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1.
The wild Porphyra yezoensis collected from the Qingdao coast was used to prepare protoplasts by enzyme digestion. The pure line was constructed by cultivating the protoplasts. The 18S rDNA of the P. yezoensis pure line was cloned and sequenced. Sequence analysis was executed for this sequence and other 22 sequences retrieved from GenBank. A phylogenetic tree was constructed using the neighbor-joining method. The results revealed a high diversity of 18S rDNA sequences in genus Porphyra and the considerable variation of 18S rDNA sequences in different strains of the same species P. yezoensis and P. tenera. Significant difference of 18S rDNA sequence was observed between P. yezoensis from Qingdao, China, and the two strains of P. yezoensis from Japan, but the three strains of P. yezoensis formed a stable clade in the phylogenetic tree. These results indicate the possibility of interspecies and intraspecies discrimination of Porphyra using the 18S rDNA sequences. 相似文献
2.
GONG Qianhong) YU Wengong) * DAI Jixun) LIU Hongquan) ) XU Rifu) GUAN Huashi) and PAN Kehou) ) College of Medicine Pharmaceutics Ocean University of China Qingdao P. R. China ) College of Marine Life Sciences Ocean University of China Qingdao P. R. China ) College of Fisheries Ocean University of China Qingdao P. R. China 《中国海洋大学学报(英文版)》2007,6(1):21-25
1 Introduction Porphyra yezoensis is one of the most widely con-sumed and cultivated seaweeds in the world. Over the past decades, much effort has been made in improving the cultured stocks and developing breeding techniques of alga. At present, nuclear transformation systems of eu-karyotic algae such as green unicellular alga Chlamydo-monas reinhardii (Rochaix and Dillewijn, 1982), diatom Phseodactylum tricornutum (Lioudmila et al., 2000) and simple multicellular green alga Volvox carteri (… 相似文献
3.
严兴洪 《中国海洋湖沼学报》1993,(3)
Isolated protoplasts from thalli of Porphyra haitanensis and Porphyra 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 in P. 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 6.31- 1.11% in P. yezoensis. After irradiation with UV: (1) 3.5- 10.5% of red type variants in P. 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 in P. haitanensis. Colchicine and UV's mutangenic effects on P. yezoensis protoplasts were stronger than those on P. 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 tr 相似文献
4.
We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four species of algae:Gracilaria textorii,Ulva pertusa,Laminaria japonica,and Polysiphonia urceolata.The isolated strains of bacteria can be divided into two groups:Halomonas and Vibrio,in physiology,biochemical characteristics and 16S rDNA sequence analyses.The phylogenetic tree constructed based on ... 相似文献
5.
The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA of three cultivated strains of Porphyra haitanensis thalli(NB,PT and ST) were amplified,sequenced and analyzed.In addition,the phylogenic relationships of the sequences identified in this study with those of other Porphyra retrieved from GenBank were evaluated.The results are as follows:the sequences of the ITS and 5.8S rDNA were essentially identical among the three strains.The sequences of ITS1 were 331 bp to 334 bp,while those of the 5.8... 相似文献
6.
An improved method of PCR in which the small segment of conchocelis is amplified directly without DNA extraction was used to amplify a RUBISCO intergenic spacer DNA fragment from nine species of red algal genus Porphyra(Bangiales,Rhodophyta),including Porphyra yezoensis(Jiangsu,China),P.haitanensis(Fujian,China),P.oligospermatangia(Qingdao,China),P.katadai(Qingdao,China),P.tenera(Qingdao,China),P.suborboculata(Fujian,China),P.pseudolinearis(Kogendo,Korea),P.linearis(Devon,England),and P.fallax(Seattle,USA).... 相似文献
7.
We collected nine Enteromorpha specimens from the coast of Yantai and evaluated their diversity based on analyses of their ITS （internal transcribed spacer） and 5S rDNA NTS （non-transcribed spacer） sequences. The ITS sequences showed slight nucleotide divergences between Enteromorpha linza and Enteromorpha prolifera. In contrast, multiple highly variable regions were found in the ITS region of Enteromorpha flexuosa. In general, there were more variable sites in the NTS region than in the ITS region in the three species. The variations in 5S rDNA NTS sequences indicated that the molecular diversity of Enteromorpha from the coast of Yantai is very high. However, a phylogenetic tree constructed using 5S rDNA NTS sequence data indicated that genetic differences were not directly related to geographical distribution. 相似文献
8.
Nematode Diversity of Qingdao Coast Inferred from the 18S Ribosomal RNA Gene Sequence Analysis 总被引：1，自引：0，他引：1
SHEN Xiquan YANG Guanpin LIU Yongjian 《中国海洋大学学报(英文版)》2007,6(2):132-136
The 18S ribosomal DNA gene （18S rDNA） sequences （approxtmately 1300 bp in length） were amplified from the DNA extracted from the free-living marine nematodes collected from the inter-tidal sediment of Qingdao coast in bulk with nematode specific primers. The PCR products were cloned, re-amplified, digested with Rsa I and Hin61 restriction endonucleases and separated in agarose gel. Among 17 restriction fragment length types, types 1, 2 and 6 covered 61.2%, 14.4% and 9.3% of the clones analyzed, respectively, while the remaining 14 only covered 21 clones, which accounted for 15.1% of the total. Twenty-four representative clones were sequenced and phylogenetically analyzed by referring to those currently available in RDP and GenBank databases. Although it was hard to assign these sequences to known species or genera due to the lack of the 18S rDNA sequence data of known marine free-living nematodes, the obtained sequences were assigned to the nematodes of Adenophorea. Among them, twelve sequences were close to Pontonema vulgate and Adoncholaimus sp., four to Daptonema procerus and two （identical） to Enoplus brews. Our results showed that free-living marine nematode diversities could be determined by PCR retrieving and analysis of the 18S rDNA sequences and an 18S rDNA sequence could be assigned to a species or a genus only if the 18S rDNA sequences of the free-living marine nematodes were accumulated to some extent. 相似文献
9.
During a survey for marine microalgal resources, we isolated a rare marine euglenoid from the coastal waters of Qingdao, China in 2009, and established a pure culture. Electron microscopic and molecular phylogenetic (18S rDNA and 16S rDNA sequences) analyses revealed a close affinity with Eutreptiella gymnastica, a bloom-forming species. Different culture conditions were monitored to understand optimal E. gymnastica growth characteristics. The optimal growth conditions in a batch culture of this isolate were 20°C, 160 μmol photons/(m2×s) of white light, and a salinity of 10-31. Nutrient experiments demonstrated that growth increased dramatically with a phosphorus concentration greater than 72 μmol/L. Understanding the effect of culture conditions on E. gymnastica may help understanding the blooming mechanism of this alga in its natural environment. 相似文献
10.
Modified carbol fuchsin staining method was successfully introduced into the karyotype analyses of marine algae, in-cluding Porphyra, Undaria pinnatifida and Laminaria japonica. Haploid chromosomes were numbered clearly in the vegetative, spermatangial and conchosporangial cells of P. haitanensis and P. yezoensis. Diploid chromosomes were observed and numbered in immature conchosporangial cells of P. haitanensis and P. yezoensis. Pit-connections of Porphyra were also clearly demonstrated. Prophase chromosomes of conchocelis cells were also clearly stained with modified carbol fuchsin. One molar per liter hydrochloric hydrolysis at 60℃ for 7-8min is necessary for getting transparent cytoplasm for conchosporangial karyotype analysis of Porphyra. Staining effects of the three methods using iron alum acetocarmine, aceto-iron-haematoxylin-chloral hydrate and modified carbol fuchsin were compared on the vegetative, sperrnatangial and conchosporangial cells of Porphyra and the gametophytes of U. pinnati-fida and L. japonica. Among the three methods, the modified carbol fuchsin method gave the best result of deep staining and good contrast between nucleus and cytoplasm. 相似文献
11.
《中国海洋湖沼学报》2021,(2)
Phaeocystis globosa is an important harmful algal bloom causative species distributing widely in temperate and tropical coastal waters in the world.The morphological,physiological,and biochemical characte ristics are different amo ng geographic strains,which can not be distinguished with nuclear ribo somal DNA markers at present.Therefore,the genetic distance and phylogeographic relationships of nuclear 28 S rDNA D1-D2 and ITS regions,and three chloroplast intergenic spacers(petN-trnS1,trnM1-psbA,and rbcS-rpl27) were analyzed and compared among 13 strains of P.globosa isolated from the Pacific Ocean and Atlantic Ocean in this study.In addition,the nucleotide polymorphisms of 28 S rDNA D1-D2,ITS,and rbcS-rpl27 regions were evaluated in two P.globosa strains.The various levels of nucleotide polymorphism were in the nuclear 28 S rDNA D1-D2 region and ITS region,but no polymorphism was in the chloroplast rbcS-rpl27 intergenic spacer.A reasonable intraspecific phylogeographic relationship was presented by rbcS-rpl27 intergenic spacer,which had the strongest distinction to geographic strains compared to those of 28 S rDNA D1-D2 and ITS regions.In the phylogenetic tree of rbcS-rpl27 intergenic spacer,the two strains from the North Sea of the Atlantic Ocean were divided firstly from the species of P.globosa,and then formed an independent clade,while the other Atlantic strains and all of Pacific strains j oined up to build the other clade.It was implied that at least two genetically distant populations of P.globosa existed in the Atlantic coastal regions.This study provided a high-resolution chloroplast marker to analyze intraspecific phylogeographic populations of P.globosa,and preliminarily clarified the genetic relationships of the Pacific and Atlantic strains of P.globosa. 相似文献
12.
The phylogenetic relationship among Chinese Parapenaeopsis species was studied by comparing 16S rDNA and COI gene sequence. The results showed that Parapenaeopsis hardwickii (Miers, 1878) and P. cultrirostris Alcock, 1906 identified from Chinese samples were the same species. Parapenaeopsis cornuta (Kishinouye, 1900), P. incisa Liu and Wang, 1987, and P. sinica Liu and Wang, 1987 were different species. However, their systematic relationship were closer than those of other species, and they formed an advanced branch in the phylogenetic trees. Additionally, the systematic position of P. hardwickii (Miers, 1878), P. hungerfordi Alcock, 1905, and P. tenella (Bate, 1888) were not stable in the phylogenetic trees. More genetic markers such as 18S rDNA and 28S rDNA were supposed to be used to confirm the phylogenic relationship of Parapenaeopsis species. 相似文献
13.
The systematic classification of the Eucheumatoideae is difficult because of their variable morphology and interpretation of reproductive structures. Kappaphycus and Eucheuma specimens cultivated on the Hainan and Fujian coast of China were introduced from Vietnam, the Philippines and Indonesia. Combined with morphological characteristics, all Kappaphycus and Eucheuma cultivated strains were identified by internal transcribed spacer (ITS) sequences. The phylogenetic tree was constructed using neighbor-joining and maximum likelihood methods. The results indicate that different ITS sequence lengths occurred in the different genera and species. An obvious difference in morphology could be found in the protuberance shape between Kappaphycus and Eucheuma. The protuberance in Eucheuma was thorn-like and in Kappaphycus was wartlike or papillate. Their ITS sequence lengths differed significantly in nucleotide variation rates up to 58.55%-63.90%. All nucleotide variations occurred in the ITS1 and ITS2 regions except for five nucleotide transversions in the 5.8S rDNA region. In addition, the difference was at the branches among congeneric species. Kappaphycus sp. had branches with small buds, while K. alvarezii did not have such a feature. The nucleotide variation rates varied from 7.02% to 7.48% among species; within the same species of the clades it was <1.20%. Eucheumatoideae algae cultivated in China consisted of three clades, K. alvarezii, Kappaphycus sp., and E. denticulatum. The results indicate that ITS sequence analysis was an effective way for identification of interspecies and intraspecies phylogenetic relationships and might provide a clue for molecular identification of algal Eucheumatoideae. 相似文献
14.
Chlorophyta species are common in the southern and northern coastal areas of China. In recent years, frequent green tide incidents in Chinese coastal waters have raised concerns and attracted the attention of scientists. In this paper, we sequenced the 18S rDNA genes, the internal transcribed spacer (ITS) regions and the rbcL genes in seven organisms and obtained 536-566 bp long ITS sequences, 1 377-1 407 bp long rbcL sequences and 1 718-1 761 bp long partial 18S rDNA sequences. The GC base pair content was highest in the ITS regions and lowest in the rbcL genes. The sequencing results showed that the three Ulva prolifera (or U. pertusa) gene sequences from Qingdao and Nan’ao Island were identical. The ITS, 18S rDNA and rbcL genes in U. prolifera and U. pertusa from different sea areas in China were unchanged by geographic distance. U. flexuosa had the least evolutionary distance from U. californica in both the ITS regions (0.009) and the 18S rDNA (0.002). These data verified that Ulva and Enteromorpha are not separate genera. 相似文献
15.
黄喉拟水龟体表溃疡病原菌SG_(24)的分类鉴定 总被引：1，自引：0，他引：1
从患溃疡的黄喉拟水龟病灶中分离到一株病原菌SG24。对菌株SG24进行了常规生理生化测定和ATBExpression半自动细菌鉴定仪鉴定,并测定16S rRNA序列,分析其与相关细菌相应序列的同源性,构建了系统进化树。普通细菌学方法结果显示菌株SG24为黏质沙雷氏菌(Serratia marcescens)。以沙雷氏菌属的16S rRNA基因序列设计一对引物进行PCR扩增,获得了菌株SG24大小约950 bp的16S rRNA部分基因片段,测序结果显示菌株SG24与黏质沙雷氏菌同类,与已登录的黏质沙雷氏菌(S.marcescensDQ207558)的16S rRNA同源性大于99%。综合以上分类鉴定结果,确定菌株SG24属于沙雷氏菌属的黏质沙雷氏菌。药物敏感试验结果表明:菌株SG24对链霉素、庆大霉素、壮观霉素、强力霉素、卡那霉素、阿米卡星、诺氟沙星、氧氟沙星和复方新诺明敏感。 相似文献
16.
In this study, we integrated a DNA barcoding project with an ecological survey on intertidal polychaete communities and investigated
the utility of CO1 gene sequence as a DNA barcode for the classification of the intertidal polychaetes. Using 16S rDNA as
a complementary marker and combining morphological and ecological characterization, some of dominant and common polychaete
species from Chinese coasts were assessed for their taxonomic status. We obtained 22 haplotype gene sequences of 13 taxa,
including 10 CO1 sequences and 12 16S rDNA sequences. Based on intra- and inter-specific distances, we built phylogenetic
trees using the neighbor-joining method. Our study suggested that the mitochondrial CO1 gene was a valid DNA barcoding marker
for species identification in polychaetes, but other genes, such as 16S rDNA, could be used as a complementary genetic marker.
For more accurate species identification and effective testing of species hypothesis, DNA barcoding should be incorporated
with morphological, ecological, biogeographical, and phylogenetic information. The application of DNA barcoding and molecular
identification in the ecological survey on the intertidal polychaete communities demonstrated the feasibility of integrating
DNA taxonomy and ecology. 相似文献
17.
Shiqi Ji Rui Zhao Qi Yin Yuan Zhao Chenguang Liu Tian Xiao Xiaohua Zhang 《中国海洋大学学报(英文版)》2012,11(1):45-51
A gel microbead (GMD) cultivation method was employed to cultivate microorganisms from an amphioxus breeding zone in Qingdao, P. R. China. The culture results were compared with those by standard plating method. In the GMD-based method, the microcolony-forming GMDs were sorted by fluorescence-activated cell sorting (FACS). To further get pure cultures, a subsequent enrichment culture and a streaking purification procedure were conducted on marine R2A medium. Eighty bacterial strains isolated by the GMD-based method were randomly selected for sequencing. These isolates belonged to Alphaproteobacteria (33%), Gammaproteobacteria (44%), Bacteroidetes (11%), Actinobacteria (5%), Firmicutes (5%), Epsilonproteobacteria (1%), and Verrucomicrobia (1%), the last two groups being usually difficult to culture. The 16S rRNA gene sequences revealed a diverse community with 91.1%-100% of the bacterial rRNAs similarities. Thirteen strains were sharing 16S rRNA gene sequence which was less than 97% similar to any other rRNA genes currently deposited in TYP16S database. Seventy isolates derived from the standard plating method fell into 4 different taxonomic groups: Alphaproteobacteria (9%), Gammaproteobacteria (81%), Bacteroidetes (7%) and Firmicutes (3%) with a 16S rRNA gene sequence similarities between 95.8%-100%, in which only 3 strains were sharing 16S rRNA gene sequence of less than 97%. The results indicated that the GMD-based method with subenrichment culture yielded more taxonomic groups and more novel microbial strains, including members of previously rarely cultured groups, when compared with the standard plating method, and that this method markedly improved the bacterial cultivability. 相似文献
18.
The phylogenetic diversity of cuhurable psychrophilic bacteria associated with sea ice from the high latitude regions of Canadian Basin and Chukchi Sea, Arctic, was investigated. A total of 34 psychropilic strains were isolated using three methods of （ Ⅰ ） dilution plating （ at 4 ℃ ）, （ Ⅱ ） bath culturing （ at - 1 ℃ ） and dilution plating, and （ Ⅲ） cold shock （ -20 ℃ for 24 h）, bath culturing and dilution plating under aerobic conditions. Sea-ice samples were exposed to -20 ℃ for 24 h that might reduce the number of common microorganisms and encourage outgrowth of psyehrophilic strains. This process might be able to be introduced to isolation psychrophilic bacteria from other environmental samples in future study. 16S rDNA nearly full-length sequence analysis revealed that psychrophilic strains felled in two phylo- genetic divisions, γ-proteobacteria （in the genera ColweUia,Marinobaeter、Shewanella,Glaciecola,Marinomortas and Pseudoalteromortas ） and Cytophaga-Flexibacter-Baeteroides （ Flavobacterlum and Psyehroflexus）. Fifteen of bacterial isolates quite likely represented novel species （16S rDNA sequence similarity below 98% ）. One of strains （BSi20002） from Canadian Basin showed 100% sequence similarity to that of Marinobacter sp. ANT8277 isolated from the Antarctic Weddell sea ice, suggesting bacteria may have a bipolar distribution at the species level. 相似文献
19.
20.
Observation of female gamete （Carpogonia） germination of Porphyra yezoensis and P. oligospermatangia
Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades and conchocelis in the same culture of Porphyra. Study on samples of wild and cultivated Porphyra yezoensis and P. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown that the single cells of Porphyra yezoensis had typical features of female gamete （carpogonia） but archeospore. Therefore, the female gametes are responsible in developing leafy thalli. 相似文献