Bibliographic Detail
Lin, S.-M., Fredericq, S. & Hommersand, M.H., 2012
Reference:
Lin, S.-M., Fredericq, S. & Hommersand, M.H. (2012). Molecular phylogeny and developmental studies of Apoglossum and Paraglossum (Delesseriaceae, Rhodophyta) with a description of Apoglosseae trib. nov. European Journal of Phycology 47(4): 366-383.
Abstract:
Our morphological and molecular studies indicate that species from the Southern Hemisphere
previously placed in Delesseria belong in Paraglossum and that Paraglossum and Apoglossum
comprise a separate tribe, the Apoglosseae, S.-W. Lin, Fredericq & Hommersand, trib. nov., family
Delesseriaceae. From a vegetative perspective the Apoglosseae is readily recognized because some
or all fourth-order cell rows are formed on the inner sides of third order cell rows. All fourth order
cell rows grow adaxially in Apoglossum, whereas both adaxial and abaxial cell rows are present in
Paraglossum. Periaxial cells do not divide in Apoglossum, whereas they divide transversely in
Paraglossum in the same way as in Delesseria. Major branches are formed mainly from the margins
of midribs in the Apoglosseae. The procarp consists of a straight carpogonial branch and two sterile
cells with the second formed on the same side as the first. The carpogonium cuts off two connecting
cells in tandem from its apical end with the terminal cell nonfunctional and the subterminal cell
typically fusing with the auxiliary cell. Gonimoblast filaments radiate in all directions from the
gonimoblast initials and produce carposporangia terminally in branched chains, with pit connections
between the inner gonimoblast cells broadening and enlarging. The auxiliary cell, supporting cell and
sterile cells unite into a fusion cell, which remains small in Apoglossum but incorporates the
branched inner gonimoblast filaments and cells in the floor of the cystocarp in Paraglossum.
Elongated inner cortical cells seen in mature cystocarps in the Delesserieae are absent in the
Apoglosseae. Phylogenetic studies based on rbcL (RuBisCo Large subunit) sequence analyses
strongly support the recognition of the Apoglosseae within the subfamily Delesserioideae, family
Delesseriaceae, in agreement with our previous observations based primarily on analyses of large
subunit ribosomal DNA (LSU).
