1,720,961 research outputs found
Mycorrhizal fungi effectiveness on micropropagated artichoke plantlets
No full textMycorrhizas give positive effects on survival and growth rates during acclimatization of many micropropagated species, such as artichoke. To improve these benefits, it is very important the selection of the most appropriate mycorrhizal fungus. Mycorrhizal effectiveness, in fact, depends on the compatibility between fungus and plant.
In this research the effectiveness of two mycorrhizal fungus isolates (Glomus intraradices or Glomus viscosum) on micropropagated artichoke plantlets during acclimatization was investigated.
Micropropagated plantlets of Cynara cardunculus var. scolymus Fiori of the “Locale di Mola” type were acclimatized in a climatic greenhouse. At the time of transplanting in pot Glomus intraradices or Glomus viscosum were added to peat and perlite (2:1 v/v ratio) and compared with untreated plants
The effect of mycorrhizal fungi on growth (fresh and dry weights of shoot and root; the total leaf area, root length and density), chlorophyll content values (SPAD–502 portable chlorophyll meter; Minolta Camera Co.LTD) and gas exchange (Leaf porometer SC-1 Decagon Device) in the leaves was determined each month.
The results obtained confirm the positive role of AM fungi colonization on survival and growth rate during acclimatization of artichoke plantlets.
The higher SPAD is strictly related to an higher photosynthetic potential for mycorrhizal plants and consequently to their better nutrient status due to the symbiotic affinity recorded especially with Glomus viscosum inoculation. According to these results the growing of the plantlets results improved by the use of Glomus viscosum in the host-fungus combination.
Finally, mycorrhizal plantlets showed higher stomatal conductance probably necessary to supply the carbon needs of fungal symbionts without significant difference between the two fungus species
Influence of mycorrhizal inoculation on the salt tolerance of hybrid artichoke seedlings
No full textIn the Mediterranean region many horticultural crops as well as artichoke have to cope with increasing salinization of irrigation water.
Arbuscular mycorrhizal fungi (AMF) are known to improve plant tolerance to salt stress in some crops.
In this study, the role of mycorrhizal symbiosis in the alleviation of salinity stress induced by sodium chloride (NaCl) in three hybrid artichokes, Madrigal F1, Opal F1 and Concerto F1 (Nuhems company), was examined.
The root systems of 2- month-old artichoke plantlets, with or without mycorrhizal fungus (Glomus viscosum), were placed in distilled water enriched with different salt concentrations (0, 50, 100, 150, 200 mM NaCl) to study the wilting response.
To study the wilting trend, a visual rating system was developed defining the following wilting indexes: T0, no wilting; T1, foliar damage on less than 50% of vegetal tissues of oldest leaves; T2, initial wilting and foliar damage on more than 50% of vegetal tissues of oldest leaves; T3, foliar damage on youngest leaves; T4, total wilting. The required time to reach different wilting indexes was monitored both for mycorrhizal and not-mycorrhizal plants.
Electrolyte leakage by leaves was assessed 28 hours after stress imposition to estimate the extent of cell damage induced by salt. Electrolyte leakage was performed on young and old leaves to evaluate the different foliar damage that visual analysis showed.
The mycorrhizal symbiosis improves tolerance to salt stress in all hybrid artichoke seedlings tested. However the results show a different sensitivity among Madrigal F1, Opal F1 and Concerto F1.
The greatest tolerance observed in inoculated plants could be in agreement with the improvement of growth stimulated by mycorrhizal symbiosis, which lead to the resulting dilution of toxic ions
Field performance of micropropagated and mycorrhizal plants of early artichoke “Violet de Provence”
No full textOne of the most important problems of micropropagated early Mediterranean artichokes was found in the phenotypical and behavioural variations in the field which determined the loss of earliness at harvest and consequently a lack of interest in using this method of propagation.
The present work aimed to establish an efficient protocol for the micropropagation and the mycorrhizal inoculation of Cynara cardunculus L. var. scolymus Fiori cultivar “Violet de Provence” and to evaluate in-field assessment of the plants.
Microrosettes of “Violet de Provence” were established in vitro on a nutrient medium enriched with isopentil adenine (2ip), indoleacetic acid (IAA) and gibberellic acid (GA3). The shoots were subcultured in the some medium supplemented with 6-benzylaminopurine (BAP), while, for root induction, indoleacetic acid (IAA) was used. At the time of transplant in greenhouse, the plantlets were inoculated or not with Glomus viscosum strain A6 (AM fungus).
4-month-old micropropagated plantlets were transferred to the field at the end of summer and morphological and productive parameters were investigated.
The results obtained in the first year showed an uniform growth in the field of the artichoke plants, both phenotypically and in their behaviour, and a maintenance of the earliness.
The use of this technique in early types
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
