Abstract Survival during burial is dependent upon a seed's ability to resist pathogen pressure and physiological aging. Several studies support a positive interspecific relationship between seed survival in soil and seed coat thickness. Our research attempted to understand if a similar intraspecific relationship occurs in Rudbeckia mollis (Asteraceae) seeds of different mass. Seeds were collected in August 2016 and separated into light (383 ± 7 µg), intermediate (409 ± 8 µg), and heavy (447 ± 10 µg) mass classes. Pericarp thickness was measured on fresh sections of seeds from each class. Seeds were buried 25 cm deep in a non-irrigated wildflower plot and monitored for viability with a standard germination test over 24 months. Final germination percentage varied from 0-98% with an overall mean of 82 ± 30% among all mass classes. Germination percentage and germination rate correlated positively with soil temperature suggesting dormancy cycling that is consistent with non-deep physiological dormancy. There was no consistent relationship between the likelihood of germination and seed mass but heavy class seeds were more likely to be recovered intact following burial. Pericarp thickness ranged from 24.7-41.4 µm and there was a weak positive relationship with mass. This research suggests no short-term relationship between intra-population seed mass and viability loss during burial. However, thicker seed coats in higher mass seeds may confer greater resistance to pathogen pressure. This research is supportive of a positive intra-population relationship between survival in soil and seed coat thickness.

中文翻译：

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大量埋藏期间的种群内种子存活

摘要 埋藏期间的存活取决于种子抵抗病原体压力和生理老化的能力。几项研究支持种子在土壤中的存活率与种皮厚度之间存在正的种间关系。我们的研究试图了解在不同质量的 Rudbeckia mollis（菊科）种子中是否存在类似的种内关系。种子于 2016 年 8 月收集并分为轻 (383 ± 7 µg)、中 (409 ± 8 µg) 和重 (447 ± 10 µg) 质量等级。在来自每个类别的种子的新鲜切片上测量果皮厚度。将种子埋在未灌溉的野花地中 25 厘米深，并在 24 个月内通过标准发芽测试监测其活力。最终发芽百分比从 0-98% 不等，所有质量等级的总体平均值为 82 ± 30%。发芽率和发芽率与土壤温度呈正相关，表明休眠循环与非深层生理休眠一致。发芽的可能性和种子质量之间没有一致的关系，但重类种子在埋葬后更有可能完好无损地恢复。果皮厚度范围为 24.7-41.4 µm，与质量呈弱正相关。这项研究表明，在埋藏期间，种群内种子质量与生存力损失之间没有短期关系。然而，较大质量种子中较厚的种皮可能会赋予对病原体压力的更大抵抗力。这项研究支持在土壤中的存活率和种皮厚度之间存在正的种群内关系。