ISSN:
1573-5117
Keywords:
agar
;
carrageenan
;
molecular systematics
;
phycocolloids
;
rbcL
;
Rhodophyta
;
seaweeds
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract A hypothesis of phylogenetic relationships inferred by parsimony analysis of plastid-encoded rbcL sequences is presented for red algae containing agar- and carrageenan-like phycocolloids; rbcL encodes the large subunit of ribulose 1,5 bisphosphate carboxylase/oxygenase. Previous studies have shown that Floridean families that contain sulfated galactans as cell wall components are resolved as a monophyletic clade sister to the agarophyte order Ahnfeltiales. Families that have been identified as containing kappa-type carrageenans, often in addition to lambda-type carrageenans, are resolved in three clades: (1) a complex containing the families Solieriaceae, Cystocloniaceae, Hypneaceae, Caulacanthaceae, Tichocarpaceae, Furcellariaceae, and the genera Turnerella and Opuntiella; (2) the Gigartinaceae and Phyllophoraceae, and (3) the genus Endocladia. Except for Tichocarpus and Endocladia, these are all members of the Gigartinales sensu Kylin (1956). Most of the families previously placed in the Cryptonemiales by Kylin appear to contain only lambda-type carrageenans. These fall into two groups, one that clusters with typical carrageenophyte- and the other with typical agarophyte-taxa. The first of these includes the families Polyideaceae, Kallymeniaceae, Dumontiaceae, and Rhizophyllidaceae. The second includes the type family of the Cryptonemiales, the Halymeniaceae, which is divisible into two well-supported clades, one of which possesses special lambda-like carrageenans, the aeodans, and the Schizymeniaceae, a recently created family containing two former gigartinalean genera. The agarophyte orders Gelidiales, Gracilariales and Ceramiales are well resolved as monophyletic clades, but their topological positions are poorly resolved. The Gelidiales and Ceramiales are associated, but the Gracilariales is included in a clade that contains families belonging to the Rhodymeniales, a possible agarophyte order. Finally, two groups that may contain lambda-like carrageenans, the Plocamiales and the Sarcodiaceae, are resolved as separate clades.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00047797
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