Am Nat. 2019 Oct;194(4):482-487. doi: 10.1086/704773. Epub 2019 Aug 14.
Relatives often interact differently with each other than with nonrelatives, and whether kin cooperate or compete has important consequences for the evolution of mating systems, seed size, dispersal, and competition. Previous research found that the larger of the size dimorphic seeds produced by the annual plant suppressed germination of their smaller sibs by 25%-60%. Here, we found evidence for kin recognition and sibling rivalry later in life among seedlings that places seed-seed interactions in a broader context. In experiments with size dimorphic seeds, seedlings reduced the growth of sibling seedlings by ∼40% but that of nonsibling seedlings by ∼25%. These sequential antagonistic interactions between seeds and then seedlings provide insight into conflict and cooperation among kin. Kin-based conflict among seeds may maintain dormancy for some seeds until the coast is clear of more competitive siblings. If so, biotically induced seed dormancy may be a unique form of cooperation, which increases the inclusive fitness of maternal plants and offspring by minimizing competition among kin.
亲属之间的相互作用通常不同于非亲属之间的相互作用，亲属之间的合作或竞争对交配系统、种子大小、散布和竞争的进化有重要影响。先前的研究发现，一年生植物产生的大小二型种子中较大的种子会抑制其较小的同胞种子发芽 25%-60%。在这里，我们在幼苗后期发现了亲缘识别和同胞竞争的证据，将种子-种子相互作用置于更广泛的背景下。在大小二型种子的实验中，幼苗将同胞幼苗的生长减少了约 40%，而将非同胞幼苗的生长减少了约 25%。种子和随后的幼苗之间的这种连续的拮抗相互作用提供了关于亲属之间冲突和合作的深入了解。种子之间基于亲缘关系的冲突可能会使一些种子保持休眠状态，直到更有竞争力的同胞远离为止。如果是这样，生物诱导的种子休眠可能是一种独特的合作形式，通过最小化亲属之间的竞争，增加了母株和后代的适合度。
