资源共享的方向性对入侵植物海榕菜生理整合的影响

• 作 者: Rubén Portela Rodolfo Barreiro Sergio R.Roiloa
• 出 处: 植物生态学报（英文版）
• 发表日期: 2021年5期
• 关键词: biomass partitioning Carpobrotus clonal growth division of labor physiological i

与植物克隆生长相关的一个关键性状是生理整合能力,它允许在一个克隆内相连接的分株之间共享资源.资源传输遵循源-汇关系:从生长在资源丰富斑块上的分株到生长在贫瘠斑块上的分株.然而,一些实验结果表明,向顶运输(从后端到前端)通常超过基部运输(从前端到后端).在本研究中,我们旨在确定入侵植物海榕菜(Carpobrotus edtvlis)生理整合模块的资源运输方向.我们开展了两个模拟实验,研究了在不同位置(后端、中部、前端)的不同营养水平对海榕菜连接和断开克隆系统的影响.比较了分株生物量分配模式和最终生物量,以阐明生理整合的作用是否受资源运输方向性的影响.研究结果表明,海榕菜资源的向顶运输是普遍存在的,其发育分工是后端分株专注于获取土壤资源,前端分株专注于地上生长.虽然在最严酷的生长条件下的前端分株所获得的效益最高,但这种生物量分配模式不受后端或前端分株生长的营养条件的影响.这种发育程序化的分工被认为可以促进海榕菜的横向生长,从而对这种入侵物种的扩展具有重要意义.“,”Aims One of the key traits associated with clonal growth in plants is the capacity for physiological integration,which allows resource sharing between connected ramets within a clonal system.Resource transport is expected to occur following a source-sink relationship:from ramets established in rich patches to ramets growing in poor patches.However,some experiments have shown that acropetal transport(from basal to apical modules)usually exceeds basipetal transport(from apical to basal ramets).In this study,we aimed to determine the resource transport directionality in physiologically integrated modules of the invader Carpobrotus edulis.Methods We conducted two manipulative experiments under common garden conditions that studied the effect of different nutrient levels located at different positions(basal,medial and apical)on connected and disconnected clonal systems of C.edulis.We compared the biomass partitioning patterns and final biomass of ramets to elucidate whether the effect of physiological integration is affected by the directionality of the resource transport.Important Findings Results indicate a prevalent acropetal transport of resources in C.edulis,with a developmentally programmed division of labor where basal ramets were specialized in obtaining soil-based resources and apical ramets specialized in aboveground growth.This biomass partitioning pattern was not affected by the nutrient conditions in which basal or apical ramets were growing,although the highest benefit was achieved by apical ramets growing under the most stressed conditions.This developmental ly programmed division of labor is expected to increase the lateral growth of C.edulis,and therefore could have meaningful implications for the expansion of this invasive species.