Base water potential for germination of radiata pine and buddleia seeds adjusts in response to time, seed-bed water potential and supra-optimal temperatures

Authors

  • M. Bloomberg
  • M.S. Watt

DOI:

https://doi.org/10.33584/rps.14.2008.3177

Abstract

Hydrothermal germination models are mathematical models which predict germination time of seeds for a specified seed-bed temperature (T) and water potential (Ψ). In this paper, the commonly observed decline in seed germination at supra-optimal temperatures is investigated by fitting a hydrothermal time model to germination data from two unrelated plant species (Buddleia davidii and Pinus radiata). For both these species, reduced germination rates and germination percentages above optimum temperatures (20°C and 25°C for P. radiata and B. davidii, respectively) were successfully modelled by an upward shift in the seeds' base water potential (Ψb) during germination. The upwards shift in Ψb was shown to be an asymptotic function of time to germination, but with the rate increased by higher temperatures and moister seed-bed conditions. The physiological and ecological implications of this proposed model of the observed decline in germination at supraoptimal temperatures are discussed. Keywords: hydrothermal, model, Pinus radiata, Buddleia davidii

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Published

2010-01-01

How to Cite

Bloomberg, M., & Watt, M. (2010). Base water potential for germination of radiata pine and buddleia seeds adjusts in response to time, seed-bed water potential and supra-optimal temperatures. NZGA: Research and Practice Series, 14, 113–118. https://doi.org/10.33584/rps.14.2008.3177

Issue

Vol. 14 (2008): Seed Symposium: Seeds for Futures

Section

Past volumes

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