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Search Results: 1 - 10 of 337953 matches for " Manuel Sánchez-Olate "
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Proteomic Analysis through Adventitious Rooting of Pinus radiata Stem Cuttings with Different Rooting Capabilities  [PDF]
Carolina álvarez, Luis Valledor, Patricia Sáez, Manuel Sánchez-Olate, Darcy Ríos
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.714174
Abstract: In forest production systems, vegetative propagation of elite clones through adventitious rooting is a common practice. In Chile, adventitious rooting is the main methodology for vegetative reproduction of Pinus radiata. However, the capability of produce adventitious roots in gymnosperms decreases with aging. While it is true that some efforts have been made to identify markers or/and regulators of the aging process and adventitious rooting, molecular mechanisms that regulate both processes are scarcely known, especially at protein level. This research evaluated qualitative and quantitative changes in protein accumulation during the adventitious rooting process of P. radiata stem cuttings, with different rooting capabilities. Beside, an analysis of morpho-anatomical changes was performed in stem cuttings with high and low rooting capabilities, during the adventitious rooting process. It was observed that juvenile 1-year-old stem cuttings rooted in a 100%, while aged stem cuttings (3-year-old) presented only a 20% of rooting. According to the results of differential protein accumulation, univariate and multivariate analysis indicated that in total, 114 and 89 proteins were differentially accumulated in juvenile and aged cuttings, respectively. Also, identification of such proteins showed the presence of proteins related to cell wall organization and the presence of a protein related with proper distribution of auxin PIN transporter, both key in the new meristem formation process during adventitious rooting.
Effect of Photon Flux Density and Exogenous Sucrose on the Photosynthetic Performance during In Vitro Culture of Castanea sativa  [PDF]
Patricia L. Sáez, León A. Bravo, Manuel Sánchez-Olate, Paulina B. Bravo, Darcy G. Ríos
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.714187
Abstract: The low photon flux density (PFD) under in vitro conditions and sucrose added to the culture medium negatively limits the photochemical activity and photoprotective mechanisms of microshoots. In this work we hypothesize that decreasing sucrose in the culture medium in combination with increasing irradiance, could improve the photosynthesis and consequently the in vitro growth. We evaluated the effect of exogenous sucrose (30 and 5 g·L-1, HS and LS, respectively), under different PFD (50 and 150 μmol photons m-2·s-1, LL and HL, respectively) on the photosynthetic performance and growth of Castanea sativa microshoots. Decreasing sucrose negatively affected the physiological attributes evaluated. Only chloroplast ultrastructure was improved by LS; however this did not lead to an improved in photosynthesis or growth. HL HS produced an increase in photosynthetic activity and chlorophyll contents, reaching under these conditions a higher proliferation rate and biomass production. Additionally, the photochemical activity (electron transport rate and non-photochemical quenching) was improved by HL. Thus, our results suggest that, at least for C. sativa HL is beneficial during the in vitro culture, improving photosynthetic performance as well as growth, but this is only possible in the presence of moderate concentrations of sucrose added to the culture medium.
Changes in Gene Expression in Needles and Stems of Pinus radiata Rootstock Plants of Different Ontogenic Age  [PDF]
Carolina Alvarez, Luis Valledor, Patricia Sáez, Rodrigo Hasbún, Manuel Sánchez-Olate, María Jesús Ca?al, Darcy Ríos
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.78116
Abstract: A major problem in forest clonal productivity is the loss of morphogenetic capability with the increasing age of plants. However, despite of the importance of loss of morphogenetic competence, very little research has been done about the underlying mechanisms involved in this process. For this reason, a gene expression analysis using dot blot technique was performed in needles and stems of 1- and 3-year old Pinus radiata rootstock plants with a proved decrease in morphogenetic competence. Needles of one year old rootstock plants showed a higher number of up-regulated in genes mainly corresponding to photosynthesis and protein synthesis, degradation and modification, reflecting a higher number of active pathways in younger hedges, contrary to the older ones. Gene expression profiles found in stems are in agreement with those found in needles, indicating more active pathways in younger rootstock plants than in older ones. Several transcripts regulating transcription and translation were up-regulated in young competent tissues. Three-year-old stems presented an increase in the expression of an ethylene response factor, involved in plant organ senescence, indicating that pathways involved in senescence and ageing might inhibit the adventitious root formation, as in the older cuttings.
Photochemical Efficiency during the Establishment and Consolidation Phases of in Vitro Pinus radiata Micrograft Made from Scions of Different Ontogenetic Age  [PDF]
María E. Materán, Patricia L. Sáez, Manuel Sánchez-Olate, León A. Bravo, Roberto Rodríguez, Darcy Ríos, Rafael E. Coopman
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.61026
Abstract: The aim of the present study was to evaluate the applicability of maximal photochemical efficiency of photosystem II (Fv/Fm) as an early estimate of P. radiata micrografts viability coming from different position (basal vs. apical) in the ortets. We hypothesize that Fv/Fm variation is a good indicator of micrograft’s viability and phenological stage during micrograft development. The micrografts were established in QL medium supplemented whit 0.1 mg·L-1 IBA and 1 mg·L-1 BAP and cultured at 25°C ± 2°C and 80 μmol photons m-2s-1 of photosynthetic active radiation by 16 h per day. During the establishment and consolidation phase, we found significant differences in Fv/Fm with respect to time and buds positions provenience. During establishment, basal shoot tips have lower Fv/Fm than apical shoot tips, which agrees with the lowest viability (35%). However, during the consolidation phase, the trend changed and basal shoot tips presented higher Fv/Fm than apical shoot tips and showed an increase in ETR and NPQ, with respect to apical shoots and ortet. Although the measurement of fluorescence parameters implies the insertion of the fluorometer sonde in vitro, this implies aseptic considerations, but always conveies a contamination risk. We conclude that fluorescence (Fv/Fm, ETR, NPQ) can be indicators of the micrograft’s development according to the shoot tips position in the ortet and can be useful early-indicators of the scions’ physiological condition during micrograft transition from establishment to consolidation.
Multiplicación in vitro de Eucalyptus globulus mediante sistema de inmersión temporal
González,Ricardo; Ríos,Darcy; Avilés,Fabiola; Sánchez-Olate,Manuel;
Bosque (Valdivia) , 2011, DOI: 10.4067/S0717-92002011000200005
Abstract: with the object of establishing mass production methods of eucalyptus globulus, factors affecting its in vitro multiplication stage by temporary immersion were studied. for this, five microshoots per flask containing 250 ml of murashige and skoog medium were disposed. factors such as immersion frequency (6, 12, 24, 48 h), immersion time (1, 2 and 3 min) and macronutrients concentration (25, 50 and 100 %) were studied. in a second stage, the addition into medium of 6-bencylaminopurine (0, 2.2 and 4.4 μm), polyvinylpyrrolidone (0, 250 y 500 mg l-1) and sucrose concentration (43.8 and 87.6 mm) was analyzed. a completely random design with factorial arrangement was used in each stage. variables evaluated were number of new shoots per flask, dry and fresh weight rate and final ph of culture medium. the best rate of multiplication and less hyperhydration was obtained with immersion time of 2 min, a frequency of 12hours, macronutrients at 50 %, 2.2 μmol of 6-bencylaminopurine, 43.8 mm of sucrose and 250 mg l-1 of polyvinylpyrrolidone. time and frequency of immersion interaction affects multiplication rate and microshoot hyperhydration. use of 6-bencylaminopurine (2,2 μm) and polyvinylpyrrolidone (250 mg l-1) increases multiplication rate without influence on microshoot hyperhydration. a reduction on sucrose concentration decreases hyperhydration without affecting formation of new shoots.
Comparison of Root Induction in Mature Filbert (Corylus avellana L.) Explants by Agrobacterium Rhizogenes and Indolbutiric Acid
Sánchez-Olate,Manuel; Sáez,Patricia; Cartes,Priscila; Alvarez,Carolina; Ríos,Darcy;
Chilean journal of agricultural research , 2009, DOI: 10.4067/S0718-58392009000100013
Abstract: from in vitro cultured adult material of corylus avellana l. cv. negretta, adventitious rooting of microshoots was evaluated. rhizogenic induction mediated by two strains of wild-type agrobacterium rhizogenes (a477 and a478) and indolbutyric acid (iba) were compared under two light conditions (16:8 h photoperiod and complete darkness). the results indicate that in the 16:8 h photoperiod induction, the rooting rate with iba (90%) was significantly higher than that obtained with the strain a477 of a. rhizogenes (67.7%), while with the strain a478 no statistically significant difference was obtained for the same variable (75%). on the other hand, under complete darkness, rooting mediated by iba (90%) significantly surpassed the results obtained with both strains of a. rhizogenes (40 and 20%, for a478 and a477, respectively). in terms of the morphological variables of the resulting root system, induction mediated by iba, with a 16:8 h photoperiod, generates a significantly higher number of roots (19 roots per microshoot) than that obtained with a. rhizogenes (mean 3.7 roots per microshoot), producing significant differences when comparing the results with the strain a478 (5 roots per microshoot) to those of the strain a477 (2.4 roots per microshoot). induction under complete darkness does not have any effect on root number, independent of the rhizogenic inductor employed. root length did not present significant differences among treatments, except in the presence of a. rhizogenes a477 and darkness.
Effect of Culture Medium in Callogenesis from Adult Walnut Leaves (Juglans regia L.)
Avilés,Fabiola; Ríos,Darcy; González,Ricardo; Sánchez-Olate,Manuel;
Chilean journal of agricultural research , 2009, DOI: 10.4067/S0718-58392009000300020
Abstract: to define preliminary aspects of walnut (juglans regia l.) callogenesis in indirect propagation systems, this work analyzed callogenic induction in adult leaves of walnut in broadleaf trees (btm), murashige and skoog (ms) driver kuniyuki walnut (dkw) and woody plant (wpm) media. leaf segments of 1 cm2, previously sterilized, were placed in each culture medium, supplemented with 21.4 μm naphtalene acetic acid (naa) and 8.8 μm 6-benzylaminopurine (bap). a completely random design was used; the experimental unit was a petri dish with six callus explants. each treatment was composed of seven petri dishes. callogenesis (%), nodular calli (%) and histology of calli explants were evaluated at 4 weeks by staining 10 μm slices with safranine-fastgreen. there were no significant differences (α = 0.05) in callogenesis among evaluated media; but nodular calli percentages were significantly higher in btm (75%) and wpm (63%). only in calli obtained in the btm medium did the histology show the presence of meristematic zones, but without external expression. these results indicate that the medium influences the morphogenic characteristics of resultant callus. calli produced in btm presented better morphogenic potential, with meristems at primary stages of organization.
Rhizogenic Induction in Adult Juglans regia L. cv. Serr Tissue Induced by Indole Butyric Acid and Agrobacterium rhizogenes
Sánchez-Olate,Manuel; Sáez,Patricia; Ríos,Darcy;
Chilean journal of agricultural research , 2009, DOI: 10.4067/S0718-58392009000200019
Abstract: the in vitro introduction of adult walnut (juglans regia l.) tissue represents an opportunity to clone elite genotypes whose selection occurs in advanced ontogenic states. with the purpose of developing a protocol to allow mass propagation of valuable genotypes from adult material, a comparison was made between two root induction systems of walnut microshoots of the fourth subculture of adult walnut tissue of an in vitro introduction program previously reinvigorated through traditional grafting. rhizogenic induction by indole-3-butyric acid (iba) and agrobacterium rhizogenes was used. the rhizogenic process was analyzed in two phases for both auxinic (t1: 3 mg l-1 iba; t2: 5 mg l-1 iba) and a. rhizogenes inductions (t3: a-477; t4: a-478). the first phase of root induction was during 3 days in the dark while the second phase, root manifestation, was 27 days. rooting percentage was evaluated and the induced root systems characterized (number, length, diameter, and root insertion zone) in all the procedures. the best rooting results were obtained in t2, although the response obtained with a. rhizogenes didn?t differ from the t1 response. this appears to be an increasingly interesting methodology for adventitious rhizogenesis in this species.
Variación de la Tasa de Enraizamiento Asociada al Número de Subcultivo y Diámetro de Microtallos de Casta o Castanea sativa Mill Rooting Rate Variation Related to Subculture Number and Diameter of Chestnut Castanea sativa Mill. Microshoots
Darcy Ríos L,Fabiola Avilés M,Manuel Sánchez-Olate,René Escobar R
Agricultura Técnica , 2005,
Abstract: Este estudio tuvo por objeto determinar el número de subcultivo y el diámetro basal en el cual se obtiene la mayor tasa de enraizamiento ex vitro para microtallos de casta o, Castanea sativa Mill., obtenidos vía cultivo in vitro. El material vegetal correspondió a microtallos provenientes del cultivo de embriones con entre 7 y 12 subcultivos durante la etapa de proliferación, para la cual se utilizó medio Driver y Kuniyuki Walnut (DKW) con los macronutrientes reducidos a la mitad y suplementado con 1 mg L-1 6-benzilaminopurina (BAP) y 0,1 mg L-1 de ácido indol 3-butírico (AIB). Se utilizó el método de inducción rápida de enraizamiento sumergiendo los tallos en una solución de 0,5 mg mL-1 de AIB durante 15 min. Para la etapa de enraizamiento, se utilizó como sustrato corteza de pino:perlita (4:1, v/v) evaluando los resultados a los 20 días de cultivo. Las variables evaluadas fueron tasa de supervivencia (%), tasa de enraizamiento (%), número de raíces, largo de raíces (mm), presencia de callo y aspecto del sistema radicular. Los resultados mostraron una disminución de la capacidad de enraizamiento a medida que aumenta el número de subcultivo. El factor diámetro de microtallo no presentó diferencias significativas respecto a las variables evaluadas. This study had the objective of determining the subculture number and the shoot basal diameter that produces the best rooting rate ex vitro of chestnut, Castanea sativa Mill., microshoots obtained via in vitro culturing. The plant material corresponded to microcuttings obtained from embryo cultures with between 7 and 12 subcultures in the proliferative stage, for which Driver and Kuniyuki Walnut (DKW) medium was used with the macronutrients reduced to a half and supplemented with 1 mg L-1 6-benzylaminopurine (BAP) and 0.1 mg L-1 indole-3-butiric acid (IBA). The quick induction rooting method was used, submerging the base of the microcuttings in a solution of 0.5 mg mL-1 of IBA for 15 min. For the rooting stage, pine bark:perlite (4:1, v/v) substrate was used, carrying out the evaluation of results at 20 days after culturing. The evaluated variables were survival rate (%), rooting rate (%), root number, root length (mm), callus presence and visual aspect of the rooting system. The results showed a decrease of rooting capacity as the subculture number increases. The factor microcutting diameter did not present significant differences with respect to the evaluated variables.
Effect of Culture Medium in Callogenesis from Adult Walnut Leaves (Juglans regia L.) Efecto del Medio de Cultivo en la Callogénesis de Nogal (Juglans regia L.) a Partir de Hojas Adultas
Fabiola Avilés,Darcy Ríos,Ricardo González,Manuel Sánchez-Olate
Chilean Journal of Agricultural Research , 2009,
Abstract: To define preliminary aspects of walnut (Juglans regia L.) callogenesis in indirect propagation systems, this work analyzed callogenic induction in adult leaves of walnut in broadleaf trees (BTM), Murashige and Skoog (MS) Driver Kuniyuki Walnut (DKW) and Woody Plant (WPM) media. Leaf segments of 1 cm2, previously sterilized, were placed in each culture medium, supplemented with 21.4 μM naphtalene acetic acid (NAA) and 8.8 μM 6-benzylaminopurine (BAP). A completely random design was used; the experimental unit was a Petri dish with six callus explants. Each treatment was composed of seven Petri dishes. Callogenesis (%), nodular calli (%) and histology of calli explants were evaluated at 4 weeks by staining 10 μm slices with safranine-fastgreen. There were no significant differences (α = 0.05) in callogenesis among evaluated media; but nodular calli percentages were significantly higher in BTM (75%) and WPM (63%). Only in calli obtained in the BTM medium did the histology show the presence of meristematic zones, but without external expression. These results indicate that the medium influences the morphogenic characteristics of resultant callus. Calli produced in BTM presented better morphogenic potential, with meristems at primary stages of organization. Con el objeto de definir aspectos preliminares de la callogénesis de nogal(Juglans regia L.), para establecer, sistemas de propagación vegetativa vía indirecta, este trabajo analizó la inducción callogénica en hojas adultas de nogal, utilizando los medios de cultivo broadleaves tree (BTM), Murashige y Skoog (MS), Driver Kuniyuki Walnut (DKW) y Woody Plant (WPM). Se utilizaron segmentos foliares de 1 cm2 previamente esterilizados fueron dispuestos en cada medio de cultivo suplementado con 21,4 μM de ácido naftalén acético (ANA) y 8,8 μM de 6-bencilaminopurina (BAP). Se utilizó un dise o completamente aleatorio, la unidad experimental correspondió a una placa Petri con seis segmentos foliares. Cada tratamiento estuvo compuesto por siete repeticiones. A las 4 semanas de cultivo se evaluó la callogénesis (%), callos nodulares (%), e histología de macizos callosos, para los que se obtuvieron cortes de 10 μm a los cuales se realizó tinción con safranina-fastgreen. No se registraron diferencias significativas en la inducción de callogénesis entre los medios evaluados (α = 0,05); pero el porcentaje de callos nodulares fue significativamente mayor en los medios BTM (75%) y WPM (63%). Sólo en el medio BTM, la histología mostró presencia de zonas meristemáticas en el interior del macizo, sin que se observara expres
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