Abstract Aims Transgenerational effects in plants incur opposing effects on the adaptation to predictable vs. unpredictable environments. While seed-dimorphic plants can produce dimorphic offspring with different adaptive strategies, it remains unclear whether the transgenerational effects and seed dimorphism may interact to dictate offspring adaptation. This study aimed to explore whether and how seed-dimorphic maternal plants impart different transgenerational effects to dimorphic offspring. Methods Synedrella nodiflora was chosen as a study species, which is adaptive to a wide soil water gradient and produces two distinctive types of seeds (light disc vs. heavy ray seeds). In a greenhouse, S. nodiflora was grown for two generations under drought stress to test whether the transgenerational effects on offspring performance and mortality depend on maternal or offspring seed morph. The potential regulatory mechanisms were explored by measuring seed provisioning and chemical regulators of maternal plants and related reproductive processes. Important Findings The transgenerational effects depended on both maternal and offspring seed morphs. Drought stress induced the maternal plants originated from ray seeds to increase the relative proportion of ray- vs. disc-seed offspring and transmit stronger adaptive transgenerational effects to the former, whereas its effects on the maternal plants originated from disc seeds were exactly opposite. These different effects on offspring corresponded with different seed abscisic acid and soluble sugar contents but not seed provisioning. Dimorphism-dependent transgenerational effects allow large divergence of drought tolerance among offspring, which may be an important but under-explored mechanism to balance the needs of population maintenance and range expansion in seed-dimorphic species.

中文翻译：

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依赖二态性的跨代效应促进了 Synedrella nodiflora (L.) Gaertn 耐旱性的分化

摘要 目的 植物中的跨代效应会对可预测和不可预测环境的适应产生相反的影响。虽然种子二态植物可以产生具有不同适应策略的二态后代，但尚不清楚跨代效应和种子二态性是否可能相互作用以决定后代的适应。本研究旨在探讨种子二态母本植物是否以及如何对二态后代产生不同的跨代效应。方法 Synedrella nodiflora 被选为研究物种，它适应广泛的土壤水分梯度并产生两种不同类型的种子（轻型圆盘种子与重型射线种子）。在温室里，S. nodiflora 在干旱胁迫下种植了两代，以测试跨代对后代表现和死亡率的影响是否取决于母体或后代的种子形态。通过测量母本植物的种子供应和化学调节剂以及相关的生殖过程，探索了潜在的调节机制。重要发现 跨代效应取决于母体和后代的种子形态。干旱胁迫诱导射线种子来源的母本植物增加射线种子与圆盘种子后代的相对比例，并将更强的适应性跨代效应传递给前者，而其对源自圆盘种子的母本植物的影响恰恰相反。这些对后代的不同影响对应于不同的种子脱落酸和可溶性糖含量，而不是种子供应。依赖二态性的跨代效应允许后代之间的耐旱性有很大差异，这可能是平衡种子二态性物种的种群维持和范围扩大需求的重要但未充分探索的机制。