Agüero-Martínez Paola Fernanda, Cardozo Leonardo, Gómez Carlos A, López-Spahr Diego, Baskin Carol C, Bertero Daniel, Galíndez Guadalupe, Curti Ramiro
Facultad de Ciencias Naturales, Universidad Nacional de Salta (UNSa), Av. Bolivia 5150, Salta 4400, Argentina.
Laboratorio de Microscopía Electrónica de Barrido (LASEM), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Salta (UNSa), Av. Bolivia 5150, Salta 4400, Argentina.
Plants (Basel). 2024 Oct 9;13(19):2832. doi: 10.3390/plants13192832.
, the putative wild ancestor of quinoa, is a source of traits that could improve the tolerance of crop quinoa to high temperatures. However, seeds of have physiological dormancy (PD), which is an obstacle for plant propagation and use in breeding programs. We studied the intraspecific variability in morpho-anatomical traits of embryo covering structures and their association with PD. We also evaluated the effects of different dormancy-breaking treatments on PD alleviation and germination. Seeds were dispersed with a remnant perianth and a persistent pericarp that could be removed by scraping. The seed coat was formed by palisade cells impregnated with tannins, and the seed contained a thin layer of peripheral endosperm surrounding the embryo. In our investigation, the thickness of the pericarp (P) and/or seed coat (SC) varied among populations. Populations with higher P and/or SC thickness showed lower percentages of germination and water absorption. The combined dormancy-breaking treatment (bleach + perforated coverings + gibberellic acid) promoted dormancy release and increased germination. seeds showed non-deep physiological dormancy. Based on previous knowledge about quinoa, and our results, we conclude that embryo coverings, especially the seed coat, have an important role in dormancy control, imposing a mechanical restraint on radicle emergence.
藜麦的假定野生祖先，是一种可改善藜麦作物耐高温耐受性的性状来源。然而，其种子具有生理休眠（PD），这对植物繁殖及在育种计划中的应用构成了障碍。我们研究了胚胎覆盖结构形态解剖特征的种内变异性及其与生理休眠的关联。我们还评估了不同破眠处理对缓解生理休眠及种子萌发的影响。种子带有残留花被和可通过刮擦去除的宿存果皮进行传播。种皮由充满单宁的栅栏细胞构成，种子包含围绕胚胎的一层薄薄的外周胚乳。在我们的研究中，果皮（P）和/或种皮（SC）的厚度在不同种群间存在差异。果皮和/或种皮厚度较高的种群发芽率和吸水率较低。联合破眠处理（漂白剂 + 穿孔覆盖物 + 赤霉素）促进了休眠解除并提高了发芽率。其种子表现出非深度生理休眠。基于先前关于藜麦的知识以及我们的研究结果，我们得出结论，胚胎覆盖物，尤其是种皮，在休眠控制中起重要作用，对胚根突出形成机械限制。
