The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
William J. Green - One of the best experts on this subject based on the ideXlab platform.
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Rare earth elements in the water column of Lake Vanda, McMurdo Dry Valleys, Antarctica
Geochimica et Cosmochimica Acta, 2002Co-Authors: Eric Heinen De Carlo, William J. GreenAbstract:Abstract We present data on the composition of water from Lake Vanda, Antarctica. Vanda and other lakes in the McMurdo Dry Valleys of Antarctica are characterized by closed basins, permanent ice covers, and deep saline waters. The meromictic lakes provide model systems for the study of trace metal cycling owing to their pristine nature and the relative simplicity of their biogeochemical systems. Lake Vanda, in the Wright Valley, is supplied by a single input, the Onyx River, and has no output. Water input to the lake is balanced by sublimation of the nearly permanent ice cap that is broken only near the shoreline during the austral summer. The water column is characterized by an inverse thermal stratification of anoxic warm hypersaline water underlying cold oxic freshwater. Water collected under trace-element clean conditions was analyzed for its dissolved and total rare earth element (REE) concentrations by inductively coupled plasma mass spectrometry. Depth profiles are characterized by low dissolved REE concentrations (La, Ce,
Michael T. Madigan - One of the best experts on this subject based on the ideXlab platform.
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Cold-Active, Heterotrophic Bacteria from the Highly Oligotrophic Waters of Lake Vanda, Antarctica
Microorganisms, 2015Co-Authors: Nicole A. Vander Schaaf, Anna M. G. Cunningham, Brandon P. Cluff, Codyjo K. Kraemer, Chelsea L. Reeves, Carli J. Riester, Lauren K. Slater, Michael T. Madigan, W. Matthew SattleyAbstract:The permanently ice-covered lakes of the McMurdo Dry Valleys, Antarctica are distinctive ecosystems that consist strictly of microbial communities. In this study, water samples were collected from Lake Vanda, a stratified Dry Valley lake whose upper waters (from just below the ice cover to nearly 60 m) are highly oligotrophic, and used to establish enrichment cultures. Six strains of psychrotolerant, heterotrophic bacteria were isolated from lake water samples from a depth of 50 or 55 m. Phylogenetic analyses showed the Lake Vanda strains to be species of Nocardiaceae, Caulobacteraceae, Sphingomonadaceae, and Bradyrhizobiaceae. All Lake Vanda strains grew at temperatures near or below 0 °C, but optimal growth occurred from 18 to 24 °C. Some strains showed significant halotolerance, but no strains required NaCl for growth. The isolates described herein include cold-active species not previously reported from Dry Valley lakes, and their physiological and phylogenetic characterization broadens our understanding of these limnologically unique lakes.
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A Halophilic Bacterium Inhabiting the Warm, CaCl2-Rich Brine of the Perennially Ice-Covered Lake Vanda, McMurdo Dry Valleys, Antarctica
Applied and environmental microbiology, 2015Co-Authors: George S. Tregoning, Megan L. Kempher, Deborah O. Jung, Vladimir A. Samarkin, Samantha B. Joye, Michael T. MadiganAbstract:Lake Vanda is a perennially ice-covered and stratified lake in the McMurdo Dry Valleys, Antarctica. The lake develops a distinct chemocline at about a 50-m depth, where the waters transition from cool, oxic, and fresh to warm, sulfidic, and hypersaline. The bottom water brine is unique, as the highly chaotropic salts CaCl2 and MgCl2 predominate, and CaCl2 levels are the highest of those in any known microbial habitat. Enrichment techniques were used to isolate 15 strains of heterotrophic bacteria from the Lake Vanda brine. Despite direct supplementation of the brine samples with different organic substrates in primary enrichments, the same organism, a relative of the halophilic bacterium Halomonas (Gammaproteobacteria), was isolated from all depths sampled. The Lake Vanda (VAN) strains were obligate aerobes and showed broad pH, salinity, and temperature ranges for growth, consistent with the physicochemical properties of the brine. VAN strains were halophilic and quite CaCl2 tolerant but did not require CaCl2 for growth. The fact that only VAN strain-like organisms appeared in our enrichments hints that the highly chaotropic nature of the Lake Vanda brine may place unusual physiological constraints on the bacterial community that inhabits it.
Eric Heinen De Carlo - One of the best experts on this subject based on the ideXlab platform.
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Rare earth elements in the water column of Lake Vanda, McMurdo Dry Valleys, Antarctica
Geochimica et Cosmochimica Acta, 2002Co-Authors: Eric Heinen De Carlo, William J. GreenAbstract:Abstract We present data on the composition of water from Lake Vanda, Antarctica. Vanda and other lakes in the McMurdo Dry Valleys of Antarctica are characterized by closed basins, permanent ice covers, and deep saline waters. The meromictic lakes provide model systems for the study of trace metal cycling owing to their pristine nature and the relative simplicity of their biogeochemical systems. Lake Vanda, in the Wright Valley, is supplied by a single input, the Onyx River, and has no output. Water input to the lake is balanced by sublimation of the nearly permanent ice cap that is broken only near the shoreline during the austral summer. The water column is characterized by an inverse thermal stratification of anoxic warm hypersaline water underlying cold oxic freshwater. Water collected under trace-element clean conditions was analyzed for its dissolved and total rare earth element (REE) concentrations by inductively coupled plasma mass spectrometry. Depth profiles are characterized by low dissolved REE concentrations (La, Ce,
Sri Hartati - One of the best experts on this subject based on the ideXlab platform.
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UJI TINGKAT KOMPATIBILITAS DAN UMUR MEKAR BUNGA PADA PERSILANGAN INTERGENERIK ANGGREK Vanda sp DAN Phalaenopsis sp
Caraka Tani: Journal of Sustainable Agriculture, 2018Co-Authors: Sri Hartati, Ongko Cahyono, Nunik Puji LestariAbstract:The study aims to determine the effect of compatibility level to the intergeneric crossing ability and the age of the flower blooming of Vanda sp and Phalaenopsis sp. Research was conducted at a screen house and Plant Breeding Laboratory of Faculty of Agriculture, Sebelas Maret University. Crossing is done by inserting pollen of male parent to the stigma of the female parent which were selected based on a predetermined number of crosses. The observations included: percentage of successful crosses, time of fruit formation, durability of hanging fruit, the percentage of fruit ready for harvest, the percentage of the fallen fruit, and the level of compatibility. The study concluded that the intergeneric cross between Vanda sp and Phalaenopsis sp can be done until the age of 3 weeks after the flowers bloom. The fruit begins to form at the age of 6-12 day after crosses (DAC) and can be harvested after reaching the age of about three months. The intergeneric cross between Vanda sp and Phalaenopsis sp is compatible, because this was capable of producing the fruit of more than 60%.
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keragaan anggrek persilangan Vanda celebica x Vanda dearei hasil iradiasi sinar gamma
Agrotechnology Research Journal, 2017Co-Authors: Sri Hartati, Ahmad Yunus, Fajar NugrohoAbstract:Variation on orchid is an advantage that allows plant as breeding material. Orchid in plant breeding has a target to increase plant genetic diversity character who favored by the consumer. Efforts to increase genetic diversity among others by artificial mutation using gamma ray irradiation. This research aims to study the influence of gamma ray irradiation dose against the performance of morphology and growth of crossbred orchids ♀Vanda celebica x ♂Vanda dearei. Research using completely randomized design single factor that is dose gamma ray irradiation 0 Gray, 10 Gray, 20 Gray, 30 Gray, 40 Gray and 50 Gray. Data were analyzed descriptively, compared plant irradiation treatments with control plants to determine the effect of irradiation on morphology and growth plant. The results showed dose irradiation treatment increased the diversity of plant height, leaf amount, leaf length, leaf color changes, the amount and length of roots. 10 Gray dose irradiation increases as height and length plant leave. 30 Gray dose irradiation increase in the number of leaves. Leaf color change occurs at 20 irradiation treatments Gray and 50 Gray.
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Keragaan Anggrek Persilangan ♀ Vanda Celebica X ♂ Vanda Dearei Hasil Iradiasi Sinar Gamma
Agrotechnology Research Journal, 2017Co-Authors: Sri Hartati, Ahmad Yunus, Fajar NugrohoAbstract:Variation on orchid is an advantage that allows plant as breeding material. Orchid in plant breeding has a target to increase plant genetic diversity character who favored by the consumer. Efforts to increase genetic diversity among others by artificial mutation using gamma ray irradiation. This research aims to study the influence of gamma ray irradiation dose against the performance of morphology and growth of crossbred orchids ♀Vanda celebica x ♂Vanda dearei. Research using completely randomized design single factor that is dose gamma ray irradiation 0 Gray, 10 Gray, 20 Gray, 30 Gray, 40 Gray and 50 Gray. Data were analyzed descriptively, compared plant irradiation treatments with control plants to determine the effect of irradiation on morphology and growth plant. The results showed dose irradiation treatment increased the diversity of plant height, leaf amount, leaf length, leaf color changes, the amount and length of roots. 10 Gray dose irradiation increases as height and length plant leave. 30 Gray dose irradiation increase in the number of leaves. Leaf color change occurs at 20 irradiation treatments Gray and 50 Gray.
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The intergeneric crossing of Phalaenopsis sp. and Vanda tricolor
2014Co-Authors: Sri HartatiAbstract:To study the intergeneric crossing between orchids of Phalaenopsis sp. and Vanda tricolor, three species of Phalaenopsis sp. (Phalaenopsis Joane Kileup June, Phalaenopsis Pinlong Cinderella, and (Phal. Fortune Buddha x Phal. Princess Kaiulani) were crossed reciprocally with Vanda tricolor in time-different value (within the first, second and third week after full opened flower). The crossing of Phalaenopsis sp. and Vanda tricolor was compatible, and the use of Phalaenopsis sp. as male parent had better probability in producing fruits rather than the opposite. The crossing which was done at the first and the second weeks after blooming produced more fruit than the crossing at the third week after blooming, even though it did not affect the success of crossing, time of fruit formation, and duration of fruit hanging. Key words: Intergeneric Crossing, Orchids, Phalaenopsis sp., Vanda tricolor
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PERBAIKAN GENETIK ANGGREK ALAM Vanda spp MELALUI PERSILANGAN INTERSPESIFIK DALAM MENDUKUNG PERKEMBANGAN ANGGREK DI INDONESIA (Vanda spp Orchid Culture through Genetic Improvement Interspecific Crosses in Support of Orchid Developments in Indonesia)
2014Co-Authors: Sri Hartati, Ongko CahyonoAbstract:Efforts to improve the genetic quality of orchids have constraints on seed propagation techniques crosses and from crosses. The study aims to: (1) obtain a cross technique that can produce seeds with high fertility rates, (2) to obtain a new hybrid character which has advantages in flower. The study was conducted at the Center for Plant Conservation Kebun Raya Bogor LIPI. Research was an interspecific crosses that ♀ Vanda celebica x ♂ Vanda tricolor, ♀ Vanda celebica x ♂ Vanda dearei, ♀ Vanda celebica x ♂ Vanda insignis. And crosses the reciprocal is ♀ Vanda tricolor x ♂ Vanda celebica, ♀ Vanda dearei x ♂Vanda celebica, ♀ Vanda insignis x ♂Vanda celebica. Crosses performed by crossing parent elected as male or female parent. Activities include characterization of elders, crosses, harvesting, seed dispersal, seed Deployment and transfer done aseptically in tissue culture laboratory. Observations included the successful crossing, when formed fruit, ripe fruit, and formed protokorm. Of research produced 5 series hybrid to form protokorm is Vanda dearei x Vanda Celebica, Vanda celebica x Vanda dearei, Vanda insignis x Vanda celebica, Vanda celebica x Vanda insignis, Vanda celebica x Vanda tricolo. The success of crosses 33%100%, time required for seed maturation varies between 122-262 days, 16-23 days old germinated.
Chiang Shiong Loh - One of the best experts on this subject based on the ideXlab platform.
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Endopolyploidy in Vanda Miss Joaquim (Orchidaceae)
New Phytologist, 2003Co-Authors: Wan Li Lim, Chiang Shiong LohAbstract:Summary • Occurrence of endopolyploidy in somatic tissues of the hybrid orchid Vanda Miss Joaquim (Vanda hookeriana × Vanda teres) was investigated with respect to tissue type and developmental stage. Effects of naphthaleneacetic acid (NAA) and gibberellic acid (GA3) on endopolyploidy during embryo development were also studied. • For the study of endopolyploidy, flow cytometric analysis was employed to determine nuclear DNA content of cells of somatic tissues. • Multiploid cells were observed in leaves, roots and column, but not in shoot apex, stem, perianth and pedicel. Furthermore, differential distribution of multiploid cells was found among different parts of leaves and roots. The degree of endopolyploidy in embryos increased with development. NAA was shown to induce endoreduplication in germinating embryos to a much larger extent than GA3. • The pattern of endopolyploidy was characteristic of tissue type and developmental stage. The implications of endopolyploidy during differentiation and development, as well as the relevance of endopolyploidy to somaclonal variation, are discussed.
