Life cycle of Punctaria latifolia (Chordariaceae, Phaeophyceae) from the coast of Buenos Aires Province, South America

GAUNA, M.C.; PARODI, E.R

ALGOLOGICAL STUDIES

E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart

Lugar: Stuttgart, Germany; Año: 2010 vol. 134 p. 55 - 66

0342-1120

The objective of this study was to describe the morphology of Punctaria latifoliaindividuals from the natural environment, their life cycle under culture conditions andthe caryology of different phases. The life cycle of Punctaria latifolia was studied underculture conditions (140 μmol m-2 s-1; 12 h/12 h; 21 ± 1 °C). Fertile sporophytes were collectedin the intertidal zone of Bahía San Blas (Buenos Aires, Argentina, South America),in August and December 2003. These macroscopic laminar plants were found adhered tothe rocky substrate and on Spartina alterniflora plants. Sporophytes from the natural environmentpresented both plurilocular and unilocular sporangia, which released plurisporesand unispores, respectively. The asexual reproduction was evidenced by the germination ofunispores by formation of a single - pole germination that formed microscopic filamentousgametophytes. Terminal and intercalar gametangia released isogametes. Zygotes reconstitutedthe macroscopic phase. Chromosome counts gave 16 and 8 for sporophytic- and gametophytic-phases, respectively. This species presented a haplodiplobiontic heteromorphiclife cycle as well as a direct type, when plurispores produced plethysmothalli.