Chinese Journal of Oceanology and Limnology

, Volume 32, Issue 2, pp 365–371

Zoospore-derived monoecious gametophytes in Undaria pinnatifida (Phaeophyceae)

  • Jing Li (李静)
  • Shaojun Pang (逄少军)
  • Tifeng Shan (单体锋)
  • Feng Liu (刘峰)
  • Suqin Gao (高素芹)
Biology

DOI: 10.1007/s00343-014-3139-x

Cite this article as:
Li, J., Pang, S., Shan, T. et al. Chin. J. Ocean. Limnol. (2014) 32: 365. doi:10.1007/s00343-014-3139-x

Abstract

The annual life cycle of the brown seaweed Undaria pinnatifida (Harvey) Suringer comprises a macroscopic diploid sporophyte stage and a microscopic haploid gametophyte stage. In 2011, an unusual zoospore-derived monoecious gametophyte isolate (designated as line 10-5-3) of U. pinnatifida was observed. To understand this phenomenon, a comprehensive screening of eighty-two previously identified male gametophyte cultures, isolated from three randomly selected cultivars (lines 10, 7, and 5) was performed. Thirty-six of the isolates developed both antheridia and oogonia on the same filamentous fragment in a standard gametogenesis test (SGT: 18°C, 60 μmol photons/(m2·s)). Selfing of the monoecious gametophyte or crossing it with a normal male gametophyte both gave rise to morphologically normal sporophytic offspring. However, crossing resulted in a much higher fertilization rate (89.7%). The hybrid and selfed sporophytic offspring were grown to maturity in flow tanks at an ambient temperature of 10–18°C over a period of 69 days. Active zoospores were released from both types of mature sporophylls. The majority of these developed into male gametophytes, while 15%–20% developed into the observed monoecious structures on the same filament. Using PCR amplification it was found that all the monoecious gametophyte isolates and the sporophytic offspring resulting from the selfing and crossing lacked the femalelinked microsatellite sequence (a part of the locus Up-AC-2A8, GenBank accession No. AY738602.1), indicating their male nature. U. pinnatifida is an invasive species in some regions and the implications of the above findings for this species in nature are briefly discussed.

Keyword

antheridia kelp monoecious gametophyte oogonia Undaria pinnatifida 

Copyright information

© Chinese Society for Oceanology and Limnology, Science Press and Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Jing Li (李静)
    • 1
    • 2
  • Shaojun Pang (逄少军)
    • 1
  • Tifeng Shan (单体锋)
    • 1
  • Feng Liu (刘峰)
    • 1
  • Suqin Gao (高素芹)
    • 1
  1. 1.Institute of OceanologyChinese Academy of SciencesQingdaoChina
  2. 2.University of Chinese Academy of SciencesBeijingChina