多，受到真菌侵害的情况也更多。雄株比雌株展开叶子的时间更晚。1983年，当食草动物的侵害程度相对较高时，6月初就完全发育的分株比那些叶子展开较晚的分株受到食草动物的损害更大。与雄花和雌花分株相比，非花分株通常表现出中等程度的损害。在田间试验中，落叶导致雌株分株死亡率的增加幅度大于雄株。研究表明，雄株和雌株不同的繁殖角色对雌雄异株植物防御食草动物和病原体的进化产生了不同的限制。这可能导致在对食草动物的适口性和对病原体的易感性方面出现两性差异。
