Department of Biology, Stanford University, Stanford, California 94305-5020 USA.
Am J Bot. 2009 Jul;96(7):1255-61. doi: 10.3732/ajb.0800297. Epub 2009 May 28.
Tolerance, the capacity of plants to withstand attack by animals, as opposed to resistance, has been poorly examined in the context of seed predation. We investigated the role that the seed mass of the large-seeded endemic tree Aesculus californica plays as a tolerance trait to rodent attack by comparing, under greenhouse conditions, patterns of germination, and subsequent seedling growth, of seeds with a wide range of natural damage. Germination percentage was reduced by 50% and time to germination by 64% in attacked compared to intact seeds, and germination probability was negatively correlated with damage. Seedlings that emerged from intact seeds were taller and bore more leaves than those from damaged seeds. This species' large seed mass favors tolerance to damage because heavily damaged seeds are able to germinate and produce seedlings. This finding is significant given that seeds of this species are known to contain chemical compounds toxic to vertebrates, a resistance trait. We posit that this combination of tolerance and resistance traits might be a particularly effective antipredation strategy when seeds are exposed to a variety of vertebrate predators.
耐受性是指植物承受动物攻击的能力，与抗性相反，在种子捕食的背景下，耐受性一直未得到充分研究。我们通过比较具有广泛自然损伤的种子在温室条件下的发芽模式和随后的幼苗生长情况，研究了大粒特有树加州七叶树的种子质量作为对啮齿动物攻击的耐受性特征的作用。与完整种子相比，受损种子的发芽率降低了 50%，发芽时间延长了 64%，且发芽概率与损伤呈负相关。从完整种子中萌发的幼苗比从受损种子中萌发的幼苗更高，叶片更多。由于该物种的种子已知含有对脊椎动物有毒的化合物，是一种抗性特征，因此这种大粒种子有利于耐受损伤。我们假设，当种子暴露于各种脊椎动物捕食者时，这种耐受性和抗性特征的组合可能是一种特别有效的抗捕食策略。
