264 research outputs found
Review of Aquaculture Genetic Researches in Thailand
Aquaculture business has been well established in Thailand for more than 40 years. The most recent data indicated a total production of 260 380 tons. Sixty-five percent of the total production came from coastal aquaculture, mainly tiger prawn (Penaeus monodon) culture. Other important species for coastal aquaculture are banana prawn (P. merguensis), cockle (Anadara granosa), green mussel (Perna viridis), oyster (Crassostrea belcheri, Saccostrea commercialis), sea bass (Lates calcarifer) and grouper (Epinephelus tauvina). Freshwater aquaculture, although produced only 35% of the annual production, provides major protein source for people in rural areas. Important freshwater species are Nile tilapia (Oreochromis niloticus), tawes (Puntius gonionotus), sepat Siam (Trichogasterpectoralis), walking catfish (Glorias spp.), stripped catfish (Pangasius sutchi) and giant freshwater prawn (Macrobrachium rosenbergii). Optimum aquacultural practises, namely stocking density, nutrition requirement and water quality have been obtained in most cultured species. But genetic approach has not been considered, thus resulting in deterioration in economic traits which might be due to excessive inbreeding (reviewed by Uraiwan 1989) and/or negative selection (Wongsangchan 1985). The history of researches on genetics in aquaculture in Thailand started in 1982 when the aquaculture genetic programme in form of a network has been established at the National Inland Fisheries Institute, Department of Fisheries. This programme was supported by the International Development Research Centre (IDRC, Canada) in cooperation with Dalhousie University, Canada (Uraiwan 1989). In the same year a genetic improvement programme aiming at improving economic characters of some economic fish species has been conducted at the Department of Aquaculture, Kasetsart University. Paralelly a course in Fish Genetics has been offered. Since then different approaches of genetics have been applied with final objectives on improving aquaculture production of the country. Researches being conducted are reviewed according to the following fish species
Population genetics of the spotted seahorse (Hippocampus kuda) in Thai waters : implications for conservation
A population genetics approach was used to investigate the genetic diversity of the spotted seahorse (Hippocampus kuda) in Thai waters; specifically, the degree of genetic differentiation and species evolution was inferred from sequence analysis of 353 bp of the mitochondrial (mt)DNA control region. The data were then used to identify discrete populations in Thai waters for effective conservation and management. Spotted seahorses were collected from 4 regions on the east and west coasts of the Gulf of Thailand and a geographically separated region in the Andaman Sea. Of the 101 mtDNA sequences analyzed, 7 haplotypes were identified, 5 of which were shared among individuals from the east and west coasts of the Gulf of Thailand. The remaining haplotypes were restricted to individuals from the Andaman Sea. Nucleotide and haplotype diversities were similar within the Gulf of Thailand samples, whereas diversity was lower in the Andaman Sea sample. Genetic differentiation appeared between pairs of samples from the Gulf of Thailand and Andaman Sea (FST, p < 0.0001). A large genetic variance appeared among the 2 population groups (94.46%, ΦCT = 0.94464, p < 0.01). A Neighbor-joining tree indicated that individuals from the Gulf of Thailand and Andaman Sea formed 2 phylogenetically distinct groups, which were segregated into different population-based clades. While results reported here indicate that populations from the Gulf of Thailand and Andaman Sea should be treated as separate conservation units, a larger sample size from the Andaman Sea is required to confirm this genetic partitioning and low level of diversity observed in the present study.<br /
Manual on application of molecular tools in aquaculture and inland fisheries management. Part 2. Laboratory protocols and data analysis
The aim of this manual is to provide a comprehensive practical tool for the generation and analysis of genetic data for subsequent application in aquatic resources management in relation to genetic stock identification in inland fisheries and aquaculture.
The material only covers general background on genetics in relation to aquaculture and fisheries resource management, the techniques and relevant methods of data analysis that are commonly used to address questions relating to genetic resource characterisation and population genetic analyses. No attempt is made to include applications of genetic improvement techniques e.g. selective breeding or producing genetically modified organisms (GMOs). The manual includes two ‘stand-alone’ parts, of which this is the second volume:
Part 1 – Conceptual basis of population genetic approaches: will provide a basic foundation on genetics in general, and concepts of population genetics. Issues on the choices of molecular markers and project design are also discussed.
Part 2 – Laboratory protocols, data management and analysis: will provide step-by-step protocols of the most commonly used molecular genetic techniques utilised in population genetics and systematic studies. In addition, a brief discussion and explanation of how these data are managed and analysed is also included.
This manual is expected to enable NACA member country personnel to be trained to undertake molecular genetic studies in their own institutions, and as such is aimed at middle and higher level technical grades. The manual can also provide useful teaching material for specialised advanced level university courses in the region and postgraduate students. The manual has gone through two development/improvement stages. The initial material was tested at a regional workshop and at the second stage feedback from participants was used to improve the contents
Variasi DNA Mitokhondria dari Ikan kakap Putih Budidaya dan Dari Tangkapan Liar Di Thailand
Kakap Putih (Lates calcarifer Bloch) adalah salah satu ikan ekonomis penting yang benihnya dapat diproduksi Thailand. Data genetik merupakan salah satu aspek penting dalam mengatur pemijahan induk untuk pemuliaan, namun hingga saat ini informasi terkait keragaman genetiknya masih minim. Penelitian ini bertujuan mengkaji keragaman dan perbedaan genetik kakap putih pada tiga populasi hatchery dan dua populasi alam di Thailand dengan menggunakan metode gabungan antara Restriction Fragment Length Polymorphisms dan Polymerase Chain Reaction (PCR-RFLP) pada D-loop control region di DNA mitokondria. Ditemukan tujuh potongan endonuklease dari 268 sampel yang diamati. Populasi alami Chantaburi (CH) memiliki keragaman haplotipe dan nukleotida tertinggi (h = 0.6626, π = 0.0554) dibandingkan populasi lainnya: tiga populasi hatcheri yaitu Rayong (RA), Chonburi (CB) dan Nakhon Si Thammarat (NK) ) (h berkisar antara 0.2709 – 0.3227; π berkisar antara 0.0195 – 0.386) dan populasi alam Nakhon Si Thammarat (PN) (h = 0.172, π = 0.0091). Mismatch distribution analysis mengungkap kejadian bottleneck pada beberapa generasi sebelumnya di populasi alam PN dan seluruh populasi hatcheri. Analysis of Molecular Variance (AMOVA) menunjukkan 88.95% keragaman disebabkan perbedaan dalam populasi dan 11.05 % disebabkan perbedaan antar populasi. Perbedaan genetik yang signifikan terdapat pada perbedaan antar populasi alam (ΦST = 0.239, P<0.001), namun perbedaan antar populasi hatchery tidak signifikan, menunjukkan terjadi pencampuran genetik sekerabat antar satu dengan hatcheri lainnya. Hal ini karena minimnya masukkan indukan baru dari alam. Kedua hal tersebut dapat menurunkan keragaman dan perbedaan genetik pada setiap populasi hatchery dan antar populasi hatchery. Data awal penelitian ini dapat digunakan unt
The impact of corporate venturing on firms’ innovation and organisational learning:A study of large manufacturing firms in Thailand
Research on corporate entrepreneurship suggests that corporate venturing is the most influential determinant to facilitate entrepreneurial performance among established corporations. Particularly, corporate venturing’s strategic use has been viewed as a crucial tool in achieving sustained competitive advantage through the acquisition of innovation and organisational learning. However, understanding the influences of a firm’s external and internal business environments on strategic corporate venturing (SCV) is still limited. This study addresses this issue by investigating the effects of three environmental and organisational mechanisms (i.e., market turbulence, cross-functional interfaces, and shared-organisational vision) on the relationship between SCV and firms’ product innovation and knowledge acquisition. The research incorporated resource-based and knowledge-based views of firms to explain the adoption of innovation and organisational learning for sustained competitive advantage. This study's sample is composed of two primary groups of key respondents: general managers and CEOs, from 190 large manufacturing firms in Thailand. The findings indicate that the use of SCV positively affects product innovation. Additionally, the results reveal that shared-organisational vision has a positive moderating effect on this observed relationship. Further, the study indicates that cross-functional interfaces have a negative moderating effect on the use of SCV in acquiring new knowledge. Overall, this study's findings enrich the limited understanding of the potential impacts of market turbulence, cross-functional interfaces, and shared-organisational vision to enhance product innovation and knowledge acquisition when the firm conducts SCV. It also introduces a four-item scale to statistically measure SCV and provides evidence to the policy makers that they can use SCV to enhance their entrepreneurial performance
The influence of SP-C variants and the SP-B model peptide KL4 on the surface properties of lipid monolayers at the air/water interface
Die Auf- und Entfaltung des Lungensurfactant während des Atemzykluses wird durch die Proteine SP-B und SP-C unterstützt. SP-C stabilisiert die Multischichten des komprimierten Oberflächenfilms, indem seine Alpha-Helix die ausgestülpte Doppelschicht durchdringt, während seine Palmitoylketten in der Monoschicht ankern. Mittels Filmwaage, Fluoreszenzmikroskopie und Rasterkraftmikroskopie konnte an einem DPPC/DPPG 4:1 Modellsystem mit verschiedenen SP-C Fragmenten dieser Mechanismus detailiert beleuchtet werden. Um 10 Aminosäuren verkürztes SP-C kann bei hohen Drücken keine Multischichten mehr stabilisieren. Depalmitoyliertes SP-C verflüssigt die Monoschicht und bildet filamentartige Ausstülpungen anstelle von Multischichten. Das Terapeutikum KL4 wurde mit oben genannten Methoden auf seine biophysikalische Vergleichbarkeit mit SP-B überprüft. Beide Substanzen verflüssigen zwar den Oberflächenfilm, jedoch können bei KL4 keine Membranausstülpungen beobachtet werden
Effects of Gibberellic Acid on Fruit Growth and Fruit Development of Mangosteen (Garcinia mangostana Linn.)
Na Nakorn, S. and Intraratsamee, A. (2015). Effects of gibberellic acid on fruit growth and fruit development of mangosteen (Garcinia mangostana Linn.). International Journal of Agricultural Technology 11(2):335-340. Abstract The different concentrations of gibberelic acid (GA 3 ) applied by spraying on the 15-year-old magosteen trees during the full bloom and fruit setting stage. The study was conducted at the Chumphon Research and Training Centre, Faculty of Agriculture, Rajamangala University of Technology Srivijaya, Chumphon province from Mach, 2009 to Mach, 2010. The experiment was used the Completely Randomized Design (CRD) with 5 replications. The different GA 3 concentrations were evaluated: 0 25 50 75 and 100 ppm. The results of the study showed no significant differences among treatment means between GA 3 applied in different concentrations with control in parameter of fruit size (width and length) and fruit weight during fruit growth and fruit development at 15-45 days. After 60-120 days, the result showed differences among treatment means between GA 3 applied in different concentrations with control in parameter of fruit size (width and length) and fruit weight. Also, the different concentrations of GA 3 was affect of peel weight and aril weight. The total soluble solid (TSS) was recorded data that there is no significance found on the sweetness of fruit obtained from both treated and untreated trees
Variation and long term regenerative capacity of two important tropical forage legumes: Cavalcade (Centrosema pascuorum cv. Cavalcade) and Stylo 184 (Stylosanthes guianensis CIAT184) in vitro
Shoots of Cavalcade (Centrosema pascuorum cv. Cavalcade) and Stylo 184 (Stylosanthes guianensis CIAT 184) from in vitro germinated seeds were cultured on Murashige and Skoog (MS) medium supplemented with 0 to 7 mg L-1 N 6-benzyladenine (BA) in combination with 0 to 0.5 mg L-1 napthalene acetic acid (NAA) for shoot induction and MS supplemented with 0 to 0.5 mg L-1 indolebutyric acid (IBA) for root induction. For Cavalcade, the medium containing 1 mg L-1 BA produced the best shoot multiplication with an excess of six shoots produced from a single shoot (over four weeks) with a mean height 2.0 ± 0.01 cm. Adventitious shoot regeneration was obtained directly from stem axes. For Stylo 184, the maximum shoot regeneration (29.5 ± 1.0 cm shoots/explant) and height (1.5 ± 0.1 cm) was achieved using 7 mg L-1 BA and 0.01 mg L-1 NAA. Direct and indirect shoot regeneration was obtained on the medium containing 1 mg L-1 BA and 0.01 mg L-1 NAA. The regeneration of shoots from callus of Stylo 184 varied between different genotypes and was high (2.6 to 5.8 shoots/explant) even after maintenance in culture of over three years. Both Cavalcade and Stylo 184 shoots were rooted on media supplemented with IBA (0 to 0.5 mg L-1) and readily transferred to soil (Stylo 184).Key words: Callus, forage legume, micropropagation, organogenesis, root induction
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