Departamento de Zoología, Universidad de Granada, Granada, Spain.
Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany.
PLoS One. 2018 Dec 12;13(12):e0207553. doi: 10.1371/journal.pone.0207553. eCollection 2018.
Herbivorous mammals and insect pre-dispersal seed predators are two types of herbivores that, despite their functional and morphological differences, tend to severely impact many plant species, highly decreasing their seed production and even imperiling the performance of their offspring through transgenerational effects. However, how they influence offspring resistance to herbivory remains largely unknown. In this study we experimentally examined the effects of ungulates and pre-dispersal seed predators on seed quality as well as on the emergence, survival and resistance to herbivory of the seedlings of a semiarid herb. We found that ungulates reduced seedling recruitment but increased seedling resistance to leaf miners. These effects were probably a consequence of insufficient carbon provisioning in seeds that reduced seed viability and provoked carbon limitation in seedlings. Pre-dispersal seed predators did not influence seedling recruitment, but seedlings from mothers damaged by ungulates and by pre-dispersal seed predators suffered less herbivory by grasshoppers. Remarkably, intra-individual differences in damage by pre-dispersal seed predators affected the rate of damage underwent by seedlings. That is, seedlings derived from fruits attacked by seed predators were more resistant to herbivores than siblings derived from un-attacked fruits in plant populations exposed to ungulates. To our knowledge, this is the first study reporting variation in transgenerational-induced resistance of seedlings from the same maternal plant. This study is a valuable contribution to the understanding of transgenerational effects of multiple herbivores and their implications for a deeper comprehension of the natural systems in which they co-occur.
食草哺乳动物和昆虫预分散种子捕食者是两种类型的食草动物，尽管它们在功能和形态上存在差异，但往往会严重影响许多植物物种，极大地降低它们的种子产量，甚至通过跨代效应危及它们后代的表现。然而，它们如何影响后代对草食性的抵抗力在很大程度上仍然未知。在这项研究中，我们通过实验研究了食草动物和预分散种子捕食者对种子质量的影响，以及对一种半干旱草本植物种子萌发、存活和对草食性抵抗力的影响。我们发现食草动物减少了幼苗的繁殖，但增加了幼苗对叶虫的抵抗力。这些影响可能是由于种子中提供的碳不足，从而降低了种子的活力，并使幼苗受到碳限制。预分散种子捕食者并不影响幼苗的繁殖，但来自被食草动物和预分散种子捕食者破坏的母株的幼苗受到草蜢的侵害较少。值得注意的是，预分散种子捕食者造成的个体内差异会影响幼苗遭受的侵害速度。也就是说，在暴露于食草动物的植物种群中，与来自未受攻击果实的兄弟姐妹相比，来自被种子捕食者攻击过的果实的幼苗对草食动物的抵抗力更强。据我们所知，这是第一个报告同一母株的幼苗跨代诱导抗性变化的研究。这项研究是对多种食草动物跨代效应及其对更深入理解它们共同存在的自然系统的意义的重要贡献。
