1,720,987 research outputs found
In vitro propagation of Cistus clusii Dunal, an endangered plant in Italy
Get PDFShoot tips and nodes from a genotype of Cistus clusii were cultured on a medium containing Murashige and Skoog macronutrients, Nitsch and Nitsch micronutrients, sucrose, iron, thiamine, myoinositol, and agar. This establishment medium, enriched with growth regulators and the biocide substances Plant Preservative Mixture and Thiabendazole lactate, improved explant survival by 14-16% and reduced contamination late in culture. For the proliferation stage, the explants rapidly formed axillary buds on a culture medium containing 6-benzylaminopurine (0.5 mg l-1). The best response for rooting was obtained on a culture medium with a 0.1 mg l-1indolebutyric acid supplement. Rooted plantlets were acclimatized to greenhouse conditions and then transferred to the field in order to evaluate their phenotypic homogeneity. Karyotyping showed that the in vitro propagated plantlets have the same chromosome numbers as the mother plants. The success of this work indicates that micropropagation can be a useful tool for the conservation of C. clusii Dunal, an endangered plant in Italy. © 2010 The Society for In Vitro Biology
Alfalfa (Medicago sativa L.) clones tolerant to salt stress: In vitro selection
No full textIn order to quickly and efficiently evaluate the salt tolerance of alfalfa, salinity tests were conducted on Medicago sativa L. var. australis, var. icon, var. loi, and var. gea, under in vitro conditions. Pregerminated seeds of four varieties were subjected to five different NaCl concentrations (0, 50, 100, 150, 200 mM). The influence of saline stress was estimated on the basis of survival percentage, growth parameters, and electrolyte leakage. The seedlings surviving on the medium enriched with salt at the highest concentration were presumed to be tolerant and represented the mother plants for the production of in vitro clones. In the following step, the clones were evaluated in vitro to confirm the salt tolerance. The influence of mild salt stress (75 mM NaCl) on the growth parameters of selected clones was examined. At the end of this trial, the proline accumulation and sodium content in alfalfa shoots were also quantified. The results suggest an increased level of proline promotes salt tolerance. Medicago sativa L. var. icon is highly tolerant in comparison with the other varieties tested. In vitro selection of M. sativa L. varieties on salt-containing media allowed us to obtain clones with increased salinity tolerance
The effect of mycorrhizal symbiosis on the development of micropropagated artichokes
Get PDFIn this work, microrosettes of Cynara cardunculus L. var. scolymus Fiori of the "catanese" type were subcultured in a medium supplemented with 6-benzylaminopurine (BAP) (0.05 mg l-1). For root induction, indoleacetic acid (IAA), α-naphthalene acetic acid (NAA) and indole-3-butyrric acid (IBA) were used at three concentrations: 2, 5 and 10 mg l-1. The highest percentage of rooted shoots was aided by the presence of 10 mg l-1IAA. Once transplanted in pots, the plantlets were inoculated with 10 g Glomus viscosum strain A6 (AM fungus). Acclimatisation was clearly facilitated by the addition of the AM fungus. Indeed, the mycorrhizal plantlets registered a survival of between 90 and 95% for the rooting shoots and 60% for the non-rooting shoots. The botanical characterization of the material produced was carried out in field and was based on several morphological and productive parameters. Data collected confirm the characteristics of the original cultivar, the efficiency of the in vitro propagation material and the possibility of using this technique in early types of artichoke. © 2005 Elsevier B.V. All rights reserved
Evaluation of commercial arbuscular mycorrhizal inoculants on micropropagated early globe artichoke during the acclimatization stage
No full textDuring the last years, mycorrhizal symbiosis has been used in many micropropagated horticultural crops in order to improve the acclimatization of in vitro plantlets. This root symbiosis, in facts, increases survival and growth rates of plants reducing the transplanting shock and biotic and abiotic stresses. Our previous results on micropropagated artichoke demonstrated the practice of mycorrhizal pure inoculum is effective in improving the quality of the artichoke micropropagated plantlets. The aim of this study was to test the efficacy of two commercial arbuscular mycorrhizal inoculants available in the market (Aegis - Glomus intraradices Italpolline and Symbivit® MYBATEC Ltd.) in promoting mycorrhizal colonization and to analyze the survival and growth of globe artichoke plantlets coming from micropropagation during the acclimatization stage. The trial was carried out in greenhouse on rooted shoots of Cynara cardunculus L. var. scolymus (L.) Fiori) cultivar 'Violet de Provence' obtained in vitro. At the time of the transplant, the microplants were inoculated with two commonly available commercial mycorrhizal inoculants with different fungal composition. Ex vitro survival (%) was measured 30 days after mycorrhizal inoculation. At the same time and at the end of the study (90 days) growth parameters were determined for each plant. Mycorrhizal colonization was evaluated microscopically after clearing the roots in 10% KOH and staining them with trypan blue in lactic acid. The results on early cultivar of artichoke 'Violet de Provence' showed survival rates and measures of morphological parameters comparable, therefore the adoption on large scale of commercial inoculants tested appears very interesting
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Nursery inoculation with the arbuscular mycorrhizal fungus Glomus viscosum and its effect on the growth and physiology of hybrid artichoke seedlings
Get PDFMost nurseries operating in Italy adopt high technologies and produce transplants that well suit and satisfy the grower’s need to produce high value crops. Mycorrhizas are discussed as a tool for improving and developing plant production in the nursery. Much research has been carried out on mycorrhizal symbiosis and we now know more about the symbiontic relationship between fungi and host plants. Plants receive numerous benefits from this symbiosis which are more macroscopic the earlier in the ontogenetic cycle this symbiosis is established. Therefore, it appears that the most effective period in which the inoculum should be made corresponds to the in-nursery growing stage. The earlier the plant is inoculated, the more evident the effect will be. In this study, several aspects related to the physiological foundations of arbuscular mycorrhiza in artichoke plants are presented. The main goal was to study the effects of mycorrhiza on the growth and physiological parameters of three hybrids of artichokes growing in the nursery. The experimental 3¥2 design included two treatments (with or without arbuscular mycorrhizal fungi) and three hybrids of artichokes marketed by Nunhems (Opal F1, Madrigal F1, Concerto F1). Mycorrhizal plants have greater shoot length, leaf area, shoot and root fresh and dry mass, and root density. This also corresponded with increased photosynthetic rates and stomatal conductance of mycorrhizal plants. Mycorrhizal colonization improves relative water content and increases proline concentration in vegetal tissue. Inoculation produced the most beneficial effect on hybrid Madrigal F1 and on hybrid Opal F1; the best mycorrhizal affinity was enhanced when compared to hybrid Concerto F1. The results showed that mycorrhizal symbiosis stimulated the growth of inoculated seedlings providing a qualitatively good propagation material
- …
