Department of Geobotany and Plant Ecology, University of Lodz, 12/16 Banacha St., 90-237, Lodz, Poland.
Sci Rep. 2017 May 16;7(1):1959. doi: 10.1038/s41598-017-02035-1.
There is large variation in seed mass within P. oreoselinum (L.) Moench selected for the present study from two contrasting habitats: roadside and oak forest. Effect of seed position within a plant and of soil nutrients on seed mass, germination and seedlings growth were studied. Within an individual plant, seed mass decreased with umbel order and seeds from the central umbellet of the umbel were lighter than those from the outer edge, suggesting that variation in seed mass within an individual plant was due to the position effect. There was a significant relationship between seed mass and total germination. Covariate analysis showed the differences between sites in seed macronutrient contents were caused by respective differences in seed mass and soil macronutrients. This indicates substantial variation in the amount of reserves initially available for seedling growth. In conclusion, phenotypically-based variation in seed mass may arise from soil conditions, maternal traits or combination of the two. High variability in seed mass of P. oreoselinum favours its widespread geographic distribution. These results suggest that with respect to germination characteristics large seeds from primary order have a competitive advantage over small seeds produced on secondary umbels because they have higher overall germination.
本研究从两种截然不同的生境（路边和橡树林）中选择了 P. oreoselinum（L.）Moench 的种子进行研究，发现其种子质量存在很大差异。研究了种子在植物内的位置和土壤养分对种子质量、发芽和幼苗生长的影响。在个体植物内，种子质量随伞序顺序而降低，并且来自伞序中央小伞形花序的种子比来自外部边缘的种子轻，这表明个体植物内的种子质量变化是由于位置效应引起的。种子质量与总发芽率之间存在显著关系。协变量分析表明，种子宏量营养素含量在地点之间的差异是由种子质量和土壤宏量营养素的各自差异引起的。这表明初始可用于幼苗生长的储备量存在很大差异。总之，基于表型的种子质量变化可能源于土壤条件、母体性状或两者的组合。P. oreoselinum 种子质量的高度可变性有利于其广泛的地理分布。这些结果表明，就发芽特征而言，来自一级序的大种子比来自二级序的小种子具有竞争优势，因为它们具有更高的整体发芽率。
