Cryopreservation of plant germplasm in Argentina

This review describes the current status of development of methods for cryopreservation (at -196ºC) of plants germplasm in Argentina. Arachis pintoi, a forage legume, has been maintained as seeds using vitrification method. Additionally, apical meristems, shoot tips, and somatic embryos have been cryopreserved using encapsulation-dehydration. Zygotic embryos, encapsulated and dehydrated, have permitted the cryopreservation of seven species of the genus Ilex. Various explants (apical meristems, uninodal segments, buds and somatic embryos) of Melia azedarach have been cryopreserved using the encapsulation-dehydration method. Protocols based in encapsulation-dehydration have also been developed for shoot tips of Citrus sinensis, seeds and protocorms of Oncidum bifolium and anthers of Oryza sativa. Vitrification protocols have been developed forcryopreservation of shoot tips of Solanum tuberosum and seeds of Toona ciliata.Fil: Mroginski, Luis Amado. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Rey de Badaró, Hebe Yolanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Regeneration of plants from apical meristem tips and nodal segments of Arachis pintoi

The in vitro regeneration potential of shoot apical tips (2 to 3 mm in length), meristems (0.3 to 0.5 mm in length), and nodal segments (4 to 7 mm long with an axillary bud) of diploid (2n = 2x = 20) and triploid (2n = 3x = 30) cytotypes of Arachis pintoi was evaluated. Explants were cultured on MS medium supplemented with different concentrations and combinations of naphthaleneacetic acid (NAA) and benzyladenine (BA). In one experiment the effect of gibberellic acid was tested. The cultures were done in liquid and solid media. Plant regeneration can be readily achieved from all explants in one step of 30 d culture on MS + 0.01 mg/L each of NAA and BA or two steps consisting of 1) shoots regeneration through culture of explants on MS + 0.01 mg/L each of NAA and BA, and 2) induction of rooting in regenerated shoots by reculture on MS + 0.01 mg/L NAA. The plantlets were successfully transferred to pots in a greenhouse.Fil: Rey de Badaró, Hebe Yolanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Mroginski, Luis Amado. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Organogenesis and plant regeneration of Arachis villosa Benth. (Leguminosae) through leaf culture

With the aim of developing an efficient plant regeneration protocol, leaflet explants of three accessions of Arachis villosa Benth. (S2866, S2867 and L97) were cultured on basic Murashige and Skoog medium supplemented with different combinations of plant growth regulators: α-naphthalenacetic acid, indole-3-butyric acid, 6-benzylaminopurine, kinetin and thidiazuron. The accession L97 was the only one able to differentiate buds through indirect organogenesis. The most suitable combination for bud regeneration was the basic medium added with 13.62 μM thidiazuron and 4.44 μM 6-benzylaminopurine. These results show the important role of the genotype in morphogenetic responses and the organogenetic effect of thidiazuron in Arachis villosa accession L97. A thidiazuron lacking media (only 0.54 μM α-naphthalenacetic acid, 13.95 μM kinetin and 13.32 μM 6-benzylaminopurine were added) promoted the elongation of the regenerated buds. Adventitious rooting was achieved 90 days after the isolated shoots were transferred to a rooting medium containing 0.54 μM α-naphthalenacetic acid.Fil: Fontana, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Mroginski, Luis Amado. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Rey de Badaró, Hebe Yolanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

High performance reduced order modeling techniques based on optimal energy quadrature: application to geometrically non-linear multiscale inelastic material modeling

A High-Performance Reduced-Order Model (HPROM) technique, previously presented by the authors in the context of hierarchical multiscale models for non linear-materials undergoing infinitesimal strains, is generalized to deal with large deformation elasto-plastic problems. The proposed HPROM technique uses a Proper Orthogonal Decomposition procedure to build a reduced basis of the primary kinematical variable of the micro-scale problem, defined in terms of the micro-deformation gradient fluctuations. Then a Galerkin-projection, onto this reduced basis, is utilized to reduce the dimensionality of the micro-force balance equation, the stress homogenization equation and the effective macro-constitutive tangent tensor equation. Finally, a reduced goal-oriented quadrature rule is introduced to compute the non-affine terms of these equations. Main importance in this paper is given to the numerical assessment of the developed HPROM technique. The numerical experiments are performed on a micro-cell simulating a randomly distributed set of elastic inclusions embedded into an elasto-plastic matrix. This micro-structure is representative of a typical ductile metallic alloy. The HPROM technique applied to this type of problem displays high computational speed-ups, increasing with the complexity of the finite element model. From these results, we conclude that the proposed HPROM technique is an effective computational tool for modeling, with very large speed-ups and acceptable accuracy levels with respect to the high-fidelity case, the multiscale behavior of heterogeneous materials subjected to large deformations involving two well-separated scales of length.Peer ReviewedPostprint (author's final draft

Probing the Structure of [NiFeSe] Hydrogenase with QM/MM Computations

The geometry and vibrational behavior of selenocysteine [NiFeSe] hydrogenase isolated from Desulfovibrio vulgaris Hildenborough have been investigated using a hybrid quantum mechanical (QM)/ molecular mechanical (MM) approach. Structural models have been built based on the three conformers identified in the recent crystal structure resolved at 1.3 Å from X-ray crystallography. In the models, a diamagnetic Ni2+ atom was modeled in combination with both Fe2+ and Fe3+ to investigate the effect of iron oxidation on geometry and vibrational frequency of the nonproteic ligands, CO and CN-, coordinated to the Fe atom. Overall, the QM/MM optimized geometries are in good agreement with the experimentally resolved geometries. Analysis of computed vibrational frequencies, in comparison with experimental Fourier-transform infrared (FTIR) frequencies, suggests that a mixture of conformers as well as Fe2+ and Fe3+ oxidation states may be responsible for the acquired vibrational spectra.DFG, 390540038, EXC 2008: UniSysCatDFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität BerlinEC/H2020/810856/EU/Twin to Illuminate Metals in Biology and Biocatalysis through Biospectroscopy/TIMB

Enhanced seed germination of Ilex dumosa R. (Aquifoliaceae) through in vitro culture of cut pyrenes

An in vitro culture protocol was developed that increased the germination percentage and decreased the lag time to germination for Ilex dumosa R. pyrenes as a tool for replacing the laborious task of embryo rescue technique. This method involves transversely cutting surface-sterilized pyrenes with a scalpel blade, then placing the micropylar one-third end with the rudimentary embryo (0.25 mm long) on solidified (agar 0.65%) quarter-strength salts and vitamins of Murashige and Skoog, 1962 medium with 3% sucrose, and incubating in a growth room at 27 ± 2 8C with a 14-h photoperiod (116 mmolm?2 s?1). Most of the cut pyrenes (greater than 50%) germinated within the first month after inoculation and achieved maximum germination (70%) in 2 months compared with whole pyrenes, which began to germinate 3 months after sowing and required more than 8 months for maximum germination (37%). Moreover, the germination percentage of cut pyrenes was significantly higher than the germination of isolated embryos (34%). Thus, the cut pyrenes culture is a simpler and more effective technique than embryo rescue. Easily, on average, a trained operator is able to culture ~1000 cut pyrenes per day instead of ~100 isolated embryos.Fil: Dolce, Natalia Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Mroginski, Luis Amado. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Rey, Hebe Yolanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentin

Insights into the structure of the active site of the O-2-tolerant membrane bound [NiFe] hydrogenase of R. eutropha H16 by molecular modelling

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Structural models for the Ni-B state of the wild-type and C81S protein variant of the membrane-bound [NiFe] hydrogenase from Ralstonia eutrophaH16 were derived by applying the homology model technique combined with molecular simulations and a hybrid quantum mechanical/molecular mechanical approach. The active site structure was assessed by comparing calculated and experimental IR spectra, confirming the view that the active site structure is very similar to those of anaerobic standard hydrogenases. In addition, the data suggest the presence of a water molecule in the second coordination sphere of the active centre.DFG, EXC 314, Unifying Concepts in Catalysi

Thermodynamic gradient-based poroplastic theory for concrete under high temperatures

Concrete materials subjected to long term exposures to high temperatures suffer severe degradations in its mechanical properties (cohesion, friction, strength and stiffness) and changes in their failure mechanisms. These degradations may lead to irreversible damage or sudden collapse of the related structures. From the predictive analysis stand point, accurate constitutive theories are required to simulate the variations of concrete mechanical failure behavior under high and durable temperature fields. In the realm of the smeared crack approach, non-local model strategies are required to objectively reproduce failure behaviors under coupled thermo-mechanical loading conditions, while realistic descriptions of the involved characteristic lengths are needed to objectively reproduce the variation from ductile to brittle failure modes depending on the acting confining pressure and temperature. In this work, a thermodynamically consistent gradient poroplastic model for concrete subjected to high temperatures is proposed. A particular and simple form of gradient-based poroplasticity is considered whereby the state variables are the only ones of non-local character. The degradations of these variables due to coupled thermo-mechanical effects are described in the framework of the thermodynamic approach. After describing the material formulation, numerical analyses are presented which demonstrate the predictive capabilities of the proposed constitutive theory for different stress paths and thermal conditions.Fil: Ripani, Marianela. Universidad de Buenos Aires. Facultad de Ingenieria. Departamento de Construcciones y Estructuras. Laboratorio de Materiales y Estructuras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Etse, Jose Guillermo. Universidad de Buenos Aires. Facultad de Ingenieria. Departamento de Construcciones y Estructuras. Laboratorio de Materiales y Estructuras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vrech, Sonia Mariel. Universidad de Buenos Aires. Facultad de Ingenieria. Laboratorio de Metodos Numericos En Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mroginski, Javier Luis. Universidad de Buenos Aires. Facultad de Ingenieria. Laboratorio de Metodos Numericos En Ingenieria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Micropropagation of grape rootstocks of interest for Misiones province

Con el objeto de micropropagar portainjertos de vid de interés para la provincia de Misiones (Paulsen 1103 y Vr 04343) se cultivaron segmentos nodales y ápices meristemáticos. Para el establecimiento de segmentos nodales se evaluaron diferentes concentraciones del medio propuesto por Murashige y Skoog (MS) -¼, ½, 1- adicionando diferentes concentraciones de benciladenina (0; 1; 3 y 5 mg.L-1) y ácido naftalenacético (0 y 0,01 mg.L-1). Se evaluaron estado fisiológico y topófisis de yemas. En fase de multiplicación se evaluaron ápices, segmentos uni y binodales con o sin hoja desplegada. Para el establecimiento de ápices se evaluó el medio MS ½ suplementado con bencilaminopurina (0; 0,5; 1; 2 mg.L-1). Los mejores resultados para el establecimiento de segmentos nodales se obtuvieron con yema despierta en medio MS ¼ sin adición de reguladores. La multiplicación de los mismos puede realizarse partiendo de un explanto uni o binodal con o sin hoja. Al utilizar ápices como explanto, se debe adicionar al medio MS ½ bencilaminopurina en una concentración de 0,5 mg.L-1. En la aclimatación de las plantas, se obtuvieron valores de supervivencia de 80 a 90%.In order to develop a micropropagation system for different grape rootstock of interest for Misiones Province (Paulsen 1103 and Vr 04343), nodal segments and root tips were culturated. Different concentrations of the medium proposed by Murashige and Skoog (MS) -¼, ½ , 1- adding different concentrations of benzyladenine (0; 1; 3 and 5 mg.L-1) and naphthylacetic acid (0 and 0.01 mg.L-1) were evaluated for the establishment of nodal segments. Topofisis and physiological state of the buds were also evaluated. Shoot tips and one-node and twonode segments with or without leave were evaluated in the multiplication stage. For the establishment of shoot tips the medium MS ½ supplemented with benzylaminopurine (0; 0.5; 1; 2 mg.L-1) was evaluated. The best results for establishment phase of nodal segments with the bud were obtained with the medium MS ¼ without regulator’s addition. Multiplication phase can start from an one or two-node explant with or without leaf. When using shoot tips as explant, the medium MS ½ should be added with benzyladenine at 0.5 mg.L-1. In acclimated plants, we obtained survival values between 80 and 90%.Fil: Guerrero, Diego R.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Mroginski, Luis A.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Krivenky, Mario A.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro AzulFil: Domínguez, Martín C.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro Azu

Plant regeneration of tea (Camellia sinensis) by in vitro culture of meristems, axillary buds and uninodal segments

Tres tipos de explantes de dos clones ( C H 1 4 I N TA y C H 3 1 8 I N TA ) d e t é (Camellia sinensis (L.) O. Kuntze) fueron evaluados para su regeneración in vitro, bajo la influencia de dos citocininas (BAP y CIN) y una giberelina (AG3). Previa desinfección, con etanol 70% (1 minuto) e hipoclorito de sodio 1,5% (20 minutos) y tres enjuagues con agua destilada estéril, los explantes fueron aislados y cultivados en los distintos medios de cultivo. Las mejores respuestas en formación de vástagos se registraron con los segmentos uninodales de ambos clones cultivados en el medio ½ MS + 1 mg/L de BAP o con el cultivo de yemas axilares del clon CH 14 INTA en el medio ½ MS + 1 mg/L de BAP o del clon CH 318 INTA en el medio ½ MS + 1 mg/L BAP + 1 mg/L AG3. Los mejores resultados con el empleo de meristemas caulinares se obtuvieron en el medio ½ MS + 1 mg/L de CIN y 1 mg/L de AG3. Los vástagos obtenidos fueron enraizados mediante su cultivo en ¼ MS + 6 mg/L de IBA.Plants of two clones (CH 14 INTA and CH 318 INTA) of tea (Camellia sinensis (L.) O. Kuntze) were regenerated by in vitro culture of three types of explants disinfected by immersion in 70% ethanol (1 min) and 1.5% sodium hypochlorite (20 min). The best medium for shoot regeneration from uninodal segments, for both clones, as well as for axillary buds of CH 14 INTA clone was ½ MS + 1 mg/L BAP. While the best medium for axillary buds of CH 318 clone was ½ MS + 1 mg/L BAP + 1 mg/L AG3. For meristems culture, the best medium, for both clones was ½ MS + 1 mg/L KIN + 1 mg/L AG3. Rooting of regenerated shoots were achieved by culture them on ¼ MS + 6 mg/L IBA.Fil: Molina, Sandra P.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Cerro AzulFil: Pérez, María Laura. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Rey, Hebe Y.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Mroginski, Luis A.. Universidad Nacional del Nordeste. Facultad de Ciencias Agraria