Genetic differentiation ofLiparus glabrirostris(Curculionidae: Molytinae) populations from the fragmented habitats of the Alps and Carpathian Mountains

AbstractPopulations ofLiparus glabrirostris(Curculionidae: Molytinae), a weevil inhabiting higher altitudes of Central Europe, were sampled from 24 localities in the Alps and Carpathian Mountains, and the geographical structuring of genetic variation was analyzed. Comparison of the concatenated mitochondrial cytochrome oxidase subunit I and subunit II sequences revealed consistent genetic divergence between the populations ofL. glabrirostrisfrom different mountain ranges. In phylogenetic analysis using maximum parsimony and median-joining networks, concatenated mitochondrial haplotypes from the Alps and Carpathians clustered as separate lineages, with high bootstrap support. Substantial genetic distances determined between the separated groups ranged from 2.6 to 3.0%, with divergence estimated to have initiated approximately 0.85–0.98 million years ago. The nuclear elongation factor 1α gene was additionally amplified and haplotype analysis showed very low evolutionary divergence (0.2%), with separate clustering as well. The observed divergence suggests that the populations have been isolated for a long time, as a consequence of environmental changes resulting in varying fragmentation of habitats in the Alps and Carpathians, interrupting genetic exchange events and altering the genetic structure ofL. glabrirostrispopulations. On the other hand, comparison of morphological characteristics showed no differences to confirm genetically well differentiated groups of populations. A polymerase chain reaction and restriction fragment length polymorphism-based method was therefore developed to discriminate between the Alpine and Carpathian lineages.

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Macrophomina vaccinii Causes a Basal Stem and Root Rot of Patchouli (Pogostemon cablin) in China

Plant Disease ◽

10.1094/pdis-06-21-1300-pdn ◽

2021 ◽

Author(s):

Ying Xin Fang ◽

Jin Ling Li ◽

Xiao Fei Li ◽

Min Zhong Chen ◽

Jia Yi Lin ◽

...

Keyword(s):

Root Rot ◽

Elongation Factor ◽

Morphological Characteristics ◽

Perennial Herb ◽

Bootstrap Support ◽

Molecular Characteristics ◽

Plastic Bags ◽

Pogostemon Cablin ◽

Pure Cultures ◽

Rot Disease

Patchouli (Pogostemon cablin Benth.) is a perennial herb native to South and South East Asia, which widely used as a traditional herbal medicine against indigestion, diarrhea, cold, fever, vomiting and headache in China (Swamy and Sinniah, 2015). In September 2020, a new basal stem and root rot disease of patchouli was observed in three cultivated fields of Zhanjiang City, Guangdong Province. Symptoms included sudden discoloration, chlorosis and wilting of the leaves and severe rot associated with external and internal browning at the basal part of stems and roots that results in the death of approximately 2 to 5% of plants in each field. To determine the causal agent, symptomatic roots with typical lesions were cut into small pieces, then surface sterilized in 2.5% NaClO for 1 min, rinsed three times in distilled water, and then inoculated on potato dextrose agar (PDA) medium. A fungus with same morphological characteristics was consistently isolated from disease tissue. The mycelia initially white to cream, later turning pale brown to black with age on PDA. To induce the sporulation, the isolated fungi were transferred to synthetic nutrient-poor agar (SNA) with autoclaved pine needles and ten pure cultures were obtained by single spores. Masses of black, hard and oblong microsclerotia (av. 171.2×136.5 µm, n=50) were observed on SNA. Conidia hyaline, ellipsoid to obovoid, smooth, enclosed in a mucous sheath, 15.9~32.5×7.7~11.9 µm (av. 23.9 × 9.6 µm, n=100). The internal transcribed spacer (ITS) regions as well as the partial translation elongation factor (EF-1α) and β-tubulin (TUB) genes of two representative isolates GHX-1 and CHX-2 were sequenced, using primer pairs ITS1/ITS4 (White et al. 1990), EF-688F/EF-986R (Carbone and Kohn 1999), and Bt2a/Bt2b (Glass and Donaldson 1995), respectively. The obtained sequences were submitted to GenBank under the following accession numbers: ITS, MZ375360 and MZ375361; EF-1α, MZ393804 and MZ393805; and TUB, MZ393806 and MZ393807. BLASTn searches revealed that 100% identity with the existing sequences of ex-type culture CGMCC3.19503 of Macrophomina vaccinii (ITS, MK687450; EF-1α, MK687426; and TUB, MK687434), respectively. Phylogenetic analysis using Neighbour-Joining method in Mega7.0 with concatenated sequences of ITS, EF-1α and TUB showed that the isolates clustered in the clade of M. vaccinii with high bootstrap support values. Based on both of the morphological and molecular results, the isolates were identified as M. vaccinii (Zhao et al., 2019). To confirm the pathogenicity of the two isolates, 5-mm-diameter mycelial agar plus from the margins of 5-day-old PDA cultures were placed on the wounded basal stem of 2-month-old patchouli seedlings in each pot. Five separate pots were used for each isolate and plants inoculated with sterile agar plus were served as controls. All plants were covered with plastic bags to maintain 90% relative humidity and kept at 26°C with a photoperiod of 12 h in a greenhouse conditions. The patchouli plants developed similar necrotic symptoms on basal stem and root to those observed in the field after 3 weeks after inoculation, whereas the control plants were asymptomatic. M. vaccinii was reisolated from inoculated plants and identify by morphological and molecular characteristics, fulfill the Koch’s postulates and identify. Recently, stem blight on blueberry caused by M. vaccinii was reported in China (Zhao et al. 2019). To our knowledge, this is the first report of M. vaccinii causing basal stem and root rot on patchouli in China and worldwide.

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A new species and three subspecies of the desert shrew (Notiosorex) from the Baja California peninsula and California

Journal of Mammalogy ◽

10.1093/jmammal/gyaa045 ◽

2020 ◽

Vol 101 (3) ◽

pp. 872-886

Author(s):

Issac Camargo ◽

Sergio Ticul Álvarez-Castañeda

Keyword(s):

Cytochrome C ◽

Cytochrome C Oxidase ◽

Baja California ◽

Colorado River ◽

Phylogenetic Analyses ◽

Morphological Characteristics ◽

Genetic Distances ◽

Baja California Peninsula ◽

Bootstrap Support ◽

Oxidase Subunit

Abstract Desert shrews of the genus Notiosorex comprise four species with morphological characteristics that are difficult to distinguish among the species. Indeed, N. cockrumi was described using only genetic markers. Based on molecular divergence documented in N. crawfordi, we hypothesize that a fifth species is present in the Baja California peninsula. Genetic variation at the species level was analyzed using individuals from locations west of the Colorado River in the Baja California peninsula, Mexico, and California, United States. Molecular markers of mitochondrial origin (cytochrome b, 1,140 bp; cytochrome c oxidase subunit I, 542 bp; and cytochrome c oxidase subunit III, 672 bp), as well as the nuclear intron 7 of the beta fibrinogen gene (385 bp) were used to construct a phylogeny for species of the genus Notiosorex. Genetic distances of 12.46–15.58% between west and east of the Colorado River were obtained using p-distance models. Our phylogenetic analyses showed almost identical topologies, placing populations from west of the Colorado River in three monophyletic clades with high bootstrap support values. Results of molecular phylogenetic identity among shrews of the genus Notiosorex support the existence of an undescribed, polytypic species of Notiosorex west of the Colorado River.

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First Report of Leaf Spot Caused by Nigrospora aurantiaca in Tobacco in China

Plant Disease ◽

10.1094/pdis-06-20-1201-pdn ◽

2020 ◽

Author(s):

Yu Huang ◽

Zhong LI ◽

Han-cheng Wang ◽

Qianli Chen ◽

Wen hong Li

Keyword(s):

Leaf Spot ◽

Management Practices ◽

Large Subunit ◽

Elongation Factor ◽

Morphological Characteristics ◽

Leaf Tissue ◽

Guizhou Province ◽

Bootstrap Support ◽

First Report ◽

Pcr Products

Tobacco (Nicotiana tabacum L.) is one of the most important cash crops in China. In June 2019, tobacco (cv. Yunyan 87) samples with gray spots surrounded by yellowish ring were collected in Zhengan (107.43° N, 28.55° E), Guizhou province, China. Pieces of leaf tissue (3 mm × 3 mm) that were cut at the junction of diseased and healthy portion were surface sterilized and plated on potato dextrose agar (PDA). After incubation at 25°C in the dark for 7 days, an isolate (T22) was chosen and used for pathogen identification. The colonies had aerial hyphae, initially white and then turned grey, and produced a soluble red pigmen on PDA. The colonies were floccose aerial mycelia, dark grey, with pale brown hyphae, and produced conidia on oatmeal agar. Conidia were ovoid or ampulliform, black, smooth. Based on morphological characteristics, isolate T22 was identified as Nigrospora aurantiaca (Wang et al. 2017). For molecular identification, the large subunit (LSU) and internal transcribed spacer (ITS) of ribosomal RNA, β-tubulin (TUB) and translation elongation factor 1-alpha (TEF1) genes of T22 were amplified by PCR with the primer sets LROR/LR5, ITS1/ITS4, Bt2a/Bt2b and EF1-728F/EF2 (Suwannarach et al.2019), then PCR products were sequenced. Their GenBank accession numbers were MT341787, MT328649, MT348395 and MT348394, respectively. Phylogenetic tree of combined LSU, ITS, TUB, and TEF sequences showed that isolate T22 was assigned to N. aurantiaca strain (CGMCC 3.18130 and LC 7034) with 100% bootstrap support. Based on morphological characteristics and multi-gene molecular analysis, isolate T22 was identified as N. aurantiaca. To fulfill Koch’s postulates, PDA plugs grown with N. aurantiaca were placed on the leaves of four tobacco plants (cv. Yunyan 87) at the 10-leaf stage. Leaves inoculated with PDA only plugs served as the controls. Treated plants were maintained in a greenhouse with temperatures ranging from 18 to 28 °C. Five days after inoculation, typical symptoms were observed on inoculated leaves but not on the controls. N. aurantiaca was re-isolated from the diseased leaves but not from the controls. To our best of knowledge, this is the first report of N. aurantiaca causing leaf spot on tobacco in China. N. aurantiaca has been reported to cause leaf spot on Castanea mollissima in China (Luo et al. 2020). Due to potential serious damage caused by the disease in this region, proper disease management practices should be developed and implemented.

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Identification of Lasiodiplodia pseudotheobromae Causing Fruit Rot of Citrus in China

Plants ◽

10.3390/plants10020202 ◽

2021 ◽

Vol 10 (2) ◽

pp. 202

Author(s):

Jianghua Chen ◽

Zihang Zhu ◽

Yanping Fu ◽

Jiasen Cheng ◽

Jiatao Xie ◽

...

Keyword(s):

Phylogenetic Analyses ◽

Elongation Factor ◽

Morphological Characteristics ◽

Citrus Fruit ◽

Economic Loss ◽

Fruit Rot ◽

Post Inoculation ◽

Citrus Reticulata ◽

Postharvest Diseases ◽

Citrus Reticulata Blanco

Considering the huge economic loss caused by postharvest diseases, the identification and prevention of citrus postharvest diseases is vital to the citrus industry. In 2018, 16 decayed citrus fruit from four citrus varieties—Satsuma mandarin (Citrus unshiu), Ponkan (Citrus reticulata Blanco cv. Ponkan), Nanfeng mandarin (Citrus reticulata cv. nanfengmiju), and Sugar orange (Citrus reticulata Blanco)—showing soft rot and sogginess on their surfaces and covered with white mycelia were collected from storage rooms in seven provinces. The pathogens were isolated and the pathogenicity of the isolates was tested. The fungal strains were identified as Lasiodiplodia pseudotheobromae based on their morphological characteristics and phylogenetic analyses using the internal transcribed spacer regions (ITS), translation elongation factor 1-α gene (TEF), and beta-tubulin (TUB) gene sequences. The strains could infect wounded citrus fruit and cause decay within two days post inoculation, but could not infect unwounded fruit. To our knowledge, this is the first report of citrus fruit decay caused by L. pseudotheobromae in China.

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Radiomorphology of the Habib Sealer-Induced Resection Plane during Long-Time Followup:A Longitudinal Single Center Experience after 64 Radiofrequency-AssistedLiver Resections

HPB Surgery ◽

10.1155/2010/403097 ◽

2010 ◽

Vol 2010 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Robert Kleinert ◽

Roger Wahba ◽

Christoph Bangard ◽

Klaus Prenzel ◽

Arnulf H. Hölscher ◽

...

Keyword(s):

Liver Resection ◽

Morphological Characteristics ◽

Postoperative Mortality ◽

Coagulation Necrosis ◽

Time Interval ◽

Safe Alternative ◽

Time Points ◽

Single Center Experience ◽

Long Time

Background. Radiofrequency (RF-) assisted liver resection devices like the Habib sealer induce a necrotic resection plane from which a small margin of necrotic liver tissue remains in situ. The aim of the present paper was to report our long-time experience with the new resection method and the morphological characteristics of the remaining necrotic resection plane. Methods. 64 RF-assisted liver resections were performed using the Habib sealer. Followup was assessed at defined time points. Results. The postoperative mortality was 3,6% and morbidity was 18%. The followup revealed that the necrotic zone was detectable in all analyzed CT and MRI images as a hypodense structure without any contrast enhancement at all time points, irrespectively of the time interval between resection and examination. Conclusion. Liver resection utilizing radiofrequency-induced resection plane coagulation is a safe alternative to the established resection techniques. The residual zone of coagulation necrosis remains basically unchanged during a followup of three years. This has to be kept in mind when evaluating the follow up imaging of these patients.

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Rhizobium tropici Genes Involved in Free-Living Salt Tolerance are Required for the Establishment of Efficient Nitrogen-Fixing Symbiosis with Phaseolus vulgaris

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2002.15.3.225 ◽

2002 ◽

Vol 15 (3) ◽

pp. 225-232 ◽

Cited By ~ 110

Author(s):

Joaquina Nogales ◽

Rosario Campos ◽

Hanaa BenAbdelkhalek ◽

José Olivares ◽

Carmen Lluch ◽

...

Keyword(s):

Salt Tolerance ◽

Phaseolus Vulgaris ◽

Environmental Changes ◽

Nitrogenase Activity ◽

Regulation Of Gene Expression ◽

Elongation Factor ◽

Regulatory System ◽

Trna Synthetase ◽

Nitrogen Fixing ◽

Rhizobium Tropici

Characterization of nine transposon-induced mutants of Rhizobium tropici with decreased salt tolerance (DST) allowed the identification of eight gene loci required for adaptation to high external NaCl. Most of the genes also were involved in adaptation to hyperosmotic media and were required to overcome the toxicity of LiCl. According to their possible functions, genes identified could be classified into three groups. The first group included two genes involved in regulation of gene expression, such as ntrY, the sensor element of the bacterial ntrY/ntrX two-component regulatory system involved in regulation of nitrogen metabolism, and greA, which encodes a transcription elongation factor. The second group included genes related to synthesis, assembly, or maturation of proteins, such as alaS coding for alanine-tRNA synthetase, dnaJ, which encodes a molecular chaperone, and a nifS homolog probably encoding a cysteine desulfurase involved in the maturation of Fe-S proteins. Genes related with cellular build-up and maintenance were in the third group, such as a noeJ-homolog, encoding a mannose-1-phosphate guanylyltransferase likely involved in lipopolysaccharide biosynthesis, and kup, specifying an inner-membrane protein involved in potassium uptake. Another gene was identified that had no homology to known genes but that could be conserved in other rhizobia. When inoculated on Phaseolus vulgaris growing under nonsaline conditions, all DST mutants displayed severe symbiotic defects: ntrY and noeJ mutants were impaired in nodulation, and the remaining mutants formed symbiosis with very reduced nitrogenase activity. The results suggest that bacterial ability to adapt to hyper-osmotic and salt stress is important for the bacteroid nitrogen-fixing function inside the legume nodule and provide genetic evidence supporting the suggestion that rhizobia face severe environmental changes after their release into plant cells.

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CULTURAL AND CHRONOLOGICAL ATTRIBUTION OF MIDDLE NEOLITHIC MATERIALS FROM THE SETTLEMENTS USHAKOVO 3 AND PRIBREZHNOYE

Краткие сообщения Института археологии (КСИА) ◽

10.25681/iaras.0130-2620.258.46-64 ◽

2020 ◽

Author(s):

Э.Б. Зальцман

Keyword(s):

Coastal Area ◽

Morphological Characteristics ◽

Wall Structure ◽

Vistula Lagoon ◽

New Materials ◽

Double Row ◽

Long Time ◽

Funnel Beaker Culture ◽

The Baltic ◽

The Vistula Lagoon

В работе характеризуются новые материалы, полученные в ходе исследований неолитических (по прибалтийской периодизации) поселений побережья Вислинского залива. Данные древности, по всем признакам, относятся к культуре воронковидных кубков, памятники которой ранее в регионе были неизвестны. Все материалы КВК выявлены на поселениях, основные культурные комплексы с которых относятся к приморской культуре шнуровой керамики (рис. 1). Незначительные по размерам стоянки КВК существовали здесь до прихода населения приморской культуры. В Ушаково 3 керамика КВК найдена в культурном слое в восточной части раскопа, где она залегала в основном отдельно от керамики приморской культуры (рис. 2–4). В Прибрежном кроме керамических материалов зафиксированы следы 2 построек с двухрядной столбовой конструкцией стен (рис. 5). Постройки наземного типа, удлиненной формы, шириной не более 3,2 м. Технологические и морфологические характеристики фрагментов керамики, обнаруженной в пределах построек, не оставляют сомнений в том, что эти комплексы принадлежат КВК (рис. 6: 1, 13). Кроме того, здесь же выявлены две амфоры с типичными чертами баденизации в КВК (рис. 6: 14, 15). Керамика КВК встречалась также и в культурном слое поселения (рис. 7: 1, 3, 4, 6, 7, 10, 12). Все материалы КВК с поселений Ушаково 3 и Прибрежное датируются в диапазоне 3500–3100 гг. CalBC (Приложение 1). Наиболее вероятно, что небольшие по численности группы населения КВК проникли в прибрежную зону около середины IV тыс. до н. э., когда на этой территории уже продолжительное время существовали местные сообщества цедмарской неолитической культуры. The paper characterizes new materials obtained during the excavations of Neolithic sites (according to the Baltic periodization) in the Vistula Lagoon coast. These antiquities are attributed to the Funnel Beaker culture the sites of which have not been discovered in this region before. All FBC materials were identified at settlements where the main cultural assemblages are attributed to the Primorskaya Corded Ware Culture (Fig. 1). Small FBC sites had existed in this area before the arrival of the Primorskaya culture population. Ushakovo 3 revealed FBC ceramics in the occupation layer located in the eastern part of the excavation trench where, in most cases, these artifacts were lying separately from the Primorskaya culture ceramics (Fig. 2–4). Traces of two constructions with a double-row pillar wall structure (Fig. 5) were recorded at Pribrezhnoye. Technological and morphological characteristics of the ceramics discovered in the constructions leave no doubt that these assemblages belong to the FBC (Fig. 6: 1, 13). Two amphorae with typical features of «badenization» in the FBC were discovered at this site as well (Fig. 6: 14, 15). The FBC ceramics also occurred in the occupation layer of the site (Fig. 7: 1, 3, 4, 6, 7, 10, 12). All FBC materials from Ushakovo 3 and Pribrezhnoye fall within 3500–3100 CalBC (Appendix 1). Most likely, around mid 4th millennium BC small FBC population groups reached the coastal area which had been already inhabited by local Zedmar Neolithic communities for a long time.

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Ser/Thr phospho-regulation by PknB and Stp mediates bacterial quiescence and antibiotic persistence in Staphylococcus aureus

10.1101/2021.05.06.442895 ◽

2021 ◽

Author(s):

Markus Huemer ◽

Srikanth Mairpady Shambat ◽

Sandro Pereira ◽

Lies Van Gestel ◽

Judith Bergada-Pijuan ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Ribosomal Proteins ◽

Environmental Changes ◽

Acid Stress ◽

Elongation Factor ◽

Growth Delay ◽

Lag Phase ◽

Cellular Processes ◽

Translational Activity

Staphylococcus aureus colonizes 30 to 50% of healthy adults and can cause a variety of diseases, ranging from superficial to life-threatening invasive infections such as bacteraemia and endocarditis. Often, these infections are chronic and difficult-to-treat despite adequate antibiotic therapy. Most antibiotics act on metabolically active bacteria in order to eradicate them. Thus, bacteria with minimized energy consumption resulting in metabolic quiescence, have increased tolerance to antibiotics. The most energy intensive process in cells - protein synthesis - is attenuated in bacteria entering into quiescence. Eukaryote-like serine/threonine kinases (STKs) and phosphatases (STPs) can fine-tune essential cellular processes, thereby enabling bacteria to quickly respond to environmental changes and to modulate quiescence. Here, we show that deletion of the only annotated functional STP, named Stp, in S. aureus leads to increased bacterial lag-phase and phenotypic heterogeneity under different stress challenges, including acidic pH, intracellular milieu and in vivo abscess environment. This growth delay was associated with reduced intracellular ATP levels and increased antibiotic persistence. Using phosphopeptide enrichment and mass spectrometry-based proteomics, we identified possible targets of Ser/Thr phosphorylation that regulate cellular processes and bacterial growth, such as ribosomal proteins including the essential translation elongation factor EF-G. Finally, we show that acid stress leads to a reduced translational activity in the stp deletion mutant indicating metabolic quiescence correlating with increased antibiotic persistence.

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Build a Better Bootstrap and the RAWR Shall Beat a Random Path to Your Door: Phylogenetic Support Estimation Revisited

10.1101/2020.02.02.931063 ◽

2020 ◽

Author(s):

Wei Wang ◽

Kevin J. Liu

Keyword(s):

State Of The Art ◽

Bootstrap Method ◽

Parametric Method ◽

Open Data ◽

Bootstrap Support ◽

Future Research ◽

Evolutionary Divergence ◽

Type I ◽

Support Estimation ◽

Non Parametric

AbstractMotivationThe standard bootstrap method is used throughout science and engineering to perform general-purpose non-parametric resampling and re-estimation. Among the most widely cited and widely used such applications is the phylogenetic bootstrap method, which Felsenstein proposed in 1985 as a means to place statistical confidence intervals on an estimated phylogeny (or estimate “phylogenetic support”). A key simplifying assumption of the bootstrap method is that input data are independent and identically distributed (i.i.d.). However, the i.i.d. assumption is an over-simplification for biomolecular sequence analysis, as Felsenstein noted. Special-purpose fully parametric or semi-parametric methods for phylogenetic support estimation have since been introduced, some of which are intended to address this concern.ResultsIn this study, we introduce a new sequence-aware non-parametric resampling technique, which we refer to as RAWR (“RAndom Walk Resampling”). RAWR consists of random walks that synthesize and extend the standard bootstrap method and the “mirrored inputs” idea of Landan and Graur. We apply RAWR to the task of phylogenetic support estimation. RAWR’s performance is compared to the state of the art using synthetic and empirical data that span a range of dataset sizes and evolutionary divergence. We show that RAWR support estimates offer comparable or typically superior type I and type II error compared to phylogenetic bootstrap support as well as GUIDANCE2, a state-of-the-art purpose-built fully parametric method. Additional simulation study experiments help to clarify practical considerations regarding RAWR support estimation. We conclude with thoughts on future research directions and the untapped potential for sequence-aware non-parametric resampling and re-estimation.AvailabilityData and software are publicly available under open-source software and open data licenses at: https://gitlab.msu.edu/liulab/[email protected]

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DNA barcodes and morphology of P. krempfi, P. mekongensis, and P. elongatus

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/14/1/9289 ◽

2016 ◽

Vol 14 (1) ◽

pp. 29-37 ◽

Cited By ~ 1

Author(s):

Dương Thúy Yên ◽

Nguyễn Kiệt ◽

Bùi Sơn Nên ◽

Nguyễn Văn Thường ◽

Nguyễn Bạch Loan ◽

...

Keyword(s):

Dna Barcode ◽

Morphological Characteristics ◽

Mekong Delta ◽

Genetic Distances ◽

Dna Barcodes ◽

Gill Rakers ◽

Coi Sequences ◽

Relationship Of ◽

Metric Traits ◽

I Gene

Three Pangasius species including P. krempfi, P. elongatus and P. mekongensis, are economically important. They can be mis-identified due to similar external appreance at small sizes. This study aimed to distinguish these species based on their differences in DNA barcode, COI (cytochrome c oxidase subunit I) gene, and morphological characteristics. Fish with various sizes (>90 samples/species) were sampled at the lower Mekong delta region. Kimura-2 parameter genetic distances based on COI sequences of three species (15 samples, in which, 4 unique sequences were assigned Genbank accession numbers from KT289877 to KT289880) are relatively high, ranging 9.33 – 12.10 %. Morphological measurements show that coutanble traits including numbers of fin rays and the first gill rakers vary in similar ranges but ratios of metric traits are significantly different among three species (P<0.01). Principle component analysis using metric traits sets three species apart. P. elongatus is characterized by elongated body, long caudal preduncle, large eyes, and retangle palatine tooth plates. P. krempfi differs from P. mekongesis in characteristics on their head. The number of sections, shape and length of barbel are different among three species. Phylogenetic relationship of three species based on morphology and COI sequences indicate that P. krempfi is closer to P. mekongenis rather than P. elongatus, and that the distance between P. mekongenis and P. elongatus is the largest.

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