Miriam Arena | UNIVERSIDAD DE MORON (original) (raw)

Papers by Miriam Arena

Scientia Horticulturae, 2014

In recent years there has been renewed interest in locally grown and underutilized wild species a... more In recent years there has been renewed interest in locally grown and underutilized wild species as sources of bioactive compounds. Barberry (Berberis microphylla G. Forst) is among the southernmost growing fruit bearing species worldwide. The aim of this study was to characterize this species. We evaluated the antioxidant capacity of ripe barberry fruits as compared to pear, orange, apple, strawberry and blueberry. In a second set of experiments ripe barberry fruit was harvested and treated with ethylene and 1-MCP and the changes in ethylene production and respiration rate during storage were assessed. Finally, ripe barberries were harvested and stored at 0, 5 or 10 • C for 0, 3, 7, 11 or 15 days. During this period we determined weight loss, respiration rate, the percentage of rotten and physiologically decayed berries, firmness, sugar content, acidity, pH, anthocyanins, phenolics and antiradical capacity. Barberries showed 10-fold higher antioxidant capacity than apple, orange and pear and superseded four times that of antioxidant-rich fruits such as blueberry. 1-MCP treatments increased ethylene production suggesting that the hormone auto inhibits it biosynthesis. The fruit stored best at 0 • C and this should be the recommended temperature to minimize deterioration and prevent losses of bio-active compounds. The fruits show a non-climacteric physiology, with ethylene biosynthesis being under negative feedback control. Barberries are an extraordinary high source of antioxidants among fruits.

Scientia Horticulturae, 2011

The aim of this work was to study the time course and pattern of fruit growth and the evolution o... more The aim of this work was to study the time course and pattern of fruit growth and the evolution of some of the chemical attributes such as soluble solids, acidity, and anthocyanin content in Ribes magellanicum plants growing in a natural environment near Ushuaia city, Tierra del Fuego (Argentina). Fruit growth and composition presented significant changes along the days from the full bloom phase. Fresh and dry fruit weight exhibited a typical double sigmoid curve. The first period of rapid fresh fruit growth was from full bloom phase until 28 days after, followed by a lag period until 42 days from the full bloom phase, and then by a second period of rapid increase until 56 days from the full bloom phase. Then, fresh fruit weight increased slowly (days 70-98 from the full bloom phase), reaching its maximum. Afterwards, fresh fruit weight decreased significantly until the end of the summer, and the fruiting period approximately ended 112 days from full bloom phase. On a dry weight basis the maximum fruit biomass was reached 98 days from the full bloom phase. Evolution of fruit growth was related with the compositional changes evaluated. By day 98 from the full bloom phase, soluble solids (17.5 • Brix) and anthocyanin content (240.1 mg/100 g fruit fresh weight) were at their maximum, while at this time the total titratable acidity was at a minimum (0.4%). The results obtained not only contribute to the knowledge of the quantitative content of anthocyanin, a metabolite with nutraceutical value, but also give some tools for the definition of the optimal harvest time of R. magellanicum fruits, which it is important for fruit destination.

Peroxidases play a major role in several physiological processes. Specifically, in vitro activity... more Peroxidases play a major role in several physiological processes. Specifically, in vitro activity of this enzyme was used as a marker to identify different rooting phases of Nothofagus. The study of peroxidase profile patterns during rhizogenesis in this genus could give additional information about this topic, to justify the use of peroxidase isoforms as a more specific biochemical marker than total peroxidase activity. This work gives information on qualitative and quantitative changes in isoperoxidase expression (basic and acidic peroxidases) during in vitro rooting of N. antarctica microshoots through native PAGE. Time course analysis of isoperoxidase activity during rhizogenesis allowed positive correlation with specific morphogenic stages. Seventeen peroxidase bands were detected, 4 basic and 13 acidic. Four of the acidic peroxidases appeared during the induction stage of rooting. Variation in the number and relative activity of the isoperoxidases was found during different stages of adventitious rooting. The variation in the number and activity of isoperoxidases provides a good indicator of the processes involved in adventitious rooting of N. antarctica. Possible linkage of basic isoperoxidases with auxin metabolism and the role of certain isoperoxidases in specific rooting processes are also discussed.

New Zealand Journal of Botany, 2012

The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxi... more The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxifolia and their correlations were studied to determine the optimal time and conditions needed to obtain maximum phenolic content. Anthocyanin content increased from 1.7 to a maximum of 752.7 mg ×100 g (1 FW at the end of ripening, while the flavonoid content was maximal in unripe fruits [604.0 mg (')-catechin equivalents ×100 g (1 FW]. Total phenolic compounds decreased from 968.1 to a minimum of 746.3 mg gallic acid equivalents ×100 g (1 FW just as soluble solids started to accumulate; a maximum of 1522.9 mg gallic acid equivalents ×100 g (1 FW was attained at the end of ripening. Both variables (1,1-diphenyl-2-picrylhydrazyl scavenging effect and reducing power) were maximum in unripe fruits, and decreased during the ripening period, although the 1,1-diphenyl-2-picrylhydrazyl scavenging effect increased again towards the end of this period. The accumulation patterns of phenols varied depending on the specific group of compounds considered, and could be correlated with fruit quality.

New Zealand Journal of Crop and Horticultural Science, 2007

Ribes magellanicum is a Patagonian deciduous shrub, with globose berries, purple at maturity, whi... more Ribes magellanicum is a Patagonian deciduous shrub, with globose berries, purple at maturity, which can be eaten fresh or used in marmalades and syrups. the aim of this work was to study the shoot growth and fruiting of R. magellanicum in plants growing naturally near Ushuaia city, Tierra del Fuego, Argentina, as a first step towards its later domestication. shoot growth was significantly higher in the northern exposures compared with the southern exposures, as well as in the upper half of the plants in comparison with the lower ones. Fruit production per shoot was significantly higher in 2004 compared with 2003. North-west and south-west exposures favored fruit production, whereas the best values were found in the upper half of the plants and in long shoots compared to the lower half of the plants and the short shoots, respectively. R. magellanicum plants growing naturally near ushuaia city, formed c. 900 shoots per plant at the end of the growing season in 2003, whereas nearly 500 fruiting shoots with 595 racemes and 3000 fruits with a weight of 331 g were formed. Sixty-five percent of the fruiting shoots were in the upper half of the plants. these results are the first antecedents on growth and fruiting of R. magellanicum in Austral Patagonia and are relevant for its later domestication.

Summary. Peroxidases play a major role in several physiological processes. Specifically, in vitro... more Summary. Peroxidases play a major role in several physiological processes. Specifically, in vitro activity of this enzyme was used as a marker to identify different rooting phases of Nothofagus. The study of peroxidase profile pat- terns during rhizogenesis in this genus could give additional information about this topic, to justify the use of peroxidase isoforms as a more specific biochemical

New Forests, 2003

In vitro rooting constitutes a difficult step during the micropropagation process of forest speci... more In vitro rooting constitutes a difficult step during the micropropagation process of forest species. The successive media culture technique represents one way to overcome this barrier and includes modifying physical (e.g. photoperiod) and chemical (e.g. flavonoids) factors during the rooting phases. The aim of this study was to obtain a successive media protocol based on the incorporation of flavonoids during

New Zealand Journal of Botany, 2005

In vitro rooting protocols were previously performed on Nothofagus nervosa to optimise the cultur... more In vitro rooting protocols were previously performed on Nothofagus nervosa to optimise the culture medium and environmental conditions. A qualitative and quantitative tissue differentiation study during adventitious rooting in N. nervosa under different light/dark conditions was carried out to increase knowledge of the rhizogenesis process in shoots. The histological events through the rooting period were consistent with the proposed biochemical

New Zealand Journal of Botany, 1994

Pernettya mucronata (Ericaceae) is a Fuegian species from Argentina. The present work was carried... more Pernettya mucronata (Ericaceae) is a Fuegian species from Argentina. The present work was carried out to study the effects of increasing stratification times as well as the effects of light and dark on germination. The percentage germination at 60 days was significantly higher in the light (45.6%) than in the dark (29.4%). The percentage germination at 60 days was also

Scientia Horticulturae, 1995

A simple micropropagation system was developed for Ribes magellanicum. Significant differences be... more A simple micropropagation system was developed for Ribes magellanicum. Significant differences between strength of Murashige and Skoog medium macronutrient salts and 6-benzylaminepurine (BA) levels were observed on total number of new axillary shoots, shoot length and total number of leaves. After 3 weeks in culture, a maximum of four new axillary shoots per original explant were obtained in medium which

New Zealand Journal of Botany, 2005

Although Berberis buxifolia has been reported to propagate in vitro, rooting is difficult to achi... more Although Berberis buxifolia has been reported to propagate in vitro, rooting is difficult to achieve during subcultures, with reduced quantity and quality of roots, as is the case with many other woody species. Several cofactors of rhizogenesis have been proposed, and the role of polyamines in rooting has recently acquired relevance. Polyamines can stimulate or inhibit microshoot rooting depending on

New Zealand Journal of Botany, 2003

Berberis buxifolia is a Patagonian shrub with great economic potential for tinctorial, pharmacolo... more Berberis buxifolia is a Patagonian shrub with great economic potential for tinctorial, pharmacological, and food industries. Clonal propagation is possible through in vitro culture and is also useful for metabolite production. However, this species is difficult to root, and to improve this, more knowledge of rhizogenesis processes is needed. Polyamines and peroxidases are useful biochemical markers during analysis of rooting

Forest Ecology and Management, 2007

Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This... more Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This creates a seedling bank with a potential advantage in reestablishing canopy disturbances. To manage primary forests more effectively, it is important to understand the basis of plant regeneration ecophysiology, and their plasticity to changes in environmental factors. The objective was to evaluate the photosynthetic

Scientia Horticulturae, 2008

Scientia Horticulturae, 1997

Several factors were studied on adventitious shoot induction from leaf explants of Ribes mugellan... more Several factors were studied on adventitious shoot induction from leaf explants of Ribes mugellanicum cultured in vitro: type of explant, position of the leaves along the stem and growth regulators. Explants with petiole and complete leaf lamina presented the highest percentage of organogenesis. The position of the leaf along the shoot strongly affected the induction capacity. The percentage of explants with adventitious shoots was maximum (53%) when using apical leaves, with an average of three shoots per explant. 6-benzylaminopurine (BA) and N-benzyl-9-(2-tetrahydropyranyl)-adenine (BPA) had a significantly higher promotive effect than 6-(T-T-dimethylallylamino) purine (2iP) or kinetin on induction of adventitious shoots. Cytokinin concentration significantly affected shoot production, best responses being obtained with 4.44 to 8.88 PM. No significant differences were observed between cr-naphthaleneacetic acid (NAA) concentrations but 0.5 PM NAA usually promoted the highest number of non-vitrified shoots per explant. The results of this work show that R. magellanicum can be induced to form adventitious shoots from leaf explants cultured in vitro. 0 1997 Elsevier Science B.V.

New Zealand Journal of Crop and Horticultural Science, 2005

Rubus geoides, a native herb of Patagonia, has fruit with a bitter-sweet taste that can be eaten ... more Rubus geoides, a native herb of Patagonia, has fruit with a bitter-sweet taste that can be eaten fresh or in marmalades and jams. The aim of this work was to develop a protocol for the in vitro propagation of R. geoides. The proposed protocol allowed a multiplication rate of 1:3.5 to be obtained at day 63 with Murashige & Skoog (MS) medium with 1.10 µM 6-benzylaminopurine added. Most (80%) of the shoots rooted on MS with half-strength macronutrient salts and 2.46 µM indol-3-butyric acid added and an initial period of darkness of 7 days. The root systems were of suitable quality to begin the acclimatisation stage. These results are the first for R. geoides from adult plants obtained in the field.

New Zealand Journal of Botany, 2005

... GUILLERMO MARTÍNEZ PASTUR MIRIAM ARENA Centro Austral de Investigaciones Científicas (CONICET... more ... GUILLERMO MARTÍNEZ PASTUR MIRIAM ARENA Centro Austral de Investigaciones Científicas (CONICET) cc 92 (9410) Ushuaia, Tierra del Fuego, Argentina LUIS HERNANDEZ Departamento de Agronomía Universidad Nacional del Sur Altos del Palihue (8000) Bahía ...

New Zealand Journal of Botany, 2012

The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxi... more The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxifolia and their correlations were studied to determine the optimal time and conditions needed to obtain maximum phenolic content. Anthocyanin content increased from 1.7 to a maximum of 752.7 mg ×100 g (1 FW at the end of ripening, while the flavonoid content was maximal in unripe fruits [604.0 mg (')-catechin equivalents ×100 g (1 FW]. Total phenolic compounds decreased from 968.1 to a minimum of 746.3 mg gallic acid equivalents ×100 g (1 FW just as soluble solids started to accumulate; a maximum of 1522.9 mg gallic acid equivalents ×100 g (1 FW was attained at the end of ripening. Both variables (1,1-diphenyl-2-picrylhydrazyl scavenging effect and reducing power) were maximum in unripe fruits, and decreased during the ripening period, although the 1,1-diphenyl-2-picrylhydrazyl scavenging effect increased again towards the end of this period. The accumulation patterns of phenols varied depending on the specific group of compounds considered, and could be correlated with fruit quality.

New Forests, 2007

An in vitro rooting protocol for producing Nothofagus nervosa microplants using successive steps ... more An in vitro rooting protocol for producing Nothofagus nervosa microplants using successive steps during tissue culture is reported. Qualitative and quantitative changes in putrescine, spermidine, and spermine tissue contents, during the rooting process and their correlation with other biochemical markers and morphological changes, provided the rationale for their use during the study of a successive in vitro culture protocol for

Forest Ecology and Management, 2007

Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This... more Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This creates a seedling bank with a potential advantage in reestablishing canopy disturbances. To manage primary forests more effectively, it is important to understand the basis of plant regeneration ecophysiology, and their plasticity to changes in environmental factors. The objective was to evaluate the photosynthetic plasticity of Nothofagus pumilio seedlings to light intensity and soil moisture gradients; and to relate them with silvicultural prescriptions. Six treatments with three light intensities (4, 26 and 64% of the natural incident irradiance) and two soil moistures levels (40-60 and 80-100% soil capacity) were assayed under greenhouse controlled conditions. CO 2 gas exchanges were measured every month on seedlings growing in each condition. In the shaded treatments seedlings grow below their optimum photosynthetic potential (leaf light-saturated net photosynthesis rate of 5.1 mmol CO 2 m À2 s À1 ) compared with the lighted treatments by improving their photosynthetic performance (8.3-8.4 mmol CO 2 m À2 s À1 ). Seedling growing under low soil moisture conditions had higher leaf light-saturated net photosynthesis rate than plants grown under 80-100% soil water capacity (7.8 and 6.6 mmol CO 2 m À2 s À1 , respectively). When light (up to 150-200 mmol m À2 s À1 ) and soil moisture (40-60% soil capacity) levels were favourable, seedling plants could exhibit their maximum photosynthetic capacity. If one of these factors became limiting, the plants reduced their photosynthetic rate, e.g. N. pumilio seedlings with enough light and high levels of soil moisture, probably decreased their growth and fine roots activity. For this, application of silviculture systems must take into account the changes in both factors (light and soil moisture) for maximize the growth potential in the natural regeneration. These findings must be combined with morphological variables at a whole-plant, shoot, crown and leaf levels to determine the optimum growth conditions. #

Scientia Horticulturae, 2014

In recent years there has been renewed interest in locally grown and underutilized wild species a... more In recent years there has been renewed interest in locally grown and underutilized wild species as sources of bioactive compounds. Barberry (Berberis microphylla G. Forst) is among the southernmost growing fruit bearing species worldwide. The aim of this study was to characterize this species. We evaluated the antioxidant capacity of ripe barberry fruits as compared to pear, orange, apple, strawberry and blueberry. In a second set of experiments ripe barberry fruit was harvested and treated with ethylene and 1-MCP and the changes in ethylene production and respiration rate during storage were assessed. Finally, ripe barberries were harvested and stored at 0, 5 or 10 • C for 0, 3, 7, 11 or 15 days. During this period we determined weight loss, respiration rate, the percentage of rotten and physiologically decayed berries, firmness, sugar content, acidity, pH, anthocyanins, phenolics and antiradical capacity. Barberries showed 10-fold higher antioxidant capacity than apple, orange and pear and superseded four times that of antioxidant-rich fruits such as blueberry. 1-MCP treatments increased ethylene production suggesting that the hormone auto inhibits it biosynthesis. The fruit stored best at 0 • C and this should be the recommended temperature to minimize deterioration and prevent losses of bio-active compounds. The fruits show a non-climacteric physiology, with ethylene biosynthesis being under negative feedback control. Barberries are an extraordinary high source of antioxidants among fruits.

Scientia Horticulturae, 2011

The aim of this work was to study the time course and pattern of fruit growth and the evolution o... more The aim of this work was to study the time course and pattern of fruit growth and the evolution of some of the chemical attributes such as soluble solids, acidity, and anthocyanin content in Ribes magellanicum plants growing in a natural environment near Ushuaia city, Tierra del Fuego (Argentina). Fruit growth and composition presented significant changes along the days from the full bloom phase. Fresh and dry fruit weight exhibited a typical double sigmoid curve. The first period of rapid fresh fruit growth was from full bloom phase until 28 days after, followed by a lag period until 42 days from the full bloom phase, and then by a second period of rapid increase until 56 days from the full bloom phase. Then, fresh fruit weight increased slowly (days 70-98 from the full bloom phase), reaching its maximum. Afterwards, fresh fruit weight decreased significantly until the end of the summer, and the fruiting period approximately ended 112 days from full bloom phase. On a dry weight basis the maximum fruit biomass was reached 98 days from the full bloom phase. Evolution of fruit growth was related with the compositional changes evaluated. By day 98 from the full bloom phase, soluble solids (17.5 • Brix) and anthocyanin content (240.1 mg/100 g fruit fresh weight) were at their maximum, while at this time the total titratable acidity was at a minimum (0.4%). The results obtained not only contribute to the knowledge of the quantitative content of anthocyanin, a metabolite with nutraceutical value, but also give some tools for the definition of the optimal harvest time of R. magellanicum fruits, which it is important for fruit destination.

Peroxidases play a major role in several physiological processes. Specifically, in vitro activity... more Peroxidases play a major role in several physiological processes. Specifically, in vitro activity of this enzyme was used as a marker to identify different rooting phases of Nothofagus. The study of peroxidase profile patterns during rhizogenesis in this genus could give additional information about this topic, to justify the use of peroxidase isoforms as a more specific biochemical marker than total peroxidase activity. This work gives information on qualitative and quantitative changes in isoperoxidase expression (basic and acidic peroxidases) during in vitro rooting of N. antarctica microshoots through native PAGE. Time course analysis of isoperoxidase activity during rhizogenesis allowed positive correlation with specific morphogenic stages. Seventeen peroxidase bands were detected, 4 basic and 13 acidic. Four of the acidic peroxidases appeared during the induction stage of rooting. Variation in the number and relative activity of the isoperoxidases was found during different stages of adventitious rooting. The variation in the number and activity of isoperoxidases provides a good indicator of the processes involved in adventitious rooting of N. antarctica. Possible linkage of basic isoperoxidases with auxin metabolism and the role of certain isoperoxidases in specific rooting processes are also discussed.

New Zealand Journal of Botany, 2012

The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxi... more The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxifolia and their correlations were studied to determine the optimal time and conditions needed to obtain maximum phenolic content. Anthocyanin content increased from 1.7 to a maximum of 752.7 mg ×100 g (1 FW at the end of ripening, while the flavonoid content was maximal in unripe fruits [604.0 mg (')-catechin equivalents ×100 g (1 FW]. Total phenolic compounds decreased from 968.1 to a minimum of 746.3 mg gallic acid equivalents ×100 g (1 FW just as soluble solids started to accumulate; a maximum of 1522.9 mg gallic acid equivalents ×100 g (1 FW was attained at the end of ripening. Both variables (1,1-diphenyl-2-picrylhydrazyl scavenging effect and reducing power) were maximum in unripe fruits, and decreased during the ripening period, although the 1,1-diphenyl-2-picrylhydrazyl scavenging effect increased again towards the end of this period. The accumulation patterns of phenols varied depending on the specific group of compounds considered, and could be correlated with fruit quality.

New Zealand Journal of Crop and Horticultural Science, 2007

Ribes magellanicum is a Patagonian deciduous shrub, with globose berries, purple at maturity, whi... more Ribes magellanicum is a Patagonian deciduous shrub, with globose berries, purple at maturity, which can be eaten fresh or used in marmalades and syrups. the aim of this work was to study the shoot growth and fruiting of R. magellanicum in plants growing naturally near Ushuaia city, Tierra del Fuego, Argentina, as a first step towards its later domestication. shoot growth was significantly higher in the northern exposures compared with the southern exposures, as well as in the upper half of the plants in comparison with the lower ones. Fruit production per shoot was significantly higher in 2004 compared with 2003. North-west and south-west exposures favored fruit production, whereas the best values were found in the upper half of the plants and in long shoots compared to the lower half of the plants and the short shoots, respectively. R. magellanicum plants growing naturally near ushuaia city, formed c. 900 shoots per plant at the end of the growing season in 2003, whereas nearly 500 fruiting shoots with 595 racemes and 3000 fruits with a weight of 331 g were formed. Sixty-five percent of the fruiting shoots were in the upper half of the plants. these results are the first antecedents on growth and fruiting of R. magellanicum in Austral Patagonia and are relevant for its later domestication.

Summary. Peroxidases play a major role in several physiological processes. Specifically, in vitro... more Summary. Peroxidases play a major role in several physiological processes. Specifically, in vitro activity of this enzyme was used as a marker to identify different rooting phases of Nothofagus. The study of peroxidase profile pat- terns during rhizogenesis in this genus could give additional information about this topic, to justify the use of peroxidase isoforms as a more specific biochemical

New Forests, 2003

In vitro rooting constitutes a difficult step during the micropropagation process of forest speci... more In vitro rooting constitutes a difficult step during the micropropagation process of forest species. The successive media culture technique represents one way to overcome this barrier and includes modifying physical (e.g. photoperiod) and chemical (e.g. flavonoids) factors during the rooting phases. The aim of this study was to obtain a successive media protocol based on the incorporation of flavonoids during

New Zealand Journal of Botany, 2005

In vitro rooting protocols were previously performed on Nothofagus nervosa to optimise the cultur... more In vitro rooting protocols were previously performed on Nothofagus nervosa to optimise the culture medium and environmental conditions. A qualitative and quantitative tissue differentiation study during adventitious rooting in N. nervosa under different light/dark conditions was carried out to increase knowledge of the rhizogenesis process in shoots. The histological events through the rooting period were consistent with the proposed biochemical

New Zealand Journal of Botany, 1994

Pernettya mucronata (Ericaceae) is a Fuegian species from Argentina. The present work was carried... more Pernettya mucronata (Ericaceae) is a Fuegian species from Argentina. The present work was carried out to study the effects of increasing stratification times as well as the effects of light and dark on germination. The percentage germination at 60 days was significantly higher in the light (45.6%) than in the dark (29.4%). The percentage germination at 60 days was also

Scientia Horticulturae, 1995

A simple micropropagation system was developed for Ribes magellanicum. Significant differences be... more A simple micropropagation system was developed for Ribes magellanicum. Significant differences between strength of Murashige and Skoog medium macronutrient salts and 6-benzylaminepurine (BA) levels were observed on total number of new axillary shoots, shoot length and total number of leaves. After 3 weeks in culture, a maximum of four new axillary shoots per original explant were obtained in medium which

New Zealand Journal of Botany, 2005

Although Berberis buxifolia has been reported to propagate in vitro, rooting is difficult to achi... more Although Berberis buxifolia has been reported to propagate in vitro, rooting is difficult to achieve during subcultures, with reduced quantity and quality of roots, as is the case with many other woody species. Several cofactors of rhizogenesis have been proposed, and the role of polyamines in rooting has recently acquired relevance. Polyamines can stimulate or inhibit microshoot rooting depending on

New Zealand Journal of Botany, 2003

Berberis buxifolia is a Patagonian shrub with great economic potential for tinctorial, pharmacolo... more Berberis buxifolia is a Patagonian shrub with great economic potential for tinctorial, pharmacological, and food industries. Clonal propagation is possible through in vitro culture and is also useful for metabolite production. However, this species is difficult to root, and to improve this, more knowledge of rhizogenesis processes is needed. Polyamines and peroxidases are useful biochemical markers during analysis of rooting

Forest Ecology and Management, 2007

Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This... more Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This creates a seedling bank with a potential advantage in reestablishing canopy disturbances. To manage primary forests more effectively, it is important to understand the basis of plant regeneration ecophysiology, and their plasticity to changes in environmental factors. The objective was to evaluate the photosynthetic

Scientia Horticulturae, 2008

Scientia Horticulturae, 1997

Several factors were studied on adventitious shoot induction from leaf explants of Ribes mugellan... more Several factors were studied on adventitious shoot induction from leaf explants of Ribes mugellanicum cultured in vitro: type of explant, position of the leaves along the stem and growth regulators. Explants with petiole and complete leaf lamina presented the highest percentage of organogenesis. The position of the leaf along the shoot strongly affected the induction capacity. The percentage of explants with adventitious shoots was maximum (53%) when using apical leaves, with an average of three shoots per explant. 6-benzylaminopurine (BA) and N-benzyl-9-(2-tetrahydropyranyl)-adenine (BPA) had a significantly higher promotive effect than 6-(T-T-dimethylallylamino) purine (2iP) or kinetin on induction of adventitious shoots. Cytokinin concentration significantly affected shoot production, best responses being obtained with 4.44 to 8.88 PM. No significant differences were observed between cr-naphthaleneacetic acid (NAA) concentrations but 0.5 PM NAA usually promoted the highest number of non-vitrified shoots per explant. The results of this work show that R. magellanicum can be induced to form adventitious shoots from leaf explants cultured in vitro. 0 1997 Elsevier Science B.V.

New Zealand Journal of Crop and Horticultural Science, 2005

Rubus geoides, a native herb of Patagonia, has fruit with a bitter-sweet taste that can be eaten ... more Rubus geoides, a native herb of Patagonia, has fruit with a bitter-sweet taste that can be eaten fresh or in marmalades and jams. The aim of this work was to develop a protocol for the in vitro propagation of R. geoides. The proposed protocol allowed a multiplication rate of 1:3.5 to be obtained at day 63 with Murashige & Skoog (MS) medium with 1.10 µM 6-benzylaminopurine added. Most (80%) of the shoots rooted on MS with half-strength macronutrient salts and 2.46 µM indol-3-butyric acid added and an initial period of darkness of 7 days. The root systems were of suitable quality to begin the acclimatisation stage. These results are the first for R. geoides from adult plants obtained in the field.

New Zealand Journal of Botany, 2005

... GUILLERMO MARTÍNEZ PASTUR MIRIAM ARENA Centro Austral de Investigaciones Científicas (CONICET... more ... GUILLERMO MARTÍNEZ PASTUR MIRIAM ARENA Centro Austral de Investigaciones Científicas (CONICET) cc 92 (9410) Ushuaia, Tierra del Fuego, Argentina LUIS HERNANDEZ Departamento de Agronomía Universidad Nacional del Sur Altos del Palihue (8000) Bahía ...

New Zealand Journal of Botany, 2012

The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxi... more The accumulation patterns of phenolic compounds during fruit growth and ripening of Berberis buxifolia and their correlations were studied to determine the optimal time and conditions needed to obtain maximum phenolic content. Anthocyanin content increased from 1.7 to a maximum of 752.7 mg ×100 g (1 FW at the end of ripening, while the flavonoid content was maximal in unripe fruits [604.0 mg (')-catechin equivalents ×100 g (1 FW]. Total phenolic compounds decreased from 968.1 to a minimum of 746.3 mg gallic acid equivalents ×100 g (1 FW just as soluble solids started to accumulate; a maximum of 1522.9 mg gallic acid equivalents ×100 g (1 FW was attained at the end of ripening. Both variables (1,1-diphenyl-2-picrylhydrazyl scavenging effect and reducing power) were maximum in unripe fruits, and decreased during the ripening period, although the 1,1-diphenyl-2-picrylhydrazyl scavenging effect increased again towards the end of this period. The accumulation patterns of phenols varied depending on the specific group of compounds considered, and could be correlated with fruit quality.

New Forests, 2007

An in vitro rooting protocol for producing Nothofagus nervosa microplants using successive steps ... more An in vitro rooting protocol for producing Nothofagus nervosa microplants using successive steps during tissue culture is reported. Qualitative and quantitative changes in putrescine, spermidine, and spermine tissue contents, during the rooting process and their correlation with other biochemical markers and morphological changes, provided the rationale for their use during the study of a successive in vitro culture protocol for

Forest Ecology and Management, 2007

Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This... more Nothofagus seedlings often survive and grow slowly for a long time in the shaded understory. This creates a seedling bank with a potential advantage in reestablishing canopy disturbances. To manage primary forests more effectively, it is important to understand the basis of plant regeneration ecophysiology, and their plasticity to changes in environmental factors. The objective was to evaluate the photosynthetic plasticity of Nothofagus pumilio seedlings to light intensity and soil moisture gradients; and to relate them with silvicultural prescriptions. Six treatments with three light intensities (4, 26 and 64% of the natural incident irradiance) and two soil moistures levels (40-60 and 80-100% soil capacity) were assayed under greenhouse controlled conditions. CO 2 gas exchanges were measured every month on seedlings growing in each condition. In the shaded treatments seedlings grow below their optimum photosynthetic potential (leaf light-saturated net photosynthesis rate of 5.1 mmol CO 2 m À2 s À1 ) compared with the lighted treatments by improving their photosynthetic performance (8.3-8.4 mmol CO 2 m À2 s À1 ). Seedling growing under low soil moisture conditions had higher leaf light-saturated net photosynthesis rate than plants grown under 80-100% soil water capacity (7.8 and 6.6 mmol CO 2 m À2 s À1 , respectively). When light (up to 150-200 mmol m À2 s À1 ) and soil moisture (40-60% soil capacity) levels were favourable, seedling plants could exhibit their maximum photosynthetic capacity. If one of these factors became limiting, the plants reduced their photosynthetic rate, e.g. N. pumilio seedlings with enough light and high levels of soil moisture, probably decreased their growth and fine roots activity. For this, application of silviculture systems must take into account the changes in both factors (light and soil moisture) for maximize the growth potential in the natural regeneration. These findings must be combined with morphological variables at a whole-plant, shoot, crown and leaf levels to determine the optimum growth conditions. #