MOSP - Macao Scientific Publishers

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In Vitro Regeneration of Hybrid Cashew Plantlets (Anacardium occidentale L.) via Embryo Culture Techniques

Aliyu, O. M.* and Awopetu J.A.

Abstract: Embryos from immature nuts of cashew (Anacardium occidentale L.) were cultured in vitro to regenerate improved hybrid plantlets. Explants (embryo) were excised from developing F1 hybrid immature nuts derived from diallel cross and harvested at 2-, 4-, 6- and 8-weeks after pollination (WAPo) for in vitro culture. The explants were surface sterilized, aseptically dissected and cultured into pure basal Murashige and Skoog (MS) agar medium and MS medium supplemented with 1 mM each of naphthaleneacetic acid (NAA), benzyladenine (BA) and gibberellic acid (GA3) and subsequently observed for germination and survival rates until successful ones were transferred to the field. Age of explants was found to significantly influence both the germination and survival rates. Explants of 6 weeks old and above were found to give better germination rate and highest survival percentage in this study. Only MS medium supplemented with 1 mM of gibberellic acid (MS+GA3) supported germination and growth at 2-WAPo, suggesting the essentiality of GA3 as a growth regulator to a very young cashew embryo. Analysis also showed that factors such as medium composition, age of embryo and genotype (accession) significantly influence the germination rate of cashew embryo. It was observed that cashew embryos were found to be autonomy of growth regulator as the age increases and medium composition is only critical at very young age of the embryo. Successful germinated explants simultaneously produced shoot and root and were ready for transfer to field and acclimatization, between 90 and 112 days after inoculation.[...] Read More.

Keywords: Anacardium occidentale, in vitro culture, explant, embryo.

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Exploring Callus Proliferation and Somatic Embryogenesis in Gossypium hirsutum L.

Ikram-ul-Haq

Abstract: Somatic embryogenesis and plant regeneration are fundamental to tissue culture biotechnology in cotton (Gossypium hirsutum L.) cv. Coker 312. Callus proliferation was considered best on MS1a (2.0 mg/L NAA; 0.1 mg/L ZT; 0.1 mg/L KT) when 6 weeks old callus was cultured from MS1b (0.1 mg/L 2, 4- D; 0.5 mg/L KT) medium, there is no need to select embryogenic calli for somatic embryogenesis, as all of them were converted to somatic embryos. NH4NO3 play an important role in differentiation of callus into somatic embryos but is lethal for embryos just after two weeks. However, KNO 3 is less efficient for somatic embryo induction but is best for embryo maturation. By this procedure 56.51% cotyledenary embryos were developed within 5 weeks. Of that, 82.05% cotyledenary embryos were developed not only into normal plantlets, but rooted simultaneously when cultured on MS (with 0.05 mg/L GA3) medium. A complete plant of Cocker-312 could be regenerated through somatic embryogenesis within 4 to 5 months.[...] Read More.

Keywords: Gossypium hirsutum L,plant regeneration, Coker 312, callus induction, somatic embryogenesis, in vitro regeneration.

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Evaluating Growth Regulator Effects on Two Differently Cultured Explants of Carapa guianensis in vitro

Larisse Lobo de Oliveira, Anaíze Borges Henriques, Andrea Furtado Macedo,*

Abstract: Carapa guianensis Aubl. (Meliaceae), known locally as andiroba, is a multi-use species from Amazonia. Andiroba oil is considered an important natural product in the Brazilian market, and international demand is increasing due to its cosmetic and pharmaceutical potential. C. guianensis trees produce seed irregularly over different harvest periods, leading to inconsistent oil production and difficulties with supply. No management plans or protocols have been developed for in vitro or clonal production of Carapa seedlings and the maintenance of genetic resources. The objective of this study was to assess the effect of growth regulators on explants (young leaves, old leaves and apical buds). Explants consisting of leaf segments 1 cm on a side were cultivated in MS medium with and without growth regulators. Evaluation was based on fresh and dry weight of the explants after 20 days. In the media with 2,4-dichlorophenoxyacetic acid (5, 15, 35 or 45 µM), changes were observed in weight and explant appearance (callus). Bud breakage and development of shoots were achieved using 5 µM of 6-benzylaminopurine. Overall, the results showed that 2,4-dichlorophenoxyacetic acid stimulates callus formation on andiroba foliar explants, while 6-benzylaminopurine was superior to thidiazuron for the initial development of shoots.[...] Read More.

Keywords: Growth regulators, Carapa guianensis, in vitro, tissue culture, organogenesis.

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Optimizing Blastocyst Formation from Cryopreserved Mouse Two-Cell Embryos: The Role of Fibroblast and Hepatocyte Growth Factors

Fatemeh Ghasemian, Mahnaz Azarnia, Abtin Heidarzadeh, Shervin Ghadarjani and Mohammad Hadi Bahadori*

Abstract: There is great need to improve our understanding of what increases an embryo’s development potential, after vitrification-thawing processes. For this subject, 358 two-cell stage embryos were collected from oviduct of pregnant two-day old mice and vitrified. After thawing, embryos were cultured in Tyrode's (T6) medium supplemented with different doses of fibroblast growth factor (FGF; 0, 10, 20, 50 and 100 ng/ml) and hepatocyte growth factor (HGF; 0, 10, 20, 50 and 100 ng/ml) until the blastocyst stage. To determine quality of blastocysts, blastocysts were stained with hoechst and propidium iodide. After culture for 24 h, 92.65% of treated embryos with 20 ng/ml of FGF had higher (P64 cells had a significantly higher inner cell mass (ICM) in comparison to the control group (P< 0.01). In conclusion, in this experiment, addition of growth factors in the culture had favorable effects on post-thawed cleavage of vitrified 2-cell embryos and blastocyst quality. Keywords: Blastocyst quality, growth factors, preimplantation development, vitrification. [...] Read More.

Keywords: Blastocyst quality, growth factors, preimplantation development, vitrification.

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Direct Detection of Salmonella InvA, SpiC, and SipC in Clinical Samples Using Dot Blot Hybridization

Hang’ombe Bernard Mudenda*, Ulaya William, Mwansa James C. L., Mubita Charles, Isogai Nayuta, Mulenga Evans, Moonga Ladslav, Isogai Hiroshi and Isogai Emiko

Abstract: Pathogenesis of Salmonella depends upon a large number of factors controlled by an array of genes that synergise into actual virulence. The goal of this study was to detect Salmonella invA, spiC and sipC directly from clinical specimens, using the dot blot hybridization assay. We detected invA , spiC and sipC as a one combination from 4.5% (95% CI: 2.21 to 8.64) human feacal and 35.2% (95% CI: 26.4 to 45.0) poultry samples after enrichment. Furthermore the dot blot method had a higher sensitivity than routine culture, before and after enrichment. These results indicate that dot blot hybridization may be used to directly detect Salmonella invA, spiC and sipC in clinical samples.[...] Read More.

Keywords: Salmonella, dot-blot hybridization, spiC, sipC, invA, clinical-samples.

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Genetic Variability of Helicobacter pylori in Iran: Clarithromycin Resistance and 23S rRNA Mutations

Mohammad Kargar*, Maryam Baghernejad, Abbas Doosti and Sadegh Ghorbani-Dalini,

Abstract: To determine the 23S rRNA point mutations in clarithromycin resistance of Helicobacter pylori strains isolated from southwest, Iran. This was a cross-sectional survey, which was done on 263 patients who referred to endoscopy department of Shehrekord university of medical sciences. According to gram stain, urease, catalase, oxidase and polymerase chain reaction (PCR) H. pylori identified. Standard National Committee for Clinical Laboratory Standard (NCCLS) method used for assessment of clarithromycin resistance. Specific primers and restriction enzymes BsaI and MboII by PCR-RFLP were used for analysis of A2143G and A2142G mutations. So for the detection of A2142C, specific primers and PCR method were used. 84 strains of H. pylori (31.94%) determined by PCR method. Of 19 (22.62%) clarithromycin resistant strains 13 (68.40%), 3 (15.78%), 2 (10.52%) had A2143G, A2142G, A2142C respectively and one unknown mutation in 23S rRNA gene. Because of considerable resistance to clarithromycin, direct diagnosis of this mutation by molecular approach in other parts of the country is necessary.[...] Read More.

Keywords: Polymerase chain reaction, clarithromycin, resistance, 23S rRNA, polymerase chain reaction - restriction fragment length polymorphism.

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Rapid and Accurate Detection of Agrobacterium tumefaciens in Soil Using PCR

Wei Yang, Lei Ji, Li-Rong Tan, Shi-Mo Li, Yan Wang, Hong-Xia Liu*, and Yu-Ming Luo*

Abstract: One pair of primers was designed based on the sequence of tmr locus for specific and sensitive detection of Agrobacterium tumefaciens. Only the A. tumefaciens strain can produce the 236bp target fragment among the fourteen bacterial species that tested. The sensitivity of the specific PCR system was determined by a nested-PCR amplification which can numbered the copies of the template DNA. According to the results, it can give positive band when only 100 copies were in the template. The protocol was carried out for detection A. tumefaciens of twelve soil samples collected from six different gardens in Shanghai where crown gall happened. Two of the samples which collected from symptomless gardens also give the positive band. Based on the results we can make a conclusion that this pair of primers can be a useful tool in detecting A. tumefaciens, especially in detecting latent infection of this devastating pathogen.[...] Read More.

Keywords: Agrobacterium tumefaciens, detection, polymerase chain reaction (PCR).

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Assessing Genetic Relationships and Population Differentiation in Karakul Sheep Using Microsatellite Markers

Shahram Nanekarani*, Cyrus Amirinia and Nour Amirmozafari

Abstract: In this study, the genetic variation in Karakul sheep was investigated using 15 microsatellite markers (MCMA2, BMS460, BM1815, OARCP26, OARFCB20, MAF64, OARAE129, BMS332, LSCV38, BM6444, BMS995, MCMA26, BMS678 and OARCP49) and all fifteen loci were amplified successfully. Genomic DNA was extracted from 120 blood samples, using modified salting-out method. Tests of genotype frequencies for deviation from the Hardy-Weinberg equilibrium (HWE) were performed at each locus and revealed significant departure from HWE (P < 0.001) due to heterozygote excess. Parameters of variability such as effective number of alleles and gene diversities corroborated with the high level of variation frequently displayed by microsatellite markers. The fifteen tested loci were all polymorphic. Furthermore, other criteria of genetic variation including polymorphism information content (PIC) values and Shanon information index were calculated in this study. Results showed that, high level of genetic diversity was observed in Karakul breed and this breed was not at risk for conservation concept. This research has also shown that microsatellite technique is a useful tool for evaluation of genetic variation among domesticated animals.[...] Read More.

Keywords: Karakul sheep, microsatellite markers, genetic variation, polymorphism. Hardy-Weinberg equilibrium (HWE).

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Harnessing Wastewater Microbes for Polyhydroxybutyrate Production: A Case Study with Enterobacter aerogenes 12Bi

Nur Ceyhan* and Guven Ozdemir

Abstract: A strain of poly- -hydroxybutyrate (PHB)-accumulating bacterium was isolated and identified as Enterobacter aerogenes (designated E. aerogenes 12Bi) by using biochemical and phylogenetic characterization. The accumulation of a large amount of granules in its cells cultured in the domestic wastewater medium (DWWM) were showed by transmission electron microscopy (TEM). When PHB production by our strain was determined by Hypochlorite method, it was found that PHB production ranged from 16.66 to 96.25% (w/w). The highest PHB yield by our microorganism was up to 96.25% within 18 h in DWWM 5 (supplemented with 100% DWW). This is the first report of the use of DWW for production of PHB by E. aerogenes. The results obtained in the study demonstrated that PHB could be efficiently produced to a high concentration with high productivity by using DWWM as an inexpensive substrate. Thus, it can contribute to the reduction of high production cost of PHB.[...] Read More.

Keywords: Poly- -hydroxybutyrate (PHB), bioplastics, domestic wastewater, Enterobacter aerogenes, biochemical identification, phylogenetic identification.

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Exploring the antimicrobial efficacy of Carica papaya L. root extracts

Doughari, J. H.*, Elmahmood, A. M. and Manzara, S.

Abstract: The bioactive compounds of root extracts of Carica papaya L. were extracted, using water and organic solvents, and were investigated for antibacterial activity against some pathogenic bacteria using the cup plate agar diffusion method. The aqueous extracts did not show significant activity, but the organic extracts had significant activity with the methanol extracts demonstrating the highest activity against the test bacteria. The extracts demonstrated higher activities against all the gram-negative bacteria than the gram-positive bacteria tested, with the highest activity (14 mm zone of inhibition) demonstrated against Salmonella typhi. Increase in temperature enhanced the activity of the extracts, while alkaline pH decreased the activity. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts ranged between 50-200 mg/ml. Preliminary phytochemical analyses showed that the extracts contain alkaloids, tannins, saponins, glycosides and phenols. Carica papaya may be used for the treatment of gastroenteritis, uretritis, otitis media, typhoid fever and wound infections.[...] Read More.

Keywords: Carica papaya L., antibacterial activity, phytochemical analysis, antibiotics.

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