Chin J Plant Ecol ›› 2010, Vol. 34 ›› Issue (4): 418-426.DOI: 10.3773/j.issn.1005-264x.2010.04.007

• Research Articles • Previous Articles     Next Articles

Effects of inflorescence position on seed production and seedling establishment in Ligularia virgaurea

XIE Tian-Peng*(), DU Gou-Zhen**(), ZHANG Ge-Fei, ZHAO Zhi-Gang   

  1. Key Laboratory of Arid and Grassland Ecology of Ministry of Education, Lanzhou University, Lanzhou 730000, China
  • Received:2009-05-18 Accepted:2009-10-30 Online:2010-05-18 Published:2010-04-01
  • Contact: DU Gou-Zhen


Aims Position-effect of seeds within inflorescences of flowering plants is a common phenomenon, but its influence on seedling establishment is not well known. Our objective was to determine: 1) the pattern of seed production within inflorescences in Ligularia virgaurea (top, middle and bottom of inflorescences) and 2) if position-effect exists, whether it affects seed germination and seedling establishment.

Methods We surveyed seed production of L. virgaurea in the field, seed germination under an alternating temperature regime (15 °C / 5 °C; 12 h light/dark) in the laboratory and seedling establishment under 25% shade by potted plants in the field. One-way ANOVA was used to determine the effects of seed position on seed set, seed weight, ovule number, seed number, germination percentage, initial germination time, emergence percentage, survival percentage, root-shoot ratio (R/S), total biomass (TB) and net photosynthetic rate (Pn). Tukey’s test was used to determine the difference between average values.

Important findings Seed production of L. virgaurea is affected significantly by position within an inflorescence: seed set and seed mean weight are greatest at the top, mean number of ovules is highest at the bottom, and the middle position has the most seeds. Initial germination time is earlier for seeds from the bottom than top, germination percentage and emergence percentage are not significantly different among different positions, and survival percentage among three positions is nearly consistent. R/S and Pn are top > bottom, but TB is not significantly different. Seedling traits are consistent under two different rates of fertilizer application. Results imply that the seeds from different positions have inherently different germination and seedling growth strategies. Top seeds can disperse further and have stronger seedling establishment ability than bottom seeds. Therefore, top seeds have greater ecological significance for sexual recruitment, regeneration and colonizing new habitats.

Key words: germination, Ligularia virgaurea, positional effect, seed production, seedling traits