Developmental morphology and phylogeny of Paraglossum amsleri sp. nov. (Delesseriaceae, Rhodophyta), a species from Antarctica previously known as Delesseria lancifolia

Abstract:

Paraglossum amsleri S.-M. Lin & Hommersand sp. nov. (Delesseriaceae, Rhodophyta), a species previously reported as Delesseria lancifolia from the Antarctic Peninsula and associated Antarctic Islands, was investigated based on rbcL sequence analysis and morphological evidence. The genetic distance between the type species, Paraglossum lancifolium and ‘D. lancifolia’ from Antarctica was 3.8% (52 pairwise differences); whereas, the interspecific genetic divergence within the genus Paraglossum ranged from 0.95% to 6.96% (13–95 pairwise base differences). Procarps and cystocarps were formed in bladelets with broad bases borne along the margins of the midrib and macroscopic veins or scattered over the thallus surface in P. lancifolium; whereas, they were formed in bladelets with short stalks borne along the midrib and macroscopic veins in P. amsleri. Tetrasporangia were formed in bladelets initiated from surface cells in P. lancifolium but were produced in cells in linear files alongside the margins and from the surfaces of the midrib and macroscopic veins in P. amsleri. Intercalary cell divisions were absent in primary cell rows that formed the midrib in all species of Paraglossum but occurred frequently in second and higher orders of cell rows. Fourth-order cell rows were produced both abaxially and adaxially in P. lancifolium but were formed only adaxially in rapidly growing tips of P. amsleri. Paraglossum salicifolium, the only other species of this genus known from Antarctica, exhibited a pattern of vegetative growth similar to that seen in P. amsleri. The formation of uniseriate filaments from the pericarps of P. salicifolium was a character that that clearly distinguished this species from P. amsleri, in which the pericarps were smooth. New species combinations were proposed as Paraglossum for Delesseria crozetii Levring, Delesseria macloviana Skottsberg in Kylin & Skottsberg and Delesseria minor Baardseth.

Key Words::

• Antarctica
• Delesseria
• Delesseriaceae
• Developmental morphology
• Paraglossum
• Paraglossum amsleri sp. nov.
• Phylogeny
• rbcL
• Red algae
• Rhodophyta

ACKNOWLEDGEMENTS

This project was supported mainly by a research grant from Ministry of Technology and Science (Taiwan) (MOST 102-2628-B-019-002-MY3) to S.-M. Lin. Hommersand was supported by NSF grant DEB0937978 to J.M. Lopez Bautista, M.H. Hommersand and S. Fredericq. We thank Charles and Margaret Amsler for providing material from the Antarctic Peninsula and Y.-S. Chiou and Yi-Chi Wang for helping with DNA sequencing and specimen processing. We thank M.J. Wynne and C. Schneider for their informative and helpful reviews of this paper.

SUPPLEMENTARY DATA

Supplementary data associated with this article can be found online at http://dx.doi.org/10.2216/15-85.1.s1.