Table S2 from Evolutionary ecology of climacteric and non-climacteric fruits

Fleshy fruits can be divided between climacteric (CL, showing a typical rise in respiration and ethylene production with ripening after harvest) and non-climacteric (NC, showing no rise). However, despite the importance of the CL/NC traits in horticulture and the fruit industry, the evolutionary significance of the distinction remains untested. In this study, we tested the hypothesis that NC fruits, which ripen only on the plant, are adapted to tree dispersers (feeding in the tree), and CL fruits, which ripen after falling from the plant, are adapted to ground dispersers. A literature review of 276 reports of 80 edible fruits found a strong correlation between CL/NC traits and the type of seed disperser: fruits dispersed by tree dispersers are more likely to be NC, and those dispersed by ground dispersers are more likely to be CL. NC fruits are more likely to have red–black skin and smaller seeds (preferred by birds), and CL fruits to have green–brownish skin and larger seeds (preferred by large mammals). These results suggest that the CL/NC traits have an important but overlooked seed dispersal function, and CL fruits may have an adaptive advantage in reducing ineffective frugivory by tree dispersers by falling before ripening.

肉质果实可分为跃变型（climacteric, CL）与非跃变型（non-climacteric, NC）两类：其中跃变型果实于采收后成熟时会出现呼吸速率与乙烯生成量的典型峰值上升，而非跃变型果实则无此类特征性变化。尽管跃变与非跃变性状在园艺学及果品产业中至关重要，但该性状分化的进化意义迄今仍未得到验证。本研究针对下述假说展开验证：仅在植株上完成成熟过程的非跃变型果实，其演化适配对象为树栖种子传播者（即于树上取食的传播者）；而从植株脱落后才成熟的跃变型果实，则适配于地面种子传播者。通过对80种可食用果实的276篇相关报道进行文献综述，本研究发现跃变/非跃变性状与种子传播者类型之间存在显著相关性：由树栖传播者扩散的果实更大概率为非跃变型，而由地面传播者扩散的果实则更大概率为跃变型。非跃变型果实多具备红黑色果皮与较小的种子（更受鸟类青睐），跃变型果实则多带有绿褐色果皮与较大的种子（更受大型哺乳动物青睐）。上述结果表明，跃变与非跃变性状具备一项长期被忽视的重要种子传播功能；跃变型果实可通过在成熟前脱落，降低树栖传播者带来的无效取食风险，从而获得演化适应性优势。