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Hierarchical recognition on the taxonomy of Nitzschia closterium f. minutissima
Juan Shi,KeHou Pan,XiaoQing Wang,Fang Chen,Mi Zhou,BaoHua Zhu,RenWei Qing
Chinese Science Bulletin , 2008, DOI: 10.1007/s11434-008-0080-4
Abstract: Nitzschia closterium f. minutissima, a marine eukaryotic unicellular diatom, originally classified as Bacillariophyta/Bacillariophyceae/Bacillariales/Bacillariaceae/Nitzschia, is one of the most important feed sources in mariculture. In this study, its morphological features were examined under DIC Microscopy (differential interference contrast microscope); its pigments and fatty acids composition were analyzed by using High Performance Liquid Chromatography (HPLC) and gas chromatography (GC); the complete Actin cDNA, part 18S rDNA, complete ITS1 and ITS2 sequences, part 28S rDNA sequences, and a putatively encoding Δ5 fatty acid desaturase gene were cloned respectively and further functioned in transgenic yeast. The sequence alignments were separately conducted using the related sequences from Nitzschia closterium f. minutissima, Cylindrotheca closterium (Bacillariophyta/Bacillariales/Bacillariaceae/Cylindrotheca) and Phaeodactylum tricornutum (Naviculales) with ClustalX 1.83. No distinct difference was discovered between N. closterium f. minutissima and P. tricornutum in both biochemical and molecular level. Their identity was more than 99.6% among 18S rDNA, 5.8S rDNA and actin-gene sequences, and is up to 98.6% even among ITS1 and ITS2 sequences. Their Δ5 desaturase similarity was 99.4%. However, the lower similarity was disclosured between N. closterium f. minutissima and Cylindrotheca closterium, which shared less than 40% identity in the ITS1 and ITS2 sequences. So, N. closterium f. minutissima should not be placed in Bacillariales, Bacillariaceae, Nitzschia, but in Naviculales, Phaeodactylaceae, Phaeodactylum, and it was actually a strain of P. tricornutum.
Hierarchical recognition on the taxonomy of Nitzschia closterium f. minutissima
SHI Juan,PAN KeHou,WANG XiaoQing,CHEN Fang,ZHOU Mi,ZHU BaoHua,QING RenWei,

科学通报(英文版) , 2008,
Abstract: Nitzschia closterium f. minutissima, a marine eukaryotic unicellular diatom, originally classified as Bacillariophyta/Bacillariophyceae/Bacillariales/Bacillariaceae/Nitzschia, is one of the most important feed sources in mariculture. In this study, its morphological features were examined under DIC Microscopy (differential interference contrast microscope); its pigments and fatty acids composition were analyzed by using High Performance Liquid Chromatography (HPLC) and gas chromatography (GC); the complete Actin cDNA, part 18S rDNA, complete ITS1 and ITS2 sequences, part 28S rDNA se- quences, and a putatively encoding ?5 fatty acid desaturase gene were cloned respectively and further functioned in transgenic yeast. The sequence alignments were separately conducted using the related sequences from Nitzschia closterium f. minutissima, Cylindrotheca closterium (Bacillariophyta/Baci- llariales/Bacillariaceae/Cylindrotheca) and Phaeodactylum tricornutum (Naviculales) with ClustalX 1.83. No distinct difference was discovered between N. closterium f. minutissima and P. tricornutum in both biochemical and molecular level. Their identity was more than 99.6% among 18S rDNA, 5.8S rDNA and actin-gene sequences, and is up to 98.6% even among ITS1 and ITS2 sequences. Their ?5 desaturase similarity was 99.4%. However, the lower similarity was disclosured between N. closterium f. minutis- sima and Cylindrotheca closterium, which shared less than 40% identity in the ITS1 and ITS2 se- quences. So, N. closterium f. minutissima should not be placed in Bacillariales, Bacillariaceae, Nitzschia, but in Naviculales, Phaeodactylaceae, Phaeodactylum, and it was actually a strain of P. tri- cornutum.
Ex-vitro establishment of Phalaenopsis amabilis seedlings in different substrates
Venturieri, Giorgini Augusto;Arbieto, Elsa Aurora Mendoza de;
Acta Scientiarum. Agronomy , 2011, DOI: 10.4025/actasciagron.v33i3.3950
Abstract: eight substrates were evaluated for ex-vitro establishment of phalaenopsis amabilis seedlings. they were: fibraflor? (commercial substrate), turfa fértil fg2? (commercial substrate), vermiculite, coconut fiber from the pericarp, decomposed pine bark, organic compost, sphagnum and shredded xaxim, in the establishment of seedlings of phalaenopsis amabilis l., in combination, with and without immersion of the seedlings, after they were removed from the growth flasks, in manzate 800 at a dosage of 1 g l1. the evaluated parameters were: the sum of the lengths of the two largest leaves, the sum of the lengths of the three largest roots and the percentage of surviving seedlings, evaluated at 190 days after planting. it was observed that there were significant differences between substrates, and sphagnum and shredded xaxim were the best in performance. the application of manzate 800 showed interaction with substrates, but the isolated effect was not significant. sphagnum is also an extractive product, but when it is impossible to obtain, an organic compost such as turfa fértil fg2? or fibraflor? can be used, with the necessary application of manzate 800.
Proliferaciones algales de la diatomea toxigénica Pseudo-Nitzschia (Bacillariophyceae) en el Golfo de Nicoya, Costa Rica  [cached]
Maribelle Vargas-Montero,Enrique Freer
Revista de Biología Tropical , 2004,
Abstract: En el mes de noviembre de 2001, se aisló de una marea roja cerca de la Isla San Lucas, las diatomeas Pseudo-Nitzschia pungens f. pungens seguida por Skeletonema costatum, Chaetoceros lorenzianus y en menor concentración Thalassiosira spp. las cuales fueron caracterizadas por microscopía electrónica de rastreo y transmisión, siendo esta la primera vez que se describe la presencia de estas especies produciendo proliferaciones en Costa Rica. Actualmente existe un aumento en el reporte de mareas rojas donde predominan las diatomeas, y los conteos celulares indican el aumento en el número de las especies conocidas como Pseudo-nitzschia pungens f. multiseries. A estas se les atribuye la producción del ácido domóico, un aminoácido de bajo peso molecular. Las intoxicaciones amnésicas por mariscos (IAM) que afectan a los humanos, se producen por la ingesta de mariscos contaminados con este ácido. En Costa Rica, hasta la fecha, solo se han reportado casos de intoxicación paralítica por mariscos contaminados por los dinoflagelados Pyrodinium bahamense var. compressum y Gymnodinium catenatum, sin embargo existe la posibilidad de producirse intoxicaciones humanas por la ingesta de mariscos y peces contaminados con toxinas amnésicas las cuales son hidrosolubles y termoestables. Debe entonces considerarse el peligro potencial de aparición de casos de intoxicaciones amnésicas y se sugiere la inclusión de estas especies en los programas de monitoreo permanente para tomar las medidas preventivas de salud pública Water samples were collected during a red tide event in November 2001, near San Lucas Island (Gulf of Nicoya, Costa Rica). Superficial temperature was 27oC and water was turbid, with no fetid smell. One sample was treated with negative staining and observed using a transmission electron microscope (TEM); another sample was observed using a scanning electron microscope (SEM). Samples had high concentrations of the diatom Pseudo-Nitzschia pungens f. pungens (characterized by two rows of poroids in the external channel), and lower concentrations of Skeletonema costatum (chains joined by external microtubules) and Chaetoceros lorenzianus (oval apertures and long chains, having setae with distinctive transverse rows and spines). This is the first time that the first species was described producing red tides in Costa Rica. However, reports about red tides with high concentration of species like P. pungens (variety multiseries) are increasing. These species have been related to the production of domoic acid, a low molecular weight amino acid which in humans can cause am
Análisis morfológico y toxicológico de cultivos de Pseudo-nitzschia pungens var. pungens (Bacillariophyceae) Morphological and toxicological analysis of cultures of Pseudo-nitzschia pungens var. pungens (Bacillariophyceae)  [cached]
Eugenia A. Sar,Darío Andrinolo,Inés Sunesen
Boletín de la Sociedad Argentina de Botánica , 2006,
Abstract: En el marco de un proyecto de monitoreo de especies de diatomeas nocivas llevado a cabo en el área norte del Golfo San Matías (Provincia de Río Negro, Argentina) hemos encontrado a Pseudo-nitzschia pungens (Grunow ex. P.T. Cleve) Hasle var. pungens y establecido cultivos monoclonales de esta variedad. Las cepas aisladas a partir de muestras tomadas con red, provenientes de Las Grutas y Piedras Coloradas (Golfo San Matías), fueron cultivadas en medio F/2 con adición de silicatos, y mantenidas a 20 oC con luz continua, blanca, fría. Los cultivos fueron analizados mediante Cromatografía Líquida de Alta Resolución (HPLC) para determinar si la variedad aislada era productora de ácido domoico (DA) en el área bajo estudio. Material procedente de campo y de cultivo fue estudiado con microscopios óptico y electrónico de barrido. Una comparación con los taxa más allegados, P . pungens var. cingulata Villac y P . multiseries (Hasle) Hasle, y datos sobre la morfología fina del material procedente de los cultivos, son presentados y discutidos. A pesar de que P . pungens var. pungens ha sido reportada como productora de ácido domoico, los resultados del análisis para detección de las toxinas fueron negativos para las cultivos chequeados. In the framework of a project of monitoring of harmful diatom species carried out in the Northern area of the Golfo San Matías (Provincia de Río Negro, Argentina) we found and established cultures of Pseudo-nitzschia pungens (Grunow ex. P.T. Cleve) Hasle var. pungens . The strains isolated from net phytoplankton samples obtained in Las Grutas and Piedras Coloradas, (Golfo San Matías) were cultured in F/2 medium, with silica added, and maintained at 20 oC, under continuous light supplied by cool-white fluorescent tubes. Cultures were essayed for domoic acid (DA) by High Performance Liquid Chromatography (HPLC). Materials from field and cultures were studied with light and scanning electron microscopy. Comparison with closely related taxa, P . pungens var. cingulata Villac and P . multiseries (Hasle) Hasle, and analysis of the fine morphology of cultured material, were conducted and discussed. In spite of P . pungens var. pungens has been reported as domoic acid producer, the toxin was not detected in any of the cultures tested.
Proliferaciones de Pseudo-nitzschia spp. (Bacillariophyceae) y otras especies del microplancton en la Bahía de Mazatlán, México  [cached]
Samuel Gómez-Aguirre,Sergio Licea,Samuel Gómez
Revista de Biología Tropical , 2004,
Abstract: Observaciones previas sobre el microplancton de la Bahía de Mazatlán, en el oto o de 1996, revelaron la existencia de altas densidades de Pseudo-nitzschia spp. Este mismo fenómeno se encontró en noviembre 1998 y un mes después se había desplazado al sur de la Bahía de Mazatlán, mientras que por esas mismas fechas, en California, EUA, se registraban accidentes de envenenamiento de mamíferos marinos, accidentes que en el noroeste de México se aprecian entre enero y marzo. Mensualmente se recolectaron muestras de agua superficial (< 0.5 m) y subsuperficial (10 m), de noviembre 1998 a enero 1999 y cada semana, entre febrero 1999 y mayo 2000; las muestras fueron analizadas por la técnica de Uterm hl a 400X. La cuantificación del microplancton presentó un amplio pulso invernal y otro menor en verano de cada ciclo anual. Con el empleo de microscopio electrónico (MEB y MET), se reconocieron cuatro especies de Pseudo-nitzschia y una más en estudio reciente. Las densidades de Pseudo-nitzschia fueron, en orden de importancia: 760 céls ml-1 (7 dic.1999), 610 (6 dic.1998), 335 (12 jul.1999), 198 (1o. feb. 1999), 170 (6 nov.1998), 123 (17 mar.1999), 108 (11 ago.1999). Otras especies de diatomeas (Thalassiosira spp., Asterionellopsis glacialis, Chaetoceros spp., Skeletonema costatum), dinoflagelados (Prorocentrum spp., Scripsiella trochoideda) y ciliados (Myrionecta rubra), manifestaron proliferaciones altas durante el período de este estudio Observations on microplankton in the autumn of 1996 revealed the existence of high densities of Pseudo-nitzschia spp. A similar phenomenon was found in November 1998 and November 1999 and a month later it shifted to the southern Mazatlán Bay while in California, USA, incidents of the poisoning of sea mammals were being recorded; this also happened on the Mexican Pacific coasts from January to March. Water samples collected at surface (<0.5 m deep) and subsurface (10 m deep) monthly, from November 1998 to January 1999 and every week from February 1999 to May 2000, were analyzed by the Uterm hl technique at 400 enlargements. Phytoplankton quantification showed winter and summer pulses; the 1998-1999 period was higher than the 1999-2000 period. Five species of Pseudo-nitzschia were identified by electron microscopy (TEM and SEM); a new study has revealed other species. High values of Pseudo-nitzschia were observed: 730 P-n/ml (Dec. 1999), 610 P-n/ml (Dec. 1998), 335 P-n/ml (Jul. 1999), 198 P-n/ml (Feb. 1999), 170 P-n/ml (Nov. 1998), 123 P-n/ml (Mar. 1999), 108 P-n/ml (Aug. 1999). The blooms of other species of diatoms (Thalassiosira
Biology of flowering and nectar production in the flowers of the beauty bush (Kolkwitzia amabilis Graebn.)
Marta Dmitruk
Acta Agrobotanica , 2012, DOI: 10.5586/aa.2012.017
Abstract: Nectar production and the morphology of the nectary and pollen grains of Kolwitzia amabilis Graebn. were studied during the period 2008–2009 and in 2011. The blooming of beauty bush flowers started in the third decade of May and ended in the middle of June; flowering lasted 22–23 days. The flower life span was 4–5 days. Nectar production began at the bud break stage. The tube of the corolla in beauty bush flowers forms a spur inside which the nectary is located. The secretory surface of the nectary consists of two layers of glandular epidermal outgrowths: unicellular trichomes, with their length ranging 54.6 μm – 70.2 μm, and papillae with a length of 13.0 μm – 20.6 μm. The mean weight of nectar per 10 flowers, determined for the three years of the study, was 8.6 mg, with a sugar concentration of 50.8%. The weight of nectar sugar was on average 4.4 mg. In terms of the size, beauty bush pollen grains are classified as medium-sized. These are tricolporate grains.
Ex-vitro establishment of Phalaenopsis amabilis seedlings in different substrates = Aclimatiza o “ex-vitro” de plantulas de Phalaenopsis amabilis em diferentes substratos
Giorgini Augusto Venturieri,Elsa Aurora Mendoza de Arbieto
Acta Scientiarum : Agronomy , 2011,
Abstract: Eight substrates were evaluated for ex-vitro establishment of Phalaenopsis amabilis seedlings. They were: Fibraflor (commercial substrate), Turfa Fértil FG2 (commercial substrate), vermiculite, coconut fiber from the pericarp, decomposed pine bark, organic compost, sphagnum and shredded xaxim, in the establishment of seedlings of Phalaenopsis amabilis L., in combination, with and without immersion of the seedlings, after they were removed from the growth flasks, in Manzate 800 at a dosage of 1 g L1. The evaluated parameters were: the sum of the lengths of the two largest leaves, the sum of the lengths of the three largest roots and the percentage of surviving seedlings, evaluated at 190 days after planting. It was observed that there were significant differences between substrates, and sphagnum and shredded xaxim were the best in performance. Theapplication of Manzate 800 showed interaction with substrates, but the isolated effect was not significant. Sphagnum is also an extractive product, but when it is impossible to obtain, an organic compost such as Turfa Fértil FG2 or Fibraflor can be used, with the necessary application of Manzate 800. Foram avaliados oito substratos na aclimata o “ex-vitro” de mudasde Phalaenopsis amabilis. Eles foram: Fibraflor (substrato comercial), Turfa Fértil FG2 (substrato comercial), vermiculita, casca de coco dilacerada, casca de pinheiro decomposta, composto organico, esfagno e xaxim desfibrado, para a aclimata o de plantulas de Phalaenopsis amabilis L., em combina o com e sem imers o das plantulas, logo após a retirada dos frascos de crescimento, em Manzate 800 na dosagem de 1 g L1. Os parametros avaliados foram: soma do comprimento das duas maiores folhas, a soma do comprimento das três maiores raízes e porcentagem de plantulas sobreviventes, avaliados aos 190 dias após o plantio. Observou-se que houve diferen as significativas entre substratos, sendo os de maior desempenho o esfagno e o xaxim desfibrado. A aplica o do Manzate 800 mostrou intera o com os substratos, mas o efeito isolado n o foi significativo. Na impossibilidade de ser obtido o esfagno, que também é um produto extrativo, poderiam ser usados: o composto organico, a Turfa Fértil FG2 ou o Fibraflor , com a necessária aplica o do Manzate 800.
The Hurst exponents of Nitzschia sp. diatom trajectories observed by light microscopy  [PDF]
J. S. Murguia,H. C. Rosu,A. Jimenez,B. Gutierrez-Medina,J. V. Garcia-Meza
Quantitative Biology , 2014, DOI: 10.1016/j.physa.2014.09.046
Abstract: We present the results of an experiment with light microscopy performed to capture the trajectories of live Nitzschia sp. diatoms. The time series corresponding to the motility of this kind of cells along ninety-five circular-like trajectories have been obtained and analyzed with the scaling statistical method of detrended fluctuation analysis optimized via a wavelet transform. In this way, we determined the Hurst parameters, in two orthogonal directions, which characterize the nature of the motion of live diatoms in light microscopy experiments. We have found mean values of these directional Hurst parameters between 0.70 and 0.63 with overall standard errors below 0.15. These numerical values give evidence that the motion of Nitzschia sp. diatoms is of persistent type and suggest an active cell motility with a kind of memory associated with long-range correlations on the path of their trajectories. For the collected statistics, we also find that the values of the Hurst exponents depend on the number of abrupt turns that occur in the diatom trajectory and on the type of wavelet, although their mean values do not change much
The influence of α-Naphtaleneacetic Acid (NAA) on somatic embryogenesis moon orchid Phalaenopsis amabilis (L.) Bl.  [PDF]
EDY SETITI WIDA UTAMI,ISSIREP SUMARDI,TARYONO,ENDANG SEMIARTI
Biodiversitas , 2007,
Abstract: An experiment to analyze the effect of plant growth regulator α-Naphtaleneacetic Acid (NAA) on somatic embryogenesis moon orchid Ph amabilis (L.) Bl. was carried out. One year old of plantlets were used as explants sources. Basal leaf of these explants were cultured in medium New Phalaenopsis (NP) added with 0,1 mg/L, 1 mg/L, 2 mg/L, 3 mg/L, and 4 mg/L NAA. The explants were cultured in medium NP without NAA were used as control. The formation of embryogenic callus was observed every day, while the formation of somatic embryo was observed every week for 6 week using a dissecting microscope. The result showed that somatic embryogenesis Ph amabilis (L.) Bl were influenced by plant growth regulator NAA. Explants were cultured in medium NP without NAA didn’t embryo formed, while explants were cultured in medium NP added with 2 mg/L, 3 mg/L, and 4 mg/L NAA embryo formed at embryogenic callus appear. These somatic embryos formed as an indirect via callus phase.
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