Culture techniques for and reproduction in Porphyra umbilicalis kuetzing (P.UM.1, JGI sequencing project): Insights from amplified fragment length polymorphisms (aflps)

• Published in: Phycologia (Oxford) Vol. 48; no. 4
• Main Authors: Blouin, NA, Brawley, SH
• Format: Journal Article
• Language: English
• Published: 01.07.2009
• Subjects: Porphyra umbilicalis; ANW, USA, Maine; ANE, Europe
• ISSN: 0031-8884

Porphyra umbilicalis haplotype "P.um.1" was isolated from a collection made on the Maine (USA) shore. This isolate is the subject of a complete genome-sequencing project by the US Department of Energy. Culture techniques for P.um.1 and characterization of its parent population in Maine will aid future investigations by scientists with P.um.1. Haplotype P.um.1 has been subcultured for 3 generations as part of our contribution to the ongoing genome project. The generation time from neutral spore germination to reproductive maturity is < 5 months. Porphyra umbilicalis is described as being mostly sexual in Europe; however, collections made each month over multiple years (n > 4000) in P.um.1's parent population, show that P. umbilicalis reproduces exclusively via neutral spores on the Maine coast. This suggests that the population could be clonal and lack genetic diversity. To investigate genetic diversity, we used amplified fragment length polymorphisms (AFLPs) with individuals of P. umbilicalis from locations where asexual or sexual reproduction is known to occur. If individuals were clones of each other, then their AFLP profiles would be expected to be identical. One hundred P. umbilicalis individuals were collected from four locations, n=25 per site. The sites selected included three locations in the USA (two from Maine) and a fourth location in the UK (sexual individuals). Genetic analysis shows that individuals within sites are more closely related than individuals between sites. Amplified fragment length polymorphisms' analysis revealed genetic diversity within all sites; thus, we conclude that USA populations are not a single clone.