全 文 ：植 物 分 类 学 报 45 (5): 719–726(2007) doi:10.1360/aps06074
Acta Phytotaxonomica Sinica http://www.plantsystematics.com
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Received: 27 April 2006 Accepted: 23 May 2007
Supported by the National Natural Science Foundation of China, Grant Nos. 30470118, 30270119.
* Author for correspondence. E-mail: xiesl@sxu.edu.cn; Tel.: 86-351-7018121.
Tuomeya Harvey, a genus of freshwater Rhodophyta newly
recorded from China
FENG Jia XIE Shu-Lian* YAO Ge
(School of Life Science and Technology, Shanxi University, Taiyuan, Shanxi 030006, China)
Abstract Tuomeya Harvey (Tuomeya americana (Kützing) Papenfuss) is reported as new
record to China. The specimens were collected from Xuzhou in Jiangsu, East China. This
genus is characterized by a cartilaginous thallus and solid cortex, which is composed of
numerous compact cortical cells. Its carpogonial branches are twisted. In addition to
describing the morphological and reproductive structures of T. americana in detail, we also
use rbcL gene sequences aligned with the previously published sequences of T. americana
from North America. Tuomeya includes only one species, which was previously known from
North America and South Africa.
Key words Tuomeya, Batrachospermaceae, Batrachospermales, freshwater Rhodophyta,
rbcL gene, new record, China.
While collecting plants of freshwater Rhodophyta from Xuzhou (34°1202.82" N,
117°1546.11" E) in Jiangsu, a small cartilaginous plant belonging to the Batrachospermales
was obtained that was different from other reported genera and species in China. The
specimen was identified as Tuomeya americana (Kützing) Papenfuss and represents a new
record for China. We described its morphological characters. In addition, its chloroplast
ribulose-1, 5-bisphosphate carboxylase/oxygenase (rbcL) gene was sequenced and aligned
with the previously published sequences of T. americana from North America (Vis et al.,
1998; Kapraun et al., 2007).
1 Material and methods
The materials were collected on rocks and stones in flowing water from Bajian Spring,
Xuzhou, Jiangsu, on 24 March, 2006. Specimens used for the morphological study were
preserved in freshwater containing 4%–10% formalin, and those used for molecular study
were frozen at –20 ℃. The vegetative and reproductive structures were examined with a light
microscope (Olympus BX51) and with a dissecting microscope (Olympus SZ30).
Photographs were taken with a camera (Olympus C5060) attached to the microscope.
Specimens used in this study were deposited in the Herbarium of Shanxi University (SXU).
For DNA analysis, the frozen samples were ground in liquid nitrogen, and DNA was
extracted following the protocol described by Saunders (1993), except that samples were
purified using the Wizard DNA Clean-up System (Promega, Madison, Wisconsin, USA.)
according to the manufacturer’s protocol. Polymerase chain reaction (PCR) amplification was
performed in 580BR thermocycler (2686, BIO-RAD, USA). The following cycle was used for
amplification: initial denaturation at 95 ℃ for 5 min, 35 cycles at 94 for 1℃ min, 60 for ℃
1min and 72 for 2 min, and a final extension at 72 ℃ ℃ for 2 min. The primer pair F160
(5CCT CAA CCA GGA GTA GAT CC3) and rbcL reverse (5ACA TTT GCT GTT GGA
GTC TC3) was used to amplify a 1282 bp fragment of rbcL gene. PCR products were
Acta Phytotaxonomica Sinica Vol. 45 720
prepared for sequencing with the Gel Extraction Mini Kit (Huashun, Watson Biotechnologies,
Inc., Shanghai, China) according to the manufacturer’s protocol. The PCR products were
sequenced using the BigDye® Terminator v3.1 Cycle Sequencing Kit [Applied Biosystems
(ABI), Foster City, CA, USA], ABI PrismTM 3730XL DNA Analyzer and ABI PrismTM
377XL DNA Sequencer. Sequencing reactions were prepared and sequenced with the
amplification primers in two directions.
The sequences were compared with other T. america from USA, which had been
deposited in GenBank (Vis et al., 1998; Kapraun et al., 2007). The sequences were aligned
using CLUSTAL X software, and final adjustments were made by eye. The MEGA (version
3.0) program was used to calculate sequence statistics (Kumar et al., 2004).
2 Results
2.1 Morphological descriptions
Tuomeya Harvey in Smithsonian Contributions to Knowledge 10 (2): 64. 1858.——
Batrachospermum section Tuomeya (Harvey) Necchi & Entwisle in Phycologia 29: 478.
1990.
托氏藻属
Thalli are irregularly branched, cartilaginous, and solid. Plants are composed of
longitudinal axial cell filament with numerous whorls of lateral branches and cortical
filaments. Spermatangia are ovoid, terminating on lateral branch. Carpogonium-bearing
branches are short, arising from periaxial cells or cells of fascicles. Carpogonia are
asymmetrical with elongate-conical or club-shaped trichogynes. Carposporophytes are
definite in shape. Gonimoblast filaments are the radially branched type, arising from the dense
mass of fusion cells (gonimoblast placenta), including the original involucral cells.
Type: Tuomeya americana (Kützing) Papenfuss.
Tuomeya americana (Kützing) Papenfuss in Taxon 7: 104. 1958; Kaczmarczyk et al. in
Journ. Phycology 28: 850, figs. 2–10, 1992; Kumano in Freshwater Red Algae of the World
238. 2002. ——Baileya americana Kützing in Tab. Phycol. VII: 35, pl. 87, III, f, f′, g. 1857.
——Tuomeya fluviatilis Harvey in Smithsonian Contributions to Knowledge10 (2): 64. 1858;
Setchell in Proc. Amer. Acad. Arts & Sci. 25: 53. 1890; Skuja in Acta Horti Bot. Univ. Latv.
14: 3. 1944; Starmach in Flora Slodkowodna Polski. 214. 1977.
美洲托氏藻 Figs. 1–3
Plants are densely branched, monoecious, caespitose, cartilaginous and cylindrical
gametophytes. It ranges in color from blue-green to olive, and plants are about 2.5–5 cm high
(Fig. 1: A). Three to five layers of cortical filaments, dense laterals arising from pericentral
cells, cover the unaxial filament (Fig. 1: C; 3: F). Cortical cells are long cylindrical, 40–50 μm
long, 8.5–9.5 μm in diameter (Fig. 1: D; 3: A). Axial cells are evident in mature branches by
their constrictions. Whorls are not well developed, remote from each other, about 35–40 μm
in diameter (Fig. 1: B). Internodes are about 85–105 μm long. Primary fascicles are 1–3
dichotomously branched, 5–7 cells long, and cells are cylindrical-ellipsoid, 18–20 μm long,
9–11 μm in diameter, with rare terminal hairs. Secondary fascicles are also 1–3
dichotomously branched, and cells similar to the primary fascicles.
Carpogonia are asymmetrical with an irregularly broadened trichogyne attached
obliquely or perpendicularly to a stalk and born on a curved carpogonial branch derived from
basal cells. Carpogonial branches are twisted, 7–10 cells long, and each cell is 2.5–4 μm long,
5 μm in diameter (Fig. 2: B; 3: E). Carpogonia (including the trichogyne) are 45–55 μm long,
10–12 μm in diameter (Fig. 2: D; 3: C). The trichogyne is long, ellipsoid. Carposporophytes
are discretely shaped, globose, 200–250 μm in diameter (Fig. 2: C), and 1(–2) per whorl.
No. 5 FENG et al.: Tuomeya Harvey, a genus of freshwater Rhodophyta newly recorded from China 721














































Fig. 1. Tuomeya americana (Kützing) Papenfuss. A, Habit of frond. B, Part of a frond, showing shape of whorls. C,
The cross section through a node showing an axial cell and numerous layers of cortical cells. D, Numerous cortical
filaments. E, Carposporangia. F, Apical portion of branch with apical cell (arrow).
Ac, axial cell; bc, basal cell; cc, cortical cell; pf, primary fascicle; sf, secondary fascicle.
Acta Phytotaxonomica Sinica Vol. 45 722
































Fig. 2. Tuomeya americana (Kützing) Papenfuss. A, Fascicle with terminated spermatangia. B, Juvenile coiled
carpogonial branch (arrow). C, Carposporophyte, showing carposporangia (arrow). D, Mature carpogonium (arrow).
Cc, cortical cell; pf, primary fascicle; sp, spermatangium.

Carposporangia are ovoid, 15–21 μm in length, 12–15 μm in diameter (Fig. 1: E; 3: D).
Spermatangia are globose, single or double, terminating lateral branches, 6.5–7.5 μm in
diameter (Fig. 2: A; 3: B).
China. Jiangsu (江苏): Xuzhou (徐州) (34°1202.82" N, 117°1546.11" E), collected in
Bajian Spring, on rocks and stones in flowing water, 2006-03-24, J. Feng et al. (冯佳等)
JS2006001 (SXU).
Distribution: Eastern North America from Newfoundland in the north to Alabama and
Louisiana in the south (Kaczmarczyk et al., 1992; Vis et al., 1998; Kapraun et al., 2007) and
South Africa (Borge, 1928).
No. 5 FENG et al.: Tuomeya Harvey, a genus of freshwater Rhodophyta newly recorded from China 723




Fig. 3. Tuomeya americana (Kützing) Papenfuss. A, axial cells and cortical cells; B, fascicle with terminated
spermatangia; C, carpogonial branch with mature carpogonium; D, carposporangia; E, juvenile coiled carpogonial branch;
F, the cross section through a node showing numerous layers of cortical cells. Drawn by S. L. Xie from J. Feng et al.
JS2006001.
Ac, axial cell; bc, basal cell; ca, carpogonium; cb, carpogonial branch; cc, cortical cell; cs, carposporangia; pf, primary
fascicle; sf, second fascicle; sp, spermatangium.
Acta Phytotaxonomica Sinica Vol. 45 724
2.2 Molecular analyses
Sequence variation of rbcL gene within four samples were analyzed (Table 1). Within
the 1282 sequence region, there were 129 variable nucleotide positions, but the sample
(AF029352) is only 721 bp in length (positions 556 to 1276 inclusive, compared with the
sample collected from Xuzhou), and the sample (DQ523253) is missing 50 bp (Fig. 4).

















































Fig. 4. Sequence alignment of rbcL region of the chloroplast DNA for Tuomeya americana populations sampled. A
dash indicates a deletion relative to the Xuzhou collection, and N indicates a missing base.
No. 5 FENG et al.: Tuomeya Harvey, a genus of freshwater Rhodophyta newly recorded from China 725
Table 1 List of samples information and accession numbers of rbcL sequence of Tuomeya americana in
GenBank
Sample Collection information Accession number
1 USA: Beaver River, South Kingston, Rhode Island AF029352
2 USA: Lower Barton Creek, North Carolina AF029159
3 China: Xuzhou, Jiangsu
4 USA: Lower Barton Creek, North Carolina DQ523253

3 Discussion
The genus Tuomeya belongs to Batrachospermaceae, Batrachspermales, Rhodophyta. It
was originally distinguished from the other members of Batrachospermales by its having a
densely branched, cartilaginous, and pseudoparenchymatous thallus with compacted lateral
whorls radiating from a uniseriate axis (Harvey, 1858). Subsequently, Setchell (1890) noted
that the plants appeared to be intermediate between Batrachospermum and Lemanea. Necchi
and Entwisle (1990) proposed that Tuomeya should be reduced to a section of the genus
Batrachospermum, but in 1992, Kaczmarczyk, Sheath and Cole confirmed the previous
classification scheme because Tuomeya differs from Batrachospermum in its
pseudoparenchymatous growth and its carpogonia with obliquely to perpendicularly attached
trichogynes. Moreover, Tuomeya is unique in having gametophyte development from a basal
mass of undifferentiated cells. Kaczmarczyk et al. (1992) also used multivariate
morphometrics and concluded that the genus Tuomeya should be maintained as distinct in
contrast to the proposal of Necchi and Entwisle. We considered that the classification scheme
supported by Kaczmarczyk et al. is much more reasonable.
When the genus Tuomeya was described by Harvey in 1858, T. fluviatilis (specimen
collected by Tuomey in Alabama, USA) was designated as the type species. However, this
taxon had been earlier validated as Baileya americana by Kützing (1857). Papenfuss (1958)
renamed the species as T. Americana based on an older name of Kützing.
The amplified rbcL region of chloroplast DNA of T. americana obtained from Xuzhou is
comprised of 1282 bp and a BLAST search gives close resemblance of this sample with the
others collected from the North America (GenBank accession number AF029159) having
85.57% similarity. Between the population from Xuzhou and North Carolina (DQ523253)
there was 14.51% sequence variation, and in pairwise comparisons of sequence data of 721
bp, there were 95 bp changes (13.18% sequence divergence) between collections from
Xuzhou and the sample (AF029352). However, the sequence divergence values are
0.55%–10.37% among previously published sequence from North America. Therefore, the
divergence among them may result from the biogeographical isolation.
Tuomeya americana was previously known only from North America and South Africa.
It is reported from China (and Asia) for the first time.
Acknowledgements We thank Professor HUA Dong for his kind help in sample collection.
References
Borge O. 1928. Zellpflanzen Ostafrikas, gesammelt auf der Akademischen Studienfahrt 1910. Teil VIII.
Süsswasseralgen. Hedwigia 68: 93–114.
Harvey W H. 1858. Nereis Boreali-Americana. Part III─Chlorospermae. Washington, DC: Smithsonian
Contributions to Knowledge. 138.
Kaczmarczyk D, Sheath R G, Cole K M. 1992. Distribution and systematics of the freshwater genus Tuomeya
(Rhodophyta, Batrachospermacaea). Journal of Phycology 28: 850–855.
Kapraun D F, Bradley K S, Freshwater D W. 2007. Nuclear DNA content variation in the freshwater red algal
orders Batrachospermales and Thoreales (Florideophyceae, Nemaliophycidae). Phycologia 46 (1): 54–62.
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Kumano S. 2002. Freshwater Red Algae of the World. Bristol: BioPress Limited. 238–242.
Kumar S, Tamura K, Nei M. 2004. MEGA 3: Integrated Software for Molecular Evolutionary Genetics
Analysis and Sequence Alignment. Philadelphia: Pennsylvania State University.
Kützing F T. 1857. Tabulae Phycologicae Vol. VII. Nordhausen: 35, plate VII.
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Batrachospermaceae (Rhodophyta). Phycologia 29: 478–488.
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Phaeophyceae and Rhodophyceae. Taxon 7: 104–109.
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isolation of polymerase chain reaction-friendly DNA. Journal of Phycology 29: 251–254.
Setchell W A. 1890. Contributions from the Cryptogamic Laboratory of Harvard University. XII. Concerning
the structure and development of Tuomeya fluviatilis Harv. Proceedings of American Academic Arts
Science 25: 53–68.
Vis M L, Saunders G W, Sheath R G, Dunse K, Entwisle T J. 1998. Phylogeny of the Batrachospermales
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中国淡水红藻一个新记录属——托氏藻属
冯 佳 谢树莲* 姚 戈
(山西大学生命科学与技术学院 太原 030006)

摘要 报道了中国淡水红藻一个新记录属——托氏藻属Tuomeya Harvey。标本采于江苏徐州。该属以
植物体软骨质 , 多层细胞紧密排列组成坚固的皮层 , 果胞枝弯曲等特征 , 区别于串珠藻科
Batrachospermaceae的其他属。除对此种藻类的形态作详细描述外, 还通过rbcL序列比较分析其与北美
地区样本的地理差异。该属先前在加拿大、美国和南非有过报道。
关键词 托氏藻属; 串珠藻科; 串珠藻目; 淡水红藻; rbcL序列; 新记录; 中国