<i>Olpidiopsis</i> sp., an oomycete from Madagascar that infects <i>Bostrychia</i> and other red algae: Host species susceptibility

West, John A.,Klochkova, Tatyana A.,Kim, Gwang Hoon,Loiseaux-de Goë,r, Susan Blackwell Publishing Asia 2006 Phycological research Vol.54 No.1

<P>SUMMARY</P><P><I>Olpidiopsis</I> sp. (Oomycota) was cultured with its original host <I>Bostrychia moritziana</I> (Sonder ex Kützing) J. Agardh from Madagascar. Bean-shaped zoospores with two heterokont flagella attached to the host cell wall surface and in 2 days host cells began collapsing and one or more syncytia developed in each infected cell. Zoospores were cleaved and an exit tube with a small plug was formed. Complete development and zoospore discharge occurred in 3 days. Infection occurred in cells of polysiphonous branches, monosiphonous branches, rhizoids and reproductive stichidia. Dead cells of plants treated with microwave were not infected. Susceptibility was variable in other <I>Bostrychia</I> species from different countries. <I>Bostrychia moritziana</I> (Sonder ex Kützing) J. Agardh<I>,</I> and <I>Bostrychia radicans</I> (Montagne) Montagne from Madagascar were susceptible but one <I>Bostrychia tenella</I> (J. V. Lamouroux) J. Agardh isolate from Madagascar was susceptible and two were not. <I>B. radicosa</I> (Itono) J. A. West, G. C. Zuccarello et M. Hommersand isolates from Madagascar, Thailand, Australia and New Caledonia were susceptible but an isolate from Malaysia was not. <I>B. radicans</I> isolates from Mexico and Brazil were non-susceptible as were <I>Bostrychia flagellifera</I> Post, <I>Bostrychia harveyi</I> Montagne, <I>Bostrychia montagnei</I> Harvey, <I>Bostrychia simpliciuscula</I> Harvey ex J. Agardh<I>, Bostrychia tenuissima</I> R. J. King et Puttock<I>, Stictosiphonia intricata</I>(Bory de Saint-Vincent) P. C. Silva, <I>Stictosiphonia kelanensis</I> (Grunow) R. J. King et Puttock and <I>Stictosiphonia tangatensis</I> (Post) R. J. King et Puttock, <I>Lophosiphonia</I> sp., <I>Neosiphonia</I> sp. and <I>Polysiphonia</I> spp. isolates were also non-susceptible. Many non-susceptible strains showed initial cell-collapse followed by rapid wound-repair cell formation without syncytia or sporangia developing. <I>Caloglossa leprieurii</I> (Montagne) G. Martens from Madagascar showed cell-collapse and wound-repair in periaxial cells, but wing cells died and became purple without wound-repair. <I>Caloglossa ogasawaraensis</I> Okamura and <I>Caloglossa postiae</I> M. Kamiya et R. J. King had no symptoms of infection. <I>Dasysiphonia chejuensis</I> I. K. Lee et J. A. West was not infected. Surprisingly, the conchocelis phase but not the blade phase of <I>Porphyra pulchella</I> J. A.West, G. C. Zuccarello and <I>Porphyra suborbiculata</I> Kjellman was infected. The conchocelis of <I>Porphyra tenera</I> Kjellman and <I>Porphyra linearis</I> Greville were infected but no blade stages were tested. <I>Porphyra miniata</I> (C. Agardh) C. Agardh and <I>Porphyra dentata</I> Kjellman conchocelis were not infected. <I>Bangia atropurpurea</I> (Roth) C. Agardh gametophyte filaments were not infected. Other red, brown and green algae were not infected. Time lapse videomicroscopy of development and spore release was done.</P>

Rosenvingea orientalis (Scytosiphonaceae, Phaeophyceae) from Chiapas, Mexico: life history in culture and molecular phylogeny

John A. West,Giuseppe C. Zuccarello,Francisco F. Pedroche,Susan Loiseaux de Goër 한국조류학회I 2010 ALGAE Vol.25 No.4

The genus Rosenvingea is well known in the tropics. Four species have been reported from Pacific Mexico: R. floridana,R. antillarum, R. intricata and R. sanctae-crucis. We collected a plant (Boca del Cielo, Chiapas) that we identified as Rosenvingea orientalis, a species not previously reported from Pacific Mexico. We were able to characterize the life cycle of this species for the first time in laboratory culture. It reproduced exclusively by plurilocular sporangia (plurangia). The mature plants were up to 6 cm long with cylindrical to compressed fronds (to 2 mm wide) with dichotomous branches in the upper half of the thallus. The medulla was hollow with 2-3 layers of large inflated colourless cells at the periphery. The cortex was comprised of 1 layer of small cells, each with a single chloroplast and pyrenoid. Linear plurangial sori with phaeophycean hairs formed along the mature fronds. Zoospore germlings developed into prostrate filamentous systems, each with a single phaeophycean hair that gave rise to a single erect shoot with multiple hairs arising near the tip. Molecular phylogeny using the psaA gene placed this isolate within the Scytosiphonaceae. It does not confirm the exact identification of R. orientalis, although its placement close to other Rosenvingea sequences was confirmed and morphological evidence supports its placement in R. orientalis. Our culture investigations indicated that it has an asexual life cycle. Further collections are needed to resolve the full generic and specific relationships of Rosenvingea and related taxa, and their reproductive patterns.

Monosiphonous growth and cell-death in an unusual Bostrychia (Rhodomelaceae, Rhodophyta): B. anomala sp. nov.

John A. west,Susan Loiseaux de Goër,Giuseppe C. Zuccarello 한국조류학회I 2013 ALGAE Vol.28 No.2

A morphologically distinct lineage within the Bostrychia moritziana-B. radicans species complex is described as a new species. Bostrychia anomala has thalli with branched monosiphonous filaments with apical cell divisions. The species has terminal tetrasporangial stichidia, each subtending cell bearing tetrasporangia with 2 cover cells. Discharged spores divide transversely, the lower cell first forming a narrow rhizoid and the upper cell forming a monosiphonous shoot. Females have subterminal procarps and males have terminal spermatangial stichidia. Carposporophytes are spherical. Isolates in culture show a pattern of cell death not associated with injury, reminiscent of programmed cell death. Bostrychia anomola shows cell death at intervals along the filaments resulting in division of adjacent cells on either side of the dead cell re-joining the filament; cell division of only one adjacent cell resulting in branching at that site; or filaments fragmenting at the cell death point with adjacent cells forming new apical cells, a means of thallus propagation. The cell death pattern could be a method of filament propagation in the mangrove environment where sexual reproduction is rare.

Observations on some mangrove-associated algae from the western Pacific (Guam, Chuuk, Kosrae, and Pohnpei)

John A. west,Mitsunobu Kamiya,Susan Loiseaux de Goër,Ulf Karsten,Giuseppe C. Zuccarello 한국조류학회I 2013 ALGAE Vol.28 No.3

The mangrove algal flora of Guam and the Federated States of Micronesia has been poorly explored. We add to our knowledge of this region by observations of collections from these regions. This paper presents new and additional records of: Rhodophyta-Acrochaetium globosum, Colaconema sp., Caulacanthus indicus, Bostrychia moritziana / B. radicans, B. radicosa, B. simpliciuscula, B. kelanensis and B. tenella, Murrayella periclados, and Caloglossa ogasawaraensis; Chlorophyta-Boodleopsis carolinensis; and Phaeophyceae-Dictyota adnata, Dictyotopsis propagulifera, and Canistrocarpus cervicornis. Most specimens were cultured to investigate their reproductive biology and many specimens were further identified using molecular data. Low molecular weight carbohydrates (dulcitol, sorbitol, and digeneaside) were identified in samples of B. radicosa and B. simpliciuscula. We also present data on manganese-rich deposits found on B. simpliciuscula and B. tenella in culture, possibly formed by epiphytic bacteria.

Thorea indica sp. nov. (Thoreales, Rhodophyta) from Uttar Pradesh, India

Orlando Necchi Jr.,Monica O. Paiano,John A. west,E. K. Ganesan,Susan Loiseaux de Goër 한국조류학회I 2015 ALGAE Vol.30 No.4

Thorea indica sp. nov. is described from the Sai River, Uttar Pradesh, India (26°39′00.7″ N, 80°47′38.3″ E). Its classification is based on molecular sequences of the plastid-encoded RuBisCO large-subunit gene, rbcL and the barcode region of the mitochondrial encoded cytochrome c oxidase subunit 1, cox1, and morphological data. The sequence analyses confirm a new species of Thorea. The cox1 barcode sequence had 90.4-90.8% identity with Thorea sp. from Australia and Thorea hispida from Hawaii and China. Based on rbcL sequences the Indian specimen was positioned in a major clade with high support (>95 bootstrap and 0.95 posterior probability) containing two other species: T. okadae from Japan and T. hispida from the continental USA, Hawaii, the UK, and China. The divergences among these sequences were T. indica vs. T. okadae (2.8%) and T. indica vs. T. hispida (2.9-3.4%). The comparison of morphological characters of Thorea from India was not conclusive due to the inadequate descriptions in previous reports: most specimens reported as T. hispida fit within the circumscription of T. indica as described here. The previous report of T. siamensis from the Sai River is incorrect and the specimens fit within our description of T. indica. Thorea indica and T. okadae can be distinguished by minor morphometric characters and sexuality (dioecious vs. monoecious).

Viator vitreocola gen. et sp. nov. (Stylonematophyceae), a new red alga on drift glass debris in Oregon and Washington, USA

Gayle I. Hansen,John A. West,윤환수,Christopher D. Goodman,Susan Loiseaux de Goër,Giuseppe C. Zuccarello 한국조류학회I 2019 ALGAE Vol.34 No.2

A new encrusting red alga was found growing abundantly on glass debris items that drifted ashore along the coasts ofOregon and Washington. These included discarded fluorescent tubes, incandescent light bulbs, capped liquor bottles,and ball-shaped fishing-net floats. Field collections and unialgal cultures of the alga revealed that it consisted of twomorphological phases: a young loosely aggregated turf and a mature consolidated mucilaginous crust. The turf phaseconsisted of a basal layer of globose cells that produced erect, rarely branched, uniseriate to multiseriate filaments up to500 μm long with closely spaced cells lacking pit-plugs. These filaments expanded in size from their bases to their tipsand released single cells as spores. At maturity, a second phase of growth occurred that produced a consolidated crust,up to 370 μm thick. It consisted of a basal layer of small, tightly appressed ellipsoidal-to-elongate cells that generateda mucilaginous perithallial matrix containing a second type of filament with irregularly spaced cells often undergoingbinary division. At the matrix surface, the original filaments continued to grow and release spores but often also eroded. Individual cells, examined using confocal microscopy and SYBR Green staining, were found to contain a central nucleus,a single highly lobed peripheral chloroplast without a pyrenoid, and numerous chloroplast nucleoids. Morphologicaldata from field and culture isolates and molecular data (rbcL, psbA, and SSU) show that this alga is a new genus and specieswhich we name Viator vitreocola, “a traveller on glass.”

Erythrolobus australicus sp. nov. (Porphyridiophyceae, Rhodophyta): a description based on several approaches

양은찬,John A. West,Joe Scott,윤환수,Akiko Yokoyama,Ulf Karsten,Susan Loiseaux de Goër,Evguenia Orlova 한국조류학회I 2011 ALGAE Vol.26 No.2

The unicellular marine red alga Erythrolobus australicus sp. nov. (Porphyridiophyceae) was isolated into laboratory culture from mangroves in Queensland and New South Wales, Australia. The single multi-lobed red to rose-red plastid has more than one pyrenoid and lacks a peripheral thylakoid. Arrays of small electron dense globules occur along the thylakoids. The nucleus is peripheral with a central to eccentric nucleolus. Each Golgi body is associated with a mitochondrion. The spherical cells are positively phototactic with slow gliding movement. The psaA + psbA phylogeny clearly showed that E. australicus is a distinct species, which is closely related to E. coxiae. The chemotaxonomically relevant and most abundant low molecular weight carbohydrate in E. australicus is floridoside with concentrations between 209and 231 μmol g^(-1) dry weight. Traces of digeneaside were also detected. These various approaches help to understand the taxonomic diversity of unicellular red algae.

On the genus Rhodella, the emended orders Dixoniellales and Rhodellales with a new order Glaucosphaerales (Rhodellophyceae, Rhodophyta)

Joe Scott,Eun Chan Yang,John A. West,Akiko Yokoyama,Hee Jeong Kim,Susan Loiseaux de Goër,Charles J. O’Kelly,Evguenia Orlova,김수연,Jeong Kwang Park,윤환수 한국조류학회I 2011 ALGAE Vol.26 No.4

The marine unicellular red algal genus Rhodella was established in 1970 by L. V. Evans with a single species R. maculata based on nuclear projections into the pyrenoid. Porphyridium violaceum was described by P. Kornmann in 1965 and transferred to Rhodella by W. Wehrmeyer in 1971 based on plastid features and the non-parietal position of the nucleus. Molecular and fine structural evidences have now revealed that Rhodella maculata and R. violacea are one species, so R. violacea has nomenclatural priority and the correct name is Rhodella violacea (Kornmann) Wehrmeyer. The status of families within Rhodellophyceae was examined. The order Dixoniellales and family Dixoniellaceae are emended to include only Dixoniella and Neorhodella. The order Rhodellales and family Rhodellaceae are emended to include Rhodella and Corynoplastis. Glaucosphaera vacuolata Korshikov and the Glaucosphaeraceae Skuja (1954) with an emended description are transferred to the Glaucosphaerales ord. nov.