同质园背景下榕属植物胶乳生理生态功能探讨

About 10% of all angiosperms plants exude latex, most of them are tropcial plants. The function of plant latex remains controversial. Many researches suggest that plants latex plays important role in defense against herbivory feeding, and interacts with other defensive strategies. However, some study approve that latex did not significantly influent the feeding of herbivory insects and the latex has been believed to contribute to nutrition metabolism and maintaining water balance of plant. Based on previous research, we hypothesis that the main function of plant latex should be maintaining water balance of plant against water stress. The defensive function should only be a 'by-product' of latex during the long process of coevolution with herbivory insects. Try to test our hypothesis, we choose 40 Ficus species with different life form which are planted in the figs garden of XTBG. Because epiphytic plants suffer water stress more intensly than non-epiphytic plants, by common garden approach, we will compare the production and physicochemical property of Ficus latex between different seasons. We try to understand the interaction of latex and other defensive characteristics and the influence of washing-latex treatment on the feeding of herbivory insects. Furthermore, we also try to understand the physiological and ecological function of Ficus latex by eliminating the effect of phylogenetic signal on plants' trait by phylogenetic approach.

植物界中约有10%的被子植物能够分泌胶乳，且主要分布在热带地区。有关植物胶乳的生态功能尚无肯定的结论。大量研究认为胶乳的主要功能是对抗昆虫取食，能够与其他防御策略共同作用；但亦有研究认为胶乳与昆虫取食程度无显著相关性，其功能主要为参与营养代谢和维持水分平衡等。根据以往的研究，我们提出假说认为胶乳的主要功能是维持植物的水分平衡、帮助植物忍耐水份胁迫，而防御昆虫取食的功能仅是含胶乳植物与昆虫长期进化产生的"副产品"。为验证我们的假说，拟选择在西双版纳热带植物园榕树园种植的具有不同生活型的40种榕属植物为研究对象，在同质园条件下，由于在旱季附生榕树较地生种类受更强烈的水份胁迫，通过比较不同季节榕属植物胶乳产量及理化指标变化、胶乳与其它防御性状之间相互关系、胶乳去除对不同榕树受昆虫取食程度的差异，结合系统分析方法去除系统关系对功能性状的影响，进而揭示榕属植物胶乳的生理生态功能。