1,720,975 research outputs found
Characterization of microorganisms with PGP characteristics and their survival in the rhizosphere
Get PDFPGP mikroorganizmi (Plant Growth Promoting) su predmet mnogobrojnih istraživanja, čiji je glavni cilj pronalaženje adekvatnog načina njihove primene u poljoprivredi, hortikulturi, šumarstvu i zaštititi životne sredine. Cilj ovih istraživanja bio je izolacija i karakterizacija mikroorganizama sa PGP svojstvima iz rizosfere engleskog ljulja, ispitivanje sposobnosti njihovog preživljavanja nakon unošenja u zemljište, kao i praćenje uticaja njihove primene na parametre prinosa i mikrobiološku aktivnost u rizosferi biljke. Karakterizacija izolata roda Pseudomonas, Bacillus i Streptomyces obuhvatila je određivanje fizioloških, biohemijskih i PGP osobina. Uticaj introdukcije odabranih izolata i gljive Trichoderma asperellum na brojnost i mikrobiološku aktivnost u rizosferi engleskog ljulja, određivan je standardnim metodama na selektivnim hranljivim podlogama, a dehidrogenazna aktivnost spektrofotometrijskom metodom. U laboratorijskim uslovima ispitivan je efekat primene izolata na klijavost, dužinu korenka i stabaoca klice semena engleskog ljulja. U toku godine, uzimana su tri otkosa i pri tome su određivani dužina nadzemnog dela i korena biljke (cm) i prinos zelene i suve materije nadzemnog dela biljke po otkosu (t/ha). Na osnovu morfoloških, fiziološko-biohemijskih, kao i PGP osobina koje su izolati pokazali, te na osnovu rezultata mnogobrojnih dosadašnjih istraživanja, može se zaključiti da izolati P1 i P9 pripadaju vrsti Pseudomonas putida, izolat P12 Pseudomonas fluorescens, izolati B1, B3 i B6 vrsti Bacillus subtilis, a izolati A1, A2, A3 rodu Streptomyces. Brojnost pojedinih sistematskih i fizioloških grupa mikroorganizama kao i enzimatska aktivnost u rizosferi engleskog ljulja, zavisila je od primenjenih inokulanata. Primena izolata Pseudomonas sp. P12 pozitivno je uticala na povećanje ukupnog broja mikroorganizama, brojnost gljiva, aminoheterotrofa i aktinomiceta. Izolat Bacillus sp. B1 uticao je na povećanje ukupnog broja mikroorganizama, brojnosti gljiva i azotobaktera. Primena izolata Streptomyces sp. A3 dovela je do povećanja broja aktinomiceta i oligonitrofila, dok je primena Trichoderma asperellum uticala pozitivno na povećanje broja aminoheterotrofa i azotobaktera. Primena izolata Pseudomonas sp. P12 i Streptomyces sp. A3 imala je najveći efekat na dehidrogenaznu aktivnost. Inokulacija je imala pozitivan uticaj na klijavost, svežu i suvu masu biljke, visinu i dužinu korena biljaka. Primena gljive Trichoderma asperellum i izolata Streptomyces sp. A3 delovala je pozitivno na klijavost, dužinu korenka i stabaoca klice. U proseku, najbolji efekat na prinos sveže i suve materije, kao i na visinu nadzemnog dela i dužinu korena biljke, imala je primena izolata Pseudomonas sp.P12 i Bacillus sp. B1.U proizvodnji krmnih trava mikroorganizmi još nisu našli značajniju praktičnu primenu iako je veći i kvalitetniji prinos jedan od ciljeva stočarske proizvodnje. Rezultati ovih istraživanja su pokazali da se primenom mikroorganizama mogu postići pozitivni efekti i u proizvodnji engleskog ljulja. Zbog toga je veoma značajno da se vrše dalja ispitivanja uzajamnog odnosa primenjenih mikroorganizama i engleskog ljulja u poljskim uslovima, kako bi se optimizirao način i vreme primene inokulanataPGP microorganisms (Plant Growth Promoting) have been the subject of many research projects, whose main goal is to find appropriate methods of their use in agriculture, horticulture, forestry and environmental protection. The aim of this study is the isolation and characterization of microorganisms with PGP characteristics from the rhizosphere of perennial ryegrass, testing their ability to survive after entering the soil, and monitoring the impact of their application on yield parameters and microbial activity in the rhizosphere of plants. Characterization of Pseudomonas, Bacillus and Streptomyces included determination of the physiological, biochemical and PGP characteristics. Impact of the introduction of selected isolates and fungi Trichoderma asperellum on quantity and microbial activity in the rhizosphere of ryegrass was determined by using the standard method of selective media; dehydrogenase activity by the spectrophotometric method. The effects of the implementation of isolates on germination, seedling length sprouts seeds of perennial ryegrass were studied under laboratory conditions. During the year, three cuttings were taken. At each of the three cuttings, length of stem and roots of plants (cm) and yields of fresh and dry matter of the plant (t / ha) were measured. Based on morphological, physiological and biochemical characteristics and PGP characteristics observed in the isolates, and based on the results of many previous studies, it can be concluded that (1) P1 and P9 isolates belong to the species Pseudomonas putida, (2)Pseudomonas fluorescens P12 isolate, isolates of B1, B3, B6, belong to the species Bacillus subtilis, and (3) A1, A2 and A3 isolates belong to the ordo Streptomyces. The quantity of systematic and physiological groups of microorganisms and enzymatic activity in the rhizosphere of ryegrass depended on the applied inoculants. Application of Pseudomonas sp. P12 had positive effects on increasing the total number of microorganisms, fungi, aminoheterotrophs and actinomycetes. Isolate Bacillus sp. B1 affected the increase of the total number of micro-organisms in the fungi and Azotobacter. Application of Streptomyces sp. isolates A3 led to an increase in the number of actinomycetes and oligonitrophyls, while the application of Trichoderma asperellum had positive impact on increasing the number aminoheterotrophs and Azotobacter. Application of Pseudomonas sp. P12 and Streptomyces sp. A3 had the greatest effect on dehydrogenase activity. Inoculation had a positive effect on germination, fresh and dry weight of plant, height and rootlength of plants. Introduction of fungus Trichoderma asperellum and Streptomyces sp. A3 isolate acted positively on germination, length of seedling of germs. On average, the best effects on the yield of fresh and dry matter, the height of the stem of the plant and the length of the root were attained by the application of Pseudomonas sp.P12 and Bacillus sp. B1 isolates. Microorganisms have not yet found significant practical use in the production of forage grasses, even though more qualitative yield has been sought in livestock production. The results of this study demonstrate that positive results in the production of perennial ryegrass can be achieved by the use of microorganisms. Therefore, it is very important to carry out further studies of the relationship between applied microorganisms and ryegrass under field conditions in order to optimize the method and time of application of inoculants
Characterization of microorganisms with PGP characteristics and their survival in the rhizosphere
No full textPGP mikroorganizmi (Plant Growth Promoting) su predmet mnogobrojnih istraživanja, čiji je glavni cilj pronalaženje adekvatnog načina njihove primene u poljoprivredi, hortikulturi, šumarstvu i zaštititi životne sredine. Cilj ovih istraživanja bio je izolacija i karakterizacija mikroorganizama sa PGP svojstvima iz rizosfere engleskog ljulja, ispitivanje sposobnosti njihovog preživljavanja nakon unošenja u zemljište, kao i praćenje uticaja njihove primene na parametre prinosa i mikrobiološku aktivnost u rizosferi biljke. Karakterizacija izolata roda Pseudomonas, Bacillus i Streptomyces obuhvatila je određivanje fizioloških, biohemijskih i PGP osobina. Uticaj introdukcije odabranih izolata i gljive Trichoderma asperellum na brojnost i mikrobiološku aktivnost u rizosferi engleskog ljulja, određivan je standardnim metodama na selektivnim hranljivim podlogama, a dehidrogenazna aktivnost spektrofotometrijskom metodom. U laboratorijskim uslovima ispitivan je efekat primene izolata na klijavost, dužinu korenka i stabaoca klice semena engleskog ljulja. U toku godine, uzimana su tri otkosa i pri tome su određivani dužina nadzemnog dela i korena biljke (cm) i prinos zelene i suve materije nadzemnog dela biljke po otkosu (t/ha). Na osnovu morfoloških, fiziološko-biohemijskih, kao i PGP osobina koje su izolati pokazali, te na osnovu rezultata mnogobrojnih dosadašnjih istraživanja, može se zaključiti da izolati P1 i P9 pripadaju vrsti Pseudomonas putida, izolat P12 Pseudomonas fluorescens, izolati B1, B3 i B6 vrsti Bacillus subtilis, a izolati A1, A2, A3 rodu Streptomyces. Brojnost pojedinih sistematskih i fizioloških grupa mikroorganizama kao i enzimatska aktivnost u rizosferi engleskog ljulja, zavisila je od primenjenih inokulanata. Primena izolata Pseudomonas sp. P12 pozitivno je uticala na povećanje ukupnog broja mikroorganizama, brojnost gljiva, aminoheterotrofa i aktinomiceta. Izolat Bacillus sp. B1 uticao je na povećanje ukupnog broja mikroorganizama, brojnosti gljiva i azotobaktera. Primena izolata Streptomyces sp. A3 dovela je do povećanja broja aktinomiceta i oligonitrofila, dok je primena Trichoderma asperellum uticala pozitivno na povećanje broja aminoheterotrofa i azotobaktera. Primena izolata Pseudomonas sp. P12 i Streptomyces sp. A3 imala je najveći efekat na dehidrogenaznu aktivnost. Inokulacija je imala pozitivan uticaj na klijavost, svežu i suvu masu biljke, visinu i dužinu korena biljaka. Primena gljive Trichoderma asperellum i izolata Streptomyces sp. A3 delovala je pozitivno na klijavost, dužinu korenka i stabaoca klice. U proseku, najbolji efekat na prinos sveže i suve materije, kao i na visinu nadzemnog dela i dužinu korena biljke, imala je primena izolata Pseudomonas sp.P12 i Bacillus sp. B1.U proizvodnji krmnih trava mikroorganizmi još nisu našli značajniju praktičnu primenu iako je veći i kvalitetniji prinos jedan od ciljeva stočarske proizvodnje. Rezultati ovih istraživanja su pokazali da se primenom mikroorganizama mogu postići pozitivni efekti i u proizvodnji engleskog ljulja. Zbog toga je veoma značajno da se vrše dalja ispitivanja uzajamnog odnosa primenjenih mikroorganizama i engleskog ljulja u poljskim uslovima, kako bi se optimizirao način i vreme primene inokulanataPGP microorganisms (Plant Growth Promoting) have been the subject of many research projects, whose main goal is to find appropriate methods of their use in agriculture, horticulture, forestry and environmental protection. The aim of this study is the isolation and characterization of microorganisms with PGP characteristics from the rhizosphere of perennial ryegrass, testing their ability to survive after entering the soil, and monitoring the impact of their application on yield parameters and microbial activity in the rhizosphere of plants. Characterization of Pseudomonas, Bacillus and Streptomyces included determination of the physiological, biochemical and PGP characteristics. Impact of the introduction of selected isolates and fungi Trichoderma asperellum on quantity and microbial activity in the rhizosphere of ryegrass was determined by using the standard method of selective media; dehydrogenase activity by the spectrophotometric method. The effects of the implementation of isolates on germination, seedling length sprouts seeds of perennial ryegrass were studied under laboratory conditions. During the year, three cuttings were taken. At each of the three cuttings, length of stem and roots of plants (cm) and yields of fresh and dry matter of the plant (t / ha) were measured. Based on morphological, physiological and biochemical characteristics and PGP characteristics observed in the isolates, and based on the results of many previous studies, it can be concluded that (1) P1 and P9 isolates belong to the species Pseudomonas putida, (2)Pseudomonas fluorescens P12 isolate, isolates of B1, B3, B6, belong to the species Bacillus subtilis, and (3) A1, A2 and A3 isolates belong to the ordo Streptomyces. The quantity of systematic and physiological groups of microorganisms and enzymatic activity in the rhizosphere of ryegrass depended on the applied inoculants. Application of Pseudomonas sp. P12 had positive effects on increasing the total number of microorganisms, fungi, aminoheterotrophs and actinomycetes. Isolate Bacillus sp. B1 affected the increase of the total number of micro-organisms in the fungi and Azotobacter. Application of Streptomyces sp. isolates A3 led to an increase in the number of actinomycetes and oligonitrophyls, while the application of Trichoderma asperellum had positive impact on increasing the number aminoheterotrophs and Azotobacter. Application of Pseudomonas sp. P12 and Streptomyces sp. A3 had the greatest effect on dehydrogenase activity. Inoculation had a positive effect on germination, fresh and dry weight of plant, height and rootlength of plants. Introduction of fungus Trichoderma asperellum and Streptomyces sp. A3 isolate acted positively on germination, length of seedling of germs. On average, the best effects on the yield of fresh and dry matter, the height of the stem of the plant and the length of the root were attained by the application of Pseudomonas sp.P12 and Bacillus sp. B1 isolates. Microorganisms have not yet found significant practical use in the production of forage grasses, even though more qualitative yield has been sought in livestock production. The results of this study demonstrate that positive results in the production of perennial ryegrass can be achieved by the use of microorganisms. Therefore, it is very important to carry out further studies of the relationship between applied microorganisms and ryegrass under field conditions in order to optimize the method and time of application of inoculants
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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
