1,720,956 research outputs found
<i>Streptomyces araujoniae</i> HZ-R6, isolated from Himalayan onion (<i>Allium wallichii</i> Kunth) endorhiza, promotes growth of Chinese chive and protects from grey mould caused by <i>Botrytis cinerea</i>
No full textChinese chive (Allium tuberosum Rottler ex Spreng.), a perennial herb originating from China, is gaining popularity due to its nutritional values and medicinal properties. Grey mould caused by Botrytis cinerea, inflicts substantial economic damage upon the Chinese chive industry. Streptomyces, a ubiquitous bacterial genus that can be associated with plants, is renowned for its remarkable capability to synthesise an array of bioactive compounds. These compounds have demonstrated significant value in the realm of agricultural applications. Nevertheless, studies emphasised the exploration of eco-friendly management approaches, such as biocontrol microorganisms and plant growth-promoting bacteria (PGPB) specifically for Chinese chive, still subject to restrictions to this day. In our study, 21 endophytic Streptomyces strains, identified by molecular methods and morphological analysis, were isolated from Himalayan onion (Allium wallichii Kunth) collected from Jiucaiping mountain, Guizhou, China. Among them, S. araujoniae HZ-R1, HZ-R3, HZ-R6, HZ-R10, and HZ-S2 illustrated strong antagonistic activity (≥50 per cent of mycelium growth inhibition) against Botrytis cinerea in vitro. Additionally, S. araujoniae HZ-R6 showed remarkable growth-promoting capabilities by directly increasing plant biomass and indirectly enhancing various physiological properties. Leveraging its potential as biostimulant, we assessed the efficacy of S. araujoniae HZ-R6 against B. cinerea on Chinese chives in a greenhouse setting. A statistically significant 43.28% reduction in disease incidence and disease index was observed in the treatment group compared to the control group. Our findings suggests that S. araujoniae HZ-R6 has great potential to be further considered as a biofertilizer or biofungicide for the production of Chinese chives.</p
First report of <i>Fusarium foetens</i> causing tobacco root and stem rots in Guizhou, China
No full textIn September of 2019, root and stem rots were observed in tobacco plants in Xingren, Guizhou Province, China. Typical symptoms included rotted roots and stems, failure to form vascular bundles or complete necrosis of vascular bundle tissues, and the plant later showed hollow stems and complete wilt. In a 0.13-ha field, the disease incidence was 50%–60%, causing serious economic losses. Based on morphological characteristics and molecular identification, as well as confirmation of pathogenesis following Koch's postulates, the causal agent was identified as Fusarium foetens. To our knowledge, this study is the first report of F. foetens as a pathogen on tobacco causing root and stem rot in Guizhou, China. The identification of the pathogen could lay the basis for its sustainable management in future.</p
Co-exposure to microplastics and soil pollutants significantly exacerbates toxicity to crops: Insights from a global meta and machine-learning analysis
No full textEnvironmental contamination of microplastics (MPs) is ubiquitous worldwide, and co-contamination of arable soils with MPs and other pollutants is of increasing concern, and may lead to unexpected consequences on crop production. However, the overall implications of this combined effect, whether beneficial or detrimental, remain a subject of current debate. Here, we conducted a global meta and machine-learning analysis to evaluate the effects of co-exposure to MPs and other pollutants on crops, utilizing 3346 biological endpoints derived from 68 different studies. Overall, compared with control groups that only exposure to conventional soil contaminants, co-exposure significantly exacerbated toxicity to crops, particularly with MPs intensifying adverse effects on crop morphology, oxidative damage, and photosynthetic efficiency. Interestingly, our analysis demonstrated a significant reduction in the accumulation of pollutants in the crop due to the presence of MPs. In addition, the results revealed that potential adverse effects were primarily associated with crop species, MPs mass concentration, and exposure duration. Our study reaffirms the substantial consequences of MPs as emerging pollutants on crops within the context of integrated pollution, providing novel insights into improving sustainability in agro-ecosystems.</p
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
The larval gut of <i>Spodoptera frugiperda </i>harbours culturable bacteria with metabolic versatility after insecticide exposure
No full textSpodoptera frugiperda (fall armyworm) poses a substantial risk to crops worldwide, resulting in considerable economic damage. The gut microbiota of insects plays crucial roles in digestion, nutrition, immunity, growth and, sometimes, the degradation of insecticides. The current study examines the effect of synthetic insecticides on the gut microbiome of third instar S. frugiperda larvae using both culture-dependent techniques and 16S rRNA gene sequencing for bacterial community profiling and diversity analysis. In untreated larvae, the sequencing approach revealed a diverse microbiome dominated by the phyla Firmicutes, Proteobacteria and Bacteroidota, with key genera including Bacteroides, Faecalibacterium and Pelomonas. In parallel, 323 bacterial strains were isolated and assigned to the orders Bacillales, Burkholderiales, Enterobacterales, Flavobacteriales, Lactobacillales, Micrococcales, Neisseriaies, Pseudomonadales, Sphingobacteriales and Xanthomonadales. The prevailing culturable species included Serratia marcescens, Klebsiella variicola and Enterobacter quasiroggenkampii. Treatment with sublethal concentrations of three insecticides (broflanilide, spinosad and indoxacarb) caused significant changes in gut microbiome diversity and composition. Treated larvae showed a shift towards increased Proteobacteria abundance and decreased Firmicutes. Specifically, Acinetobacter and Rhodococcus were dominant in treated samples. Functional predictions highlighted significant metabolic versatility involving nutrient processing, immune response, detoxification, xenobiotic metabolism, and stress response, suggesting microbial adaptation to insecticide exposure. Network correlation analysis highlighted disrupted microbial interactions and altered community structures under insecticide treatment. These findings enhance our understanding of how insecticides impact the gut microbiota in S. frugiperda and may inform future strategies for managing pest resistance through microbiome-based approaches.</p
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