Seasonal Variation in Leaf Growth and Antioxidant Content of Moringa oleifera Cultivated at Buenos Aires, Argentina

The properties and applications of Moringa oleifera are so vast that it is called the "miracle tree". The objective of this work is to study the seasonal variations in the leaf antioxidant content and the scavenging activity on DPPH radicals in concordance with its growth on M. oleifera plants of two seed origin, Commercial (C, seeds that were obtained from a market) and Bolivia (B, seeds that were obtained from a commercial forest of Santa Cruz de la Sierra, Bolivia); the experiment was conducted at Buenos Aires, Argentina. Significant differences were found on leaf growth, antioxidant content and DPPH activity along the growing season. The lower leaf dry weight as percentage of fresh weight, higher specific leaf area, higher relative growth rate and lower phenol content on B leaves than C leaves could indicate that B plants are geared for a higher productivity rate of resource acquisition than C plants. Specific leaf area, leaf dry weight as percentage of fresh weight, phenol content and activity of DPPH radicals on leaf extracts were significantly correlated, which could be used on productivity estimation and nutraceutical valuation. The phenol content and activity of DPPH radicals of leaf extracts of B and C origins indicate that the leaves of the plants growing in the described conditions are of noteworthy value. These are the first antecedents for M. oleifera growing at Buenos Aires, Argentina, allowing to preliminary consider this area as one of the southernmost zone.Fil: Arena, Miriam Elisabet. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Radice, Silvia. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Berberis microphylla: A species with phenotypic plasticity in different climatic conditions

Berberis microphylla G. Forst., commonly called as "calafate" produces small fruits with high content of carbohydrates, phenols and antioxidants. The objective of this work was to characterize the vegetative and reproductive cycle of Berberis microphylla cultivated on Moreno (Buenos Aires province), Argentina in comparison with the results obtained in Ushuaia (Tierra del Fuego) which is its place of origin. Vegetative growth was very different in the two localities. Moreno plants grew with more lax branches than Ushuaia. In effect, length of the shoots was significantly higher for Moreno than Ushuaia plants. Flowering period in Ushuaia plants was concentrated in November while in Moreno it happens earlier and over a longer period. Pollen grains collected from Moreno flowers had a diameter of ~60 μm, significantly different to pollen grain from Ushuaia (57.11 μm). Nevertheless, pollen grain vitality was superior in Ushuaia flowers (75%) as compared to Moreno flowers (52%). On the other hand, fruit harvested in Moreno was at 60 days from full bloom while in Ushuaia plants at 120 days. Although the size and compounds measured in the fruits of Moreno were lower than those of Ushuaia, results obtained indicate that B. microphylla grown on Moreno is an interesting option to obtain another nutraceutical fruit near the centers of mass consumption.Fil: Radice, Silvia. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso, Marta. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; ArgentinaFil: Arena, Miriam Elisabet. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Environmental effect on the leaf morphology and anatomy of Berberis microphylla G. Forst

Berberis microphylla G. Forst is a fruit shrub native from Patagonia, considered as a non-timber forest product. In recent years, there has been an increased demand for its fruits, both for fresh and industrialized consumption, being the establishment of commercial orchards in different sites a need to meet this demand. B. microphylla cloned plants have been introduced from Ushuaia, Tierra del Fuego to Buenos Aires province in order to evaluate its phenotypic plasticity and the possibility of fruit production. At the same time, a comparative study on the morphology and anatomy of the mature leaves of B. microphylla grown in two different environmental conditions was carried out. Moreno leaves were significantly larger than Ushuaia leaves in all the morphological parameters registered, while Ushuaia leaves were more circular than Moreno leaves with the highest roundness and elongation indexes. Nevertheless, histological sections showed that Ushuaia leaves have one more layer of palisade cells respect to Moreno leaves. Ushuaia leaves showed higher palisade cells, larger abaxial epidermal cells and thicker cuticles than Moreno leaves. The stomatal density was superior on Moreno leaves. SEM of abaxial epidermis showed a surface with numerous ridges of different forms that prevent the layout of epidermal cells on Moreno leaves. Appearance of this surface is glossy and oily. On the contrary, epidermal cells are well recognized on Ushuaia leaves. Stomata of anomocytic type were observed and surface looks waxy. Auto-fluorescence on leaf cross sections were observed on the vascular bundles and partially on the epidermis cells. B. microphylla leaves showed a high phenotypic plasticity between the two sites of cultivation. The changes in the leaf morphology and structure observed in Moreno leaves could indicate that the plants are trying to adjust its morphology to the new culture conditions i.e. higher temperatures and lower irradiance.Fil: Radice, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Moron; ArgentinaFil: Arena, Miriam Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Characterization and evaluation of Berberis microphylla G. Forst pollen grains

Berberis microphylla, commonly known as “calafate”, is a non-timber forest product native from Patagonia, and its berries possess highlighted nutraceutical value. The objective of this research was to describe the morphology and anatomy of pollen grains of Berberis microphylla G. Forst genotypes growing spontaneously on the island of Tierra del Fuego (Argentina), and evaluate their vitality and germination. Pollen grain diameter varied from 40 to 47.26 µm, the pollen grains of 124 and 201 genotypes being significantly smaller than the others. Vitality measured by DAPI methodol-ogy was also variable among genotypes, although always about 50%. In vitro germination of pollen grains measured one day after the flowers were collected was very high for some genotypes (near 80%), and then decreased after 21 days of storage, except for genotype 123 whose germination value increased from 44.34 to 69%. The significant variability found in pollen performance (size, viability and germination) among B. microphylla genotypes from a natural population could be interpreted as an enhanced survival strategy to maximize reproduction fitness, with a marked capacity of response to environmental changes. High viable pollen frequency together with germination percentages observed in all the geno-types tested could indicate a good fertilization process. The correlation observed between size and germination percent-age could be used as markers of pollen grain performance, paving the way for possible B. microphylla breeding.Fil: Radice, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; ArgentinaFil: Arena, Miriam Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentin

Flower anatomy related to blooming development of Berberis microphylla G. Forst (Berberidaceae)

Berberis microphylla G. Forst. is a Patagonian native shrub commonly named “calafate”, which has a growing economic potential due to its dark blue berries that are consumed fresh, as jams and preserves, and are used for the production of soft drinks and ice cream. Moreover, the fruits have a high content of carbohydrates, phenols and antioxidants. The objective of this work was to show the changes observed in the flower from the emergence in relation to the floral phases and the importance that they have on pollination and fertilization. During the anthesis, the nectar is excreted inside and outside of the petal through the epidermis of the secretory tissue. The epidermis of the stigma is papillae with cells of greater length in the periphery of this structure simulating an additional ring. Secretory tissue is also present on the area of the fusion carpel. During anthesis, the epidermis glands of the stigma showed active secretion and these conditions favor pollen grain germination. Germinated pollen grains were observed after 12 hours of pollination and ten days later the pollen tube reached the ovule area. Pollen tube grew surrounded the ovules and probably some of them already accomplished the fertilization.Fil: Radice, Silvia. Universidad de Moron. Facultad de Agronomia y Ciencias Agroalimentarias. Laboratorio de Investigaciones En Fisiología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arena, Miriam Elisabet. Universidad de Moron. Facultad de Agronomia y Ciencias Agroalimentarias. Laboratorio de Investigaciones En Fisiología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Phenological growth and development stages of the native Patagonian fruit species Berberis buxifolia Lam

This work studied the phenological growth and development stages of Berberis buxifolia, a native Patagonian species, whose purple berries are of economic value. Data were recorded from a population of B. buxifolia adult plants, growing naturally near Ushuaia city, 54º 48´SL, 68º 19´WL (Tierra del Fuego, Argentina). The BBCH-scale has been adopted in this study, and the phenological stages were coded using two digits. Nine principal growth and development stages were recognized for the phenological description of B. buxifolia, starting with vegetative and mixed bud development (stage 0). The following four of them were assigned to the vegetative growth, which described leaf development on shoots (stage 1), shoot elongation (stage 3), development of plant propagation organs (stage 4) and partial senescence, beginning of dormancy (stage 9). The last four principal growth stages describe flower emergence (stage 5), flowering (stage 6), fruit development (stage 7) and maturity of fruit (stage 8).Fil: Arena, Miriam Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Giordani, Edgardo. Universita Degli Studi Di Firenze; ItaliaFil: Radice, Silvia. Universidad de Moron. Facultad de Agronomia y Ciencias Agroalimentarias. Laboratorio de Investigaciones En Fisiologia Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Flower development and pollen vitality of Moringa oleifera Lam. grown in a humid temperate climatic condition

Moringa oleifera is a tropical tree cultivated in many countries. This species has acquired a great importance in human nutrition and it was recently indicated as a “novel food” by the European Commission. Recently, moringa plants have been introduced in humid temperate climatic areas, among which Moreno (Buenos Aires Province - Argentina). In such area, the cultivation is possible for the production of leaves, but plants need protection during winter time in order to overcome damages due to low temperatures and hence to produce capsules and seeds. The main objective of this research was to study flower morphology and anatomy of M. oleifera, as well as microsporogenesis and viability of pollen grains of plants cultivated in Moreno in comparison with those produced in a humid sub-tropical climatic area of Argentina (San Miguel de Tucumán). Flowers grown in the temperate environment resulted similar for morphological parameters to those observed in the sub-tropical environment. Nevertheless, pollen grain fertility depended directly on air temperature and it was negatively affected by the lower temperatures registered in the temperate site. According to the observed results, pollen viability increases with mean monthly temperatures above 16°C

Guidelines for the Development of Herbal-Based Sunscreen

Sun protection is a complex topic, which involves various classes of compounds. The photoprotective effectiveness of a sunscreen involves many biological activities, such as ultraviolet (UV) radiation filter properties and antioxidant, anti-inflammatory, and antimutagenic effects. Formulation strategy is also a key factor. Several studies have examined the role of natural molecules as photoprotective compounds, and a considerable number of commercially available sunscreens contain herbal extracts but not as sunfilters. Indeed, the process of evaluation of UV-filtering and photoprotective activity of herbal compounds presents certain specific difficulties and needs in vitro and in vivo studies. Nowadays, no natural compound or vegetal extract has been approved by any country as official UV filter for sunscreen. With these premises, the aim of this chapter is to define a set of tests, which can help to evaluate the efficacy of an herbal extract in the field of sun protection; in other words, we propose a rational approach to the discovery of natural UV-filtering extract and molecules. The following electronic databases have been used as a source of information: SciFinder, PubMed, Google Scholar, ISI-Web of Science, and Scopus

Reuniones científicas

En Huerta Grande (Córdoba), del 30 de mayo a l2 de junio del corriente año, se realizó el 2° Simposio Argentino de Biotecnología Vegetal. A través de conferencias, mesas redondas y exposición de trabajos en paneles, los asistentes pudieron actualizar sus conocimientos sobre los proyectos que se están desarrollando en América latina y el Caribe. Durante los días 5 y 6 de julio de 1993 se realizó el 1° Encuentro de Anatomistas de la Madera de la Argentina en el Departamento de Tecnología e Industrialización de la Madera de la Facultad de Ciencias Agrarias y Forestales (UNLP), con la intención de integrar disciplinas y promover la asociación de áreas cuyas fronteras se superponen o complementan.Facultad de Ciencias Agrarias y Forestale

Histological changes of Berberis mikuna pollen grains in relation to viability and germinability

Berberis mikuna is a spontaneous shrub grown in the Tucuman-Bolivian subtropical jungle area and its fruits were highly prized as food by diaguitas and calchaquies who were local populations. Fruits are rich in phenolic compounds which would be responsible for the beneficial properties for health. Pollen preservation in gene banks should be implemented as standard procedures since pollen is a useful source of diverse alleles within a gene pool. Therefore, the aim of this work was to study the histological and ultrastructural changes of pollen grains after 45 days of conservation at different temperatures. Berberis mikuna pollen grain germination and viability decreased significantly after 45 days of its collection. Germination and viability decreased with increasing storage temperature, although the viability in T45 Ref and T45 Fr was similar. Ultrastructure studies revealed differences in the fibrillar structure of the intine, as well as the decrease in starch reserve in pollen grains stored at 5 °C andat room temperature.Fil: Radice, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Moron. Facultad de Agronomia y Ciencias Agroalimentarias. Laboratorio de Investigaciones En Fisiología Vegetal; ArgentinaFil: Galati, Beatriz Gloria. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica General; ArgentinaFil: Zarlavsky, Gabriela Elena. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica General; ArgentinaFil: Arena, Miriam Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Moron. Facultad de Agronomia y Ciencias Agroalimentarias. Laboratorio de Investigaciones En Fisiología Vegetal; Argentin