Early stage differentiation of thallus cells ofPorphyra haitanensis (Rhodophyta)

The early stage differentiation of thallus cells ofPorphyra haitanensis T. J. Chang et B. F. Zheng was studied. Protoplasts or single cells were isolated from the blades using enzyme mixture comprising 2% sea snail gut enzyme and 1% cellulase. The isolated protoplasts or single cells were incubated in the MES medium. The cell differentiations were examined under the microscope at intervals after incubation. Four types of cell differentiation, namely, normal, abnormal, carposporangial and spermatorangial, and rhizoidal types, were observed. Since normal cell differentiations occur mostly in small thalli 50 mm in length and middle portions of big thalli 200 mm in length, it is essential to select tissues from these two kinds of thalli essential for commercial production.     

Development of suspended conchocelis ofPorphyra haitanensis (Bangiales, Rhodophyta)

This Mar. 1993 to Aug. 1994 study on suspended conchocelis ofPorphyra haitanensis showed that there were three patterns for development of vegetative filaments: filaments to filaments by “budding”; filaments to sporangial branchlets by “budding”, or cell swelling. There were also three patterms for sporangial branchlet development: vegetatively propagating, changing into conchospores, or dying. Each developmental stage had one or more different developmental directions between vegetative filaments and sporangial branchlets. Developments from conchosporangial branchlets to conchospores were sequential and irreversible. Although sporangial branchlets formed at 29°C could give rise to filaments, they could not propagate as healthily under the same conditions as those formed at 25°C did. Probably the crucial period of plant cell differentiation is in the late stage of sporangial branchlets. In line with the developmental directions of different stages, the authors regulated the development of conchocelis to get ideal different developmental stages materials to obtain very developmentally homogeneous stages, including filaments and sporangial branchlets. Contribution No 3283 from the Institute of Oceanology, Chinese Academy of Sciences. Study supported by the Climbing Project B PD-B6-4-2 of the State Science and Technology Commission of China.     

Studies on color type variants from mutagenized protoplasts ofPorphyra haitanensis Chang et Zheng &P. Yezoensis ueda (rhodophycease)

Isolated protoplasts from thalli ofPorphyra haitanensis andPorphyra yezoensis were treated with colchicine or irradiated by ultraviolet (UV). Several types of color variants were observed among the protoplast offspring. After treatment with colchicine: (1) 0.04–0.09% of red type variants inP. haitanensis were obtained; (2) The rate of red type variants and the variegated chimeral thalli composed of red type and wild type of sectors were 0.31–1.11% inP. yezoensis. After irradiation with UV: (1) 3.5–10.5% of red type variants inP. yezoensis were obtained: (2) 0.5–2.0% of red type variants and the variegated chimeral thalli composed of red type and wild type of sectors were obtained inP. haitanensis. Colchicine and UV’s mutangenic effects onP. yezoensis protoplasts were stronger than those onP. haitanensis protoplasts. The most efficient concentration of colchicine was 0.05%. The optimal length of UV-radiation was 1/2 min (radiation distance 5 cm). The red type variants induced by colchicine treatment grew faster than the wild type thalli. The clones of vegetative propagation from protoplasts of red type variants were still red type thalli. The red type variants will be good materials for genetic studies and improvement ofPorphyra strains.     

Studies on intercropping ofPorphyra haitanensis T. J. Chang et B. F. Zheng with Bay ScallopArgopecten irradians Lamarck

Results of the experiment of northward transplantation ofPorphyra haitanensis showed that intercrop ofP. haitanensis with Bay Scallop is feasible because the growth duration of both of them is about the same in August–December. Full use of cultivating area, lowering its cost and increasing its product per unit area as well as improving the ecological environment are realized during intercrop. Contribution No. 2152 from the Institute of Oceanology, Academia Sinica.     

Study on monospore-like cells fromPorphyra haitanensis

Porphyra haitanensis andP. yezoensis are two mainPorphyra species cultured in China. Their life histories are slightly different. So far we have not observed thatP. haitanensis naturally produces monospores developing into thalli.P. yezoensis produces monospores which directly germinate into young thalli used in cultivation (Zeng, et al., 1985). Some somatic cells inP. yezoensis develop in vitro into monospore-like cells which later grow into young thalli (Lu, 1983). Studies on whether or not somatic cells inP. haitanensis can produce in vitro monospore-like cells that later grow into young thalli is important for understanding its life history and for culturing new varieties.     

Gamma-rays induction of mutation in conchocelis ofPorphyra yezoensis

Free-living conchocelis ofPorphyra yezoensis Ueda (Bangiales, Rhodophyta) were treated with⁶⁰Co-γ rays of different doses (ranging from 100 Gy to 1000 Gy) to induce mutation. Most of the conchocelis maintained the capability of penetrating into shells, growing and forming colonies in shells, but their vitality was seriously impaired by the irradiation of γ-rays. A few conchocelis pigments were mutagenized directly into different color pigment mutants whose progeny-conchospores and foliose thalli had the same colors. However, some irradiated conchocelis did not show the change in color at the conchocelis stage. The pigment mutation could be observed only after the conchospores of these conchocelis had germinated into young foliose thalli. Irradiation of low dose (100 Gy) promoted the growth of thallus and many with altered morphology were observed. Conchospores of the irradiated conchocelis attached to the culture nets were cultured in the sea, and growth of these progenies was observed and measured.     

Effect of cytokinins and auxins on the growth of free-living conchocelis ofPorphyra yezoensis

IAA 3-Indolylacetic acid, NAA a-Naphthylacetic acid and cytokinins in PESI culture medium were used in a study on the effects of plant hormones on the growth of free-living conchocelis ofPorphyra yezoensis which showed that its growth in medium with cytokinins, IAA and NAA was more rapid than that in medium with non—phytohormones; that the optimal concentrations for promoting growth were 10 μg/L for IAA and ZA (Zeatin), and 0.1 μg/L for BA 6-Benzyl amino purine and KIN 6-Furfurylamino- purine. Mix use of NAA, IAA and cytokinins, NAA/ZA 1–1000/1 μg/L, NAA/BA 10/1-1000 μg/L, NAA/KIN 1/1-1000 μg/L promoted growth. IAA/ZA 0.1-1/0.1-1 μg/L; IAA/BA 0.1-1/0.1-10 μg/L IAA/KIN 1/0.1-1000 μg/L also promoted growth. Contribution No. 2335 from the Institute of Oceanology, Chinese Academy of Sciences. Contribution No. 94 from the Experimental Marine Biology Lab Qingdao, China. The research was supported by a grant from the Chinese Academy of Sciences.     

Subunit composition and chromophore content of R-phycoerythrin fromPorphyra haitanensis

R-phycoerythrin fromPorphyra haitanensis exists in two aggregation states with different molecular weights. A more highly aggregated form, RPE I, was chromatographed on Bio-Rex 70 column with urea solution (pH 3.0) as eluent, and the molecular weights of the 3 subunits (α, β, γ) obtained were determined on SDS-PAGE at 18000, 19200 and 30000, respectively. α subunit carried two phycoerythrobilin (PEB); β subunit, three PEB and one phycourobilin (PUB); γ subunit, one PEB and three PUB chromophores. The molar ratio of α, β, and γ subunits of RPE I was 6: 6: 1, and their subunit composition was confired to be (αβ)₆γ on account of the molecular weight of RPE I, 232000. A lower aggregated form, RPE II, contained α and β subunits similar to those of RPE I, but its subunit composition was the (αβ) monomer of RPE. Contribution No. 2108 from the Institute of Oceanology, Chinese Academy of Sciences     

Microalgae cultivation in a tubular bioreactor and utilization of their cells

In this study on the possiblities of microalgae technology as an option for CO₂ mitigation, many microalgae were isolated from seawater. Some species of the isolates,Chlamydomonas sp. strain YA-SH-1, which accumulates starch in cells under light and ferment ethanol in dark and anaerobic condition, was grown outdoors by using 50-L tubular bioreactors in batch cultivation and harvested. Using these cells, the performance of ethanol production was examined quantitatively in a 0.5-L scale fermentor. Another species,Tetraselmis sp. strain Tt-1, was cultivated in a semi-batch manner by a similar type of tubular bioreactor indoors and examined for its utilization. Tests showed these cells could be used as partial substitute for wood and kenaf pulp for processing into paper. With the idea of making microalgae produce cellulose by genetic engineering in their minds, the authors studied the structure of bacterial cellulose synthase genes and the low temperature-induced, reversible flocculation in a thermophilic blue green alga (Cyanobacterium),Synechocystis vulcanus in order to examine the feasibility of using these genes as gene source and the cynanobacterium as host.

     

Identification and bioinformatics analysis of micro RNAs from the sporophyte and gametophyte of Pyropia haitanensis

Pyropia haitanensis(T.J.Chang et B.F.Zheng) N.Kikuchi et M.Miyata( Porphyra haitanensis) is an economically important genus that is cultured widely in China.P.haitanensis is cultured on a larger scale than Pyropia yezoensis,making up an important part of the total production of cultivated Pyropia in China.However,the majority of molecular mechanisms underlying the physiological processes of P.haitanensis remain unknown.P.haitanensis could utilize inorganic carbon and the sporophytes of P.haitanensis might possess a PCK-type C 4-like carbon-fixation pathway.To identify micro RNAs and their probable roles in sporophyte and gametophyte development,we constructed and sequenced small RNA libraries from sporophytes and gametophytes of P.haitanensis.Five micro RNAs were identified that shared no sequence homology with known micro RNAs.Our results indicated that P.haitanensis might posses a complex s RNA processing system in which the novel micro RNAs act as important regulators of the development of different generations of P.haitanensis.     

Formation of primary pit connection during conchocelis phase of Porphyra yezoensis （Bangiophyceae, Rhodophyta）

1 INTRODUCTION Pit connection is an important feature in Rhodophyta and significant in algal phylogeny. Various documents have illustrated the existence of pit-connection in red alga previously (Migita, 1967; Ramus 1969a, b; Bourne et al., 1970; Lee and F…     

On microbial community of Pyropia haitanensis by metagenomic analysis

Microorganisms plays an important role in the growth of Pyropia haitanensis. To understand the structural and functional diversity of the microorganism community of P. haitanensis(PH40), the associated metabolic pathway network in cluster of orthologous groups(COG) and Kyoto Encyclopedia of Genes and Genomes(KEGG), and carbohydrate-active enzymes(CAZymes) were explored in metagenomic analysis. DNA extraction from gametophytes of P. haitanensis was performed first, followed by library construction, sequencing, preprocessing of sequencing data, taxonomy assignment, gene prediction, and functional annotation. The results show that the predominant microorganisms of P. haitanensis were bacteria(98.98%), and the phylum with the highest abundance was Proteobacteria(54.64%), followed by Bacteroidetes(37.92%). Erythrobacter(3.98%) and Hyunsoonleella jejuensis(1.56%) were the genera and species with the highest abundance of bacteria, respectively. The COG annotation demonstrated that genes associated with microbial metabolism was the predominant category. The results of metabolic pathway annotation show that the ABC transport system and two-component system were the main pathways in the microbial community. Plant growth hormone biosynthesis pathway and multi-vitamin biosynthesis functional units(modules) were the other important pathways. The CAZyme annotation revealed that the starch might be an important carbon source for microorganisms. Glycosyl transferase family 2(GT2) and glycosyl transferase family 3(GT3) were the highly abundant families in glucoside transferase superfamily. Six metagenome-assembled genomes containing enzymes involved in the biosynthesis of cobalamin(vitamin B 12) and indole-3-acetic acid were obtained by binning method. They were confirmed to belong to Rhodobacterales and Rhizobiales, respectively. Our findings provide comprehensive insights into the microorganism community of Pyropia.     

Comparative studies on structural feature of agar polysaccharides fromPorphyra haitanensis grown in south and north China

The structural feature of agar polysaccharides fromPorphyra haitanensis grown in south China and transplanted to the north was investigated by fractionation on DEAE—Sephadex A 50, chemical analysis, and infrared and¹³C-NMR spectroscopy. The agars composed mainly of charged molecules were eluted from DEAE—Sephadex A 50 with 1.0 mol/L NaCl solution from the southernP. haitanensis and with 0.5 mol/L NaCl from the northern one. The¹³C-NMR spectra showed that agarobiose [(1→3)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-α-L-galactopyranose] and the biological precursor of agarobiose [(1→3)-β-D-galactopyra nosyl-(1→4)-6-sulfate-α-L-galactopyranose] were the major disaccharide repeating units in the charged fractions. The content of the biological precursor in the agar polysaccharides from southernP. haitanensis was higher than that in the northern one, the content of the biological precursor extracted from cold water was higher than that from hot water, and the content of 6-OMe-D-galactose in the southernP. haitanensis polysaccharides was higher than in the northern one. This distinct difference will be of significance for further study of the physiological characters ofP. haitanensis. Contribution No. 1849 from the Institute of Oceanology, Academia Sinica.     

Study on gametophyte vegetative growth ofUndaria pinnatifida and its applications

When cultured under certain environmental conditions (25°C, light intensity 80 μmol/m²·s, LD 12/12, in enriched seawater medium with 7×10⁻⁴ mol/L NO₃−N, 1.56×10⁻⁴ mol/L, PO₄−P and supplements of other elements like Mn, Fe, I, etc.), male and female gametophytes ofU. pinnatifida kept growing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. The empirical formulaG _m=G _o·3^m was established to estimate the output of vegetative gametophytes. Vigorous vegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, when the temperature was lower than 25°C and other environmental factors were kept optimal. The sufficient supply of gametophyte cells provided enough seeds for raisingUndaria sporelings on production scale. Controlled cross-breeding experiments using selected male and female gametophyte clones which increase their cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes from the cross-breeding had almost the same length and width increase rates as those of the control. The fact that vegetative gametophytes can be purposely selected, propagated quickly, cross-bred, with the resulting sporophytes having almost the same characteristics leads to a new way to select desiredUndaria strains for long time use without losing the desired economic characteristics. Contribution No. 2696 from the Institute of Oceanology, Chinese Academy of Sciences. Supported by National Natural Science Foundation of China.     

On the transplantation and cultivation ofKappaphycus alvarezii in China

A 2-year study onKappaphycus alvarezii (Doty) Doty introduced to Hainan Island from the Philippines in 1985 showed promising results. The average daily growth in weight reached 10% at a favourable temperature of about 26°C. Experimental results showed that timely cutting of the plant was an effective way to obtain new cuttings for cultivation and accelerate growth. New cuttings 0.05 kg in weight are suggested to be used as “seeds” and the old plant should be harvested. At present, artificial cultivation with a type of underwater raft applicable in places where there is strong wind will expand cultivation to more regions in Hainan Province. This paper was originally published in Chinese inOceanologia et Limnologia Sinica 19(5): 410–418, 1988. The plant under discussion wasEucheuma alvarezii Doty which was previously calledE. striatum in the article, and which now becomesKappaphycus alvarezii (Doty) Doty. To the original title, “in China” was added. Only the essence of the original article was presented.     

Estimation of vegetative surface albedo in the Kushiro Mire with Landsat TM data

A method has been developed for estimating the filtered narrow band surface albedo with Landsat/TM data. In this method, the surface albedo from filtered range of Landsat/TM is converted to the surface albedo with unfiltered spectral range. The atmospheric effects on each channel are systematically different, because of the different spectral behavior of atmospheric parameters. As a result, in this study, atmospheric correction has been done respectively in different parameters for visible and infrared channels. The surface albedos of the Kushiro Mire gotten with this method were compared with the observed data there. The results show that the satellite inferred albedos have a good agreement to the diurnal mean of ground observed albedos with 3% systematic error. There is a seasonal variation of albedo in high and low mires, the albedo decreased gradually from April to July and reached its minimum in July, further it rose gradually from August to October. It is also clear that there is a characteristic pattern of surface distribution according to the vegetation types of this area. The average surface albedos of each type of community are 0.164 for Sphagnum, 0.175 for Carex, 0.179 for Pragmites and 0.166 for Alnus. In the other words, the albedo in high mire (mainly covered by Sphagnum) is lower than that in low mire (mainly covered by Phragmites and Carex).     

Identification of potential internal control genes for real-time PCR analysis during stress response in Pyropia haitanensis

Pyropia haitanensis has prominent stress-resistance characteristics and is endemic to China. Studies into the stress responses in these algae could provide valuable information on the stress-response mechanisms in the intertidal R hodophyta. Here, the ef fects of salinity and light intensity on the quantum yield of photosystem II in P y. haitanensis were investigated using pulse-amplitude-modulation fluorometry. Total RNA and genomic DNA of the samples under dif ferent stress conditions were isolated. By normalizing to the genomic DNA quantity, the RNA content in each sample was evaluated. The c DNA was synthesized and the expression levels of seven potential internal control genes were evaluated using q RT-PCR method. Then, we used ge Norm, a common statistical algorithm, to analyze the q RT-PCR data of seven reference genes. Potential genes that may constantly be expressed under dif ferent conditions were selected, and these genes showed stable expression levels in samples under a salinity treatment, while t ubulin, glyceraldehyde-3-phosphate dehydrogenase and actin showed stability in samples stressed by strong light. Based on the results of the pulse amplitude-modulation fluorometry, an absolute quantification was performed to obtain gene copy numbers in certain stress-treated samples. The stably expressed genes as determined by the absolute quantification in certain samples conformed to the results of the ge Norm screening. Based on the results of the software analysis and absolute quantification, we proposed that e longation factor 3 and 18 S ribosomal RNA could be used as internal control genes when the P y. haitanensis blades were subjected to salinity stress, and that α-tubulin and 18 S ribosomal RNA could be used as the internal control genes when the stress was from strong light. In general, our findings provide a convenient reference for the selection of internal control genes when designing experiments related to stress responses in Py. haitanensis.     

The vertical structure of the vegetative canopy of the brown algae Cystoseira (Black Sea)

In the coastal ecosystems of the Black Sea, macrophytobenthos and, in particular, the association of Cystoseira crinite, C. barbata, Cladostephus verticillatus, and Corallina mediterranea, with its thick vegetative canopy(VC), is the key contributor to primary production(PP). Though the vertical structure of the canopy, formed by the algal association, is of principal importance to the PP level, this subject has been long-neglected by researchers. The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast. Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55–60 cm deep) sites of Sevastopol Bay(Crimean Peninsula). Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually, per horizontal surface unit, at each height( Z). The study shows that: 1) the VC is characterized by unimodal vertical distribution of biomass, with maximum estimate in the lower part, where the biomass increases to 85% of the total biomass; 2) a series of single-peaked curves reliably describes the unimodal distribution of the biomass; thalli of dif ferent age groups are found along the canopy pro?le; and 3) algae found in epiphytic synusia prefer inhabiting the upper part of the VC. The role of environmental factors(seawater turbulence and solar radiation) is discussed in reference to the formation of the vertical structure, made up of the associations of the brown algae Cystoseira.     

Effects of elevated CO2 on the photosynthesis and nitrate reductase activity of Pyropia haitanensis (Bangiales,Rhodophyta) grown at different nutrient levels

Pyropia haitanensis,a commercially important species,was cultured at two CO2 concentrations(390×10- 6 and 700×10-6(parts per million)) and at low and high nutrient levels,to explore the effect of elevated CO2 on the species under nutrient enrichment. Results show that in CO2-enriched thalli,relative growth rate(RGR) was enhanced under nutrient enrichment. Elevated CO2 decreased phycobiliprotein(PB) contents,but increased the contents of soluble carbohydrates. Nutrient enrichment increased the contents of chlorophyll a(Chl a) and PB,while soluble carbohydrate content decreased. CO2 enrichment enhanced the relative maximum electronic transport rate and light saturation point. In nutrient-enriched thalli the activity of nitrate reductase(NRA) increased under elevated CO2. An instantaneous pH change in seawater(from 8.1 to 9.6) resulted in reduction of NRA,and the thalli grown under both elevated CO2 and nutrient enrichment exhibited less pronounced reduction than in algae grown at the ambient CO2. The thermal optima of NRA under elevated CO2 and/or nutrient enrichment shifted to a lower temperature(10–15°C) compared to that in ambient conditions(20°C). We propose that accelerated photosynthesis could result in growth increment. Nassimilation remained high in acidified seawater and refl ected increased temperature sensitivity in response to elevated CO2 and eutrophication.     

Seaweed cultivation: Traditional way and its reformation

INTRODUCTIONSeaweedcultivationisthemosteffectivewayforobtaininglargeamountofseaweedproducts.Thoughseaweedcultivationhasahistoryofonlyafewdecades,itsdevelopmentisfast (Fei,1 996) .Thetotalproductionofcultivatedseaweedatpresentisabout 62 50× 1 0 3tonsfreshweight,ofwhichLaminariaaccountsfor 3 1 0 0× 1 0 3tons,Undaria 2 2 0 0x 1 0 3tons,Porphyra 750× 1 0 3tons,Gracilariasp .1 0 0× 1 0 3tons,EucheumaandKappaphycus 1 0 0× 1 0 3tons,otherkindofseaweeds 1 0 0× 1 0 3tons.Theestimatedtotal…