ARC Centre for Mine Site Restoration, School of Molecular and Life Science, Curtin University, Bentley, Western Australia, Australia.
Department of Biodiversity, Kings Park Science, Conservation and Attractions, Kings Park, Western Australia, Australia.
PLoS One. 2021 Jun 9;16(6):e0242035. doi: 10.1371/journal.pone.0242035. eCollection 2021.
To achieve global ambitions in large scale ecological restoration, there is a need for approaches that improve the efficiency of seed-based interventions, particularly in overcoming the bottleneck in the transition from germination to seedling establishment. In this study, we tested a novel seed-based application of the plant stress modulator compound salicylic acid as a means to reduce seedling losses in the seed-to-seedling phase. Seed coating technology (encrusting) was developed as a precursor for optimising field sowing for three grass species commonly used in restoration programs, Austrostipa scabra, Microlaena stipoides, and Rytidosperma geniculatum. Salicylic acid (SA, 0.1mM) was delivered to seeds via imbibition and seed encrusting. The effects of SA on seed germination were examined under controlled water-limited conditions (drought resilience) in laboratory setting and on seed germination, seedling emergence, seedling growth and plant survival in field conditions. Salicylic acid did not impact germination under water stress in controlled laboratory conditions and did not affect seedling emergence in the field. However, seedling survival and growth were improved in plants grown from SA treated seeds (imbibed and encrusted) under field conditions. When SA delivery methods of imbibing and coating were compared, there was no significant difference in survival and growth, showing that seed coating has potential to deliver SA. Effect of intraspecific competition as a result of seedling density was also considered. Seedling survival over the dry summer season was more than double at low seedling density (40 plants/m2) compared to high seedling density (380 plants/m2). Overall, adjustment of seeding rate according to expected emergence combined with the use of salicylic acid via coating could improve seed use efficiency in seed-based restoration.
为了实现大规模生态恢复的全球目标，需要采用提高基于种子的干预措施效率的方法，特别是克服从萌发到幼苗建立的过渡瓶颈。在这项研究中，我们测试了植物应激调节剂水杨酸作为一种减少种子到幼苗阶段幼苗损失的新型基于种子的应用。种子包衣技术（包被）被开发为优化三种常用于恢复计划的草种（Austrostipa scabra、Microlaena stipoides 和 Rytidosperma geniculatum）田间播种的前身。水杨酸（SA，0.1mM）通过吸胀和种子包被传递到种子中。在实验室控制水分限制条件下（耐旱性）检查了 SA 对种子萌发的影响，并在田间条件下检查了种子萌发、幼苗出苗、幼苗生长和植物存活的影响。SA 在受控实验室条件下的水分胁迫下不影响萌发，也不影响田间的幼苗出苗。然而，从 SA 处理的种子（吸胀和包被）中生长的植物的幼苗存活率和生长得到了改善。当比较吸胀和包衣的 SA 传递方法时，在存活率和生长方面没有显着差异，表明种子包衣具有传递 SA 的潜力。还考虑了由于幼苗密度导致的种内竞争的影响。与高幼苗密度（380 株/平方米）相比，在低幼苗密度（40 株/平方米）下，幼苗在旱季的存活率提高了一倍以上。总体而言，根据预期出苗调整播种率并结合使用包衣的水杨酸可以提高基于种子的恢复中的种子使用效率。
