Institute of Environment and Ecology & School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China.
State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, China.
Ecotoxicology. 2020 Sep;29(7):1095-1104. doi: 10.1007/s10646-020-02251-y. Epub 2020 Jul 14.
Several invasive alien plants (IAP) can trigger evidently allelopathy on the seed germination and seedling growth (SgSg) of native plant species (NPS). The getting worse condition with heavy metal pollution (e.g., cadmium) can significantly impact SgSg of plant species. Silicon can offset the adverse effects of environmental pressure on the growth and development of plant species. Thus, it is important to evaluate the influences of silicon on the allelopathy of IAP on SgSg of NPS under cadmium stress to better understand the mechanism driving the successful colonization of IAP. This study focuses on the allelopathy of the infamous IAP Solidago canadensis L. (Canada goldenrod; by using leaf extracts) on SgSg of NPS Lactuca sativa L. under the separated and mixed silicon and cadmium addition. S. canadensis triggers notably allelopathy on SgSg of L. sativa and gradually upsurges with increasing leaf extract concentration. Thus, the growth performance of NPS will be gradually reduced with an increasing degree of S. canadensis invasion. Cadmium evidently declines SgSg of L. sativa due to the broken balance of plant species for nutrient absorption. The mixed S. canadensis leaf extracts and cadmium synergistically impact seed germination of L. sativa but antagonistically affect seedling growth of L. sativa. The mixed silicon and cadmium intensify the allelopathy of S. canadensis on SgSg of L. sativa probably due to the increased effective content of cadmium in plant roots under silicon addition. Thus, the mixed silicon and cadmium will be advantageous to the following invasion process of IAP largely via the depressed SgSg of NPS.
几种入侵的外来植物（IAP）会对本地植物物种（NPS）的种子萌发和幼苗生长（SgSg）产生明显的化感作用。重金属污染（如镉）的恶化状况会显著影响植物物种的 SgSg。硅可以抵消环境压力对植物物种生长发育的不利影响。因此，评估硅对 IAP 在镉胁迫下对 NPS 的化感作用的影响，对于更好地理解 IAP 成功定植的驱动机制非常重要。本研究集中于臭名昭著的 IAP 加拿大一枝黄花（Solidago canadensis L.；通过叶片提取物）对 NPS 莴苣（Lactuca sativa L.）的 SgSg 的化感作用，在单独和混合硅和镉添加的情况下。加拿大一枝黄花对莴苣的 SgSg 产生明显的化感作用，并且随着叶片提取物浓度的增加逐渐增加。因此，随着加拿大一枝黄花入侵程度的增加，NPS 的生长性能将逐渐降低。由于植物物种对养分吸收的平衡被打破，镉显著降低了莴苣的 SgSg。混合的加拿大一枝黄花叶片提取物和镉协同作用影响莴苣的种子萌发，但拮抗作用影响莴苣的幼苗生长。混合硅和镉增强了加拿大一枝黄花对莴苣 SgSg 的化感作用，可能是由于硅添加后植物根系中镉的有效含量增加。因此，混合硅和镉将有利于 IAP 的后续入侵过程，主要是通过抑制 NPS 的 SgSg。
