B.-E. van Wyk, N. Gericke
Hasil untuk "Botany"
Menampilkan 20 dari ~317449 hasil · dari DOAJ, Semantic Scholar, CrossRef
András Patyi, Miriam Kamp, Christine Arncken et al.
Abstract Background White lupin (Lupinus albus, L.) is a grain legume cultivated for its high agronomic and nutritional potential, despite the accumulation of bitter and potentially harmful to health quinolizidine alkaloids (QA) in the grain. Modern sweet (i.e. low alkaloid content) varieties exist, which are exploiting different recessive mutations responsible for the desired low QA chemotype. The most widely used QA-reducing determinant, pauper, has been recently identified enabling marker-assisted selection, but unstable QA content across growing seasons and environments remain a challenge in white lupin cultivation. Results Through Bulked Segregant Analysis of an F2 population, segregating for two different low QA conferring loci, we identified a novel QTL spanning a 1 Mbp region on chromosome 5, a novel source of sweetness apart from pauper. We present marker-trait associations for the new locus tagging low QA content in white lupin within this QTL, described in F2 generation and validated in F3. Together with genotyping of sweetness tagging pauper sweet individuals, we identified, in F3, 50 stacked allele recombinants where the low QA chemotype is further reduced. These individuals exhibit an exceptionally low total alkaloid content (22.8 ± 10.4 ppm), even when compared to genotypes known to carry the allele associated to the most drastic reduction in QAs, pauper (171.7 ± 18.5 ppm). Conclusion The discovery of this novel locus and the development of associated PACE markers, potentially applicable for marker-assisted selection together with pauper (especially after farther validation in a larger panel of accessions), can enhance the improvement of white lupin through the development of new varieties with very low and stable alkaloid content based on stacked allele recombinants. This can help to increase the cultivation of this useful yet underutilised crop and its use for human nutrition. Graphical abstract
Alejandro Espinoza-Tenorio
Abstract This essay examines the priorities of marine ethnobiology amid the urgent, increasingly irreversible degradation of our oceans. A dilemma arises between choosing to safeguard the practices and resources most valued for their usefulness or economic worth and prioritizing the preservation and revitalization of traditional knowledge, regardless of its immediate practical applications. I argue that the solution, from the standpoint of sustainable marine management, transcends this dichotomy. The answer lies in reviving, understanding, and transforming all the diverse knowledge systems that emerge from the relationships between humans and marine ecosystems so that urgency does not obscure our historical and holistic understanding of our connection to the sea. Marine ethnobiology bridges this divide by integrating the holistic knowledge of communities and deepening our understanding of these relationships. Strengthening place-based knowledge systems can yield critical nature-based solutions to our global environmental crisis.
Liyu Zhang, Huan He, Jiayin Wang et al.
<i>Taraxacum kok-saghyz</i> (TKS) is a natural rubber (NR)-producing plant with great development prospects. Accurately understanding the molecular mechanism of natural rubber biosynthesis is of great significance. Cis-prenyltransferase (CPT) and cis-prenyltransferase-like (CPTL) proteins catalyze the elongation of natural rubber molecular chains and play an essential role in rubber biosynthesis. In this study, we performed a genome-wide identification of the <i>TkCPT</i>/<i>CPTL</i> family, with eight <i>CPT</i> and two <i>CPTL</i> members. We analyzed the gene structures, evolutionary relationships and expression patterns, revealing five highly conserved structural domains. Based on systematic evolutionary analysis, CPT/CPTL can be divided into six subclades, among which the family members are most closely related to the orthologous species <i>Taraxacum mongolicum.</i> Collinearity analyses showed that fragment duplications were the primary factor of amplification in the <i>TkCPT/CPTL</i> gene family. Induced by ethylene and methyl jasmonate hormones, the expression levels of most genes increased, with significant increases in the expression levels of <i>TkCPT5</i> and <i>TkCPT6</i>. Our results provide a theoretical basis for elucidating the role of the <i>TkCPT</i>/<i>CPTL</i> gene family in the mechanism of natural rubber synthesis and lay a foundation for molecular breeding of <i>T. kok-saghyz</i> and candidate genes for regulating natural rubber biosynthesis in the future.
G. S. Faria, L. Carlos, S. C. Vasconcelos-Filho et al.
Abstract Hymenaea stigonocarpa Mart. ex Hayne has leaves with adaxial and abaxial epidermis covered by a very thick cuticle, in addition to anatomical structures involved in reducing the amount of herbicide absorbed by plants. Thus, we tested the hypothesis that H. stigonocarpa is potentially resistant to the herbicide glyphosate, exposing the plants to different doses (0, 96, 240, 480, and 960 g a.e ha-1). We carried out assessments of the symptoms, anatomy, growth and physiology of the plants and found that exposure to glyphosate negatively affected the height and number of leaves of the plants. Leaf fall resulted in a reduction in the photosynthetic capacity of plants, which responded by investing in stem diameter. Despite this, no visual symptoms of glyphosate toxicity were observed at the concentrations evaluated and histochemical tests did not detect signs of oxidative stress in the leaves, nor starch accumulation, indicating that carbohydrate translocation was not impaired. These results confirm our hypothesis of tolerance of H. stigonocarpa to glyphosate. Furthermore, plants exposed to the lowest doses of glyphosate (96 and 240 g ha-1) showed good growth, photosynthesis, transpiration and photochemical potential responses, indicating a hormetic effect in this application range.
Sofiene Ben Kaab, Juan Antonio Fernández Pierna, Berenice Foncoux et al.
The use of chemical herbicides induces negative impacts on the environment, animals, and human health. It also leads to the development of herbicide-resistant weeds. In this context, natural and efficacious herbicides are highly sought after. Essential oils are natural compounds with antibacterial, fungicidal, and phytotoxic properties. For this reason, we studied the post-emergence phytotoxic effect of cinnamon essential oil (cinnamon EO) from <i>Cinnamomum cassia</i> under greenhouse conditions, testing it against <i>Trifolium incarnatum</i> (<i>T. incarnatum</i>) and <i>Lolium perenne</i> (<i>L. perenne</i>). The content of malondialdehyde (MDA), percentage of water loss, electrolyte leakage, and the fluorescence of treated leaves by cinnamon EO were determined in order to understand the physiological and biochemical responses. In addition, transmission electron microscopy (TEM) was used to study the effect of cinnamon EO on cellular organelles in different tissues of <i>T. incarnatum</i> leaves. Results showed that cinnamon EO quickly induced oxidative stress in treated leaves by increasing MDA content, impacting membrane integrity and causing water loss. TEM observations confirmed the cell desiccation by cellular plasmolysis and showed an alteration of the membrane integrity and chloroplast damages. Moreover, Raman analysis confirms the disturbance of the plant metabolism by the disappearance of some scattering bands which correspond to primary metabolites. Through our finding, we confirm that cinnamon essential oil (EO) could be proposed in the future as a potential bioherbicide and a suitable source of natural phytotoxic compounds with a multisite action on weeds.
Wenfang Xu, Xiaosheng Xia, Shilong Piao et al.
Abstract It is well known that global warming increases the atmospheric water vapor content, which results in substantial changes in the hydrological cycle. Using five observational data sets, the results show that an increasing trend of near‐surface water vapor pressure (AVP) over land and ocean was significant from 1975 to 1998, while such an increasing trend in AVP subsequently weakened from 1999 to 2019. This phenomenon is associated with decreased oceanic evaporation and land surface evapotranspiration in response to recent climate variations. One consequence of such a phenomenon is a large increase in near‐surface vapor pressure deficit (VPD), which in turn increases atmospheric demand for water vapor and thus aridity and drought over land. This result emphasizes the importance of water vapor change under global warming.
Tilo Henning, Rafael Acuña-Castillo, Xavier Cornejo et al.
Documentation of plant taxa has long been subject to the temporal and spatial selectivity of professional research expeditions, especially in tropical regions. Therefore, rare and/or narrowly endemic species are sometimes known only from very few and very old herbarium specimens. However, these taxa are very important from a conservation perspective. The lack of observations of living plants and confirmation of the actual occurrence of taxa hinders the planning and implementation of effective conservation measures. Community science networks have recently made tremendous contributions to documenting biodiversity in many regions across the globe. The rediscovery of six species of Nasa (Loasaceae) from Peru and Ecuador primarily via the platform iNaturalist, is reported.
ناهید معرفزاده, هادی خاطری, سعید عباسی
Rhizoctonia root rot of common bean (Phaseolus vulgaris) caused by Rhizoctonia solani is among the most important soil-borne fungal diseases worldwide. In this study, nine arbuscular mycorrhizal fungi (AMF) including Acaulospora longula, Funneliformis mosseae, Gigaspora margarita, Glomus caledonium, G. claroideum, G. etunicatum, G. fasciculatum, G. versiform and Rhizophagus irregularis were evaluated for their effect on some growth traits and inhibition of R. solani in bean plants under greenhouse conditions. Six AMF species (F. mosseae, G. claroideum, G. etunicatum, G. margarita, G. caledonium and G. versiform) significantly reduced the disease severity index and the first four of these also reduced the incidence of disease compared with the infected control. The lowest disease severity and incidence were obtained by F. mosseae and G. claroideum, respectively. Compared with the infected control, the root length was significantly improved by all AMF. The other growth traits were also significantly improved by all AMF species with some exceptions as follows: root wet and dry weights (except G. fasciculatum), shoot wet weight (excep G. versiform), shoot length (except G. claroideum, G. versiform and G. etunicatum) and shoot dry weight (except G. etunicatum, G. fasciculatum, G. caledonium and G. margarita). Glomus fasciculatum had the highest root colonization. According to the results of this study, many AMF fungi improved plant growth and partially compensated for Rhizoctonia root rot on common bean, and they could be considered as good candidates for studying the biological control of this disease under field conditions.
Alberto Gianinetti
The phytohormone abscisic acid (ABA) inhibits seed germination and seedling growth and is required for the inception of dormancy. Xanthoxal (also known as xanthoxin) is the first specific biosynthetic precursor of ABA. In this study, a modified method to produce xanthoxal is described. I tested the ability of either xanthoxal or ABA to reinstate dormancy in dormant red rice seeds whose dormancy was broken by fluridone (an inhibitor of the synthesis of carotenoids and, subsequently, ABA). Xanthoxal was shown to have a stronger inhibitory effect on germination than ABA when exogenously provided. Although this could indicate an additional effect of xanthoxal above that expected if xanthoxal were simply converted to ABA in the seed, alternative hypotheses cannot be excluded. One alternative is that exogenous xanthoxal may be trapped inside the cells to a greater extent than exogenous ABA, resulting in an intracellular level of ABA higher than that reached with a direct application of ABA. As a further alternative, exogenous xanthoxal may interfere with ABA action in the apoplast. In this study, following germination, early seedling growth was delayed only if ABA was applied. This suggests that inhibition of early seedling growth, but not of germination, requires extracellular ABA.
Layon Oreste Demarchi, Maria Teresa Fernandez Piedade, Lucas Cardoso Marinho
ABSTRACT High species diversity, large area, and taxonomically under-studied groups are some of the explanations for the frequent discovery of new species of plants during ecological field campaigns in the Amazon region. Some of these new species are already being threatened from unplanned urban expansion associated with deforestation and habitat loss. Here we describe Tovomita cornuta, a new species discovered during ecological studies in the white-sand campinaranas of the Amazon, which is also threatened. The species is endemic to the state of Amazonas, Brazil, where it occurs in the understory of forested campinaranas physiognomies and is easily recognized by its narrowly obovoid fruits with dilated free styles. We provide a description, taxonomic and ecological comments, assessment of conservation status, geographic distribution, phenology, and illustrations for the new species.
Fahad Alharthi, Rizwan Wahab, Salim Manoharadas et al.
In order to establish the effective application of materials in a particular area, it is important to first investigate the physical and chemical properties, such as the crystallinity, structure, and the optical and surface properties. The objective of the present study is to fabricate thermally stable pyrochlore oxides, namely, lanthanum zirconate (La<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub>, LZ) and Ni-doped lanthanum zirconate (La<sub>2</sub>Zr<sub>1.5</sub>Ni<sub>0.5</sub>O<sub>7</sub>, LZN) by the solid-state and sol-gel methods. The effects of the preparation and substitution of Zr<sup>4+</sup> by Ni<sup>2+</sup> for the resulting nanocrystalline samples were characterized in terms of structure, purity, porosity, the thermal and optical properties, and photoluminescence by different techniques: XRD, FT-IR, BET, EDS, TG-DTG, UV-Vis-DRS, and PL. The XRD results confirm that the pyrochlores prepared via the sol-gel method (LZ-sg and LZN-sg) had a cubic unit-cell lattice, whereas the solid-state method (LZ-s and LZN-s) had impurities of the oxides. The XRD patterns, LZ-sg and LZN-sg, were further treated with the Rietveld technique. The textural measurements reveal that LZ-sg had a higher BET surface area compared to LZN-sg. In addition, the substitution of Zr<sup>4+</sup> by the Ni<sup>2+</sup> ion provides rational evidence for the improvement in the oxygen mobility, as well as the optical and photoluminescence properties through the lowering of the optical band energy and the electron–hole pairs.
G. P. Sunandini, Irugu Shakuntala Devi
For the study on cost of cultivation of groundnut crop in Andhra Pradesh, the data was obtained from Directorate of Economics and Statistics, Ministry of Agriculture, Government of India. The cost of cultivation was found to be Rs. 55142.26. Among the operational costs, labour cost accounted to a major share of 60%, indicating the labour intensive nature of groundnut cultivation. The cost of cultivation and the gross returns analysed during the two periods noted that cost of cultivation (C2) increased by 40% where as A2+FL increased by 52% against the increase of 25% in the gross returns. The cost of production was higher in Andhra Pradesh than other major groundnut producing states Gujarat and Tamil Nadu. The cost of cultivation needs to be reduced by opting good management practices and more mechanization so as to make groundnut cultivation profitable in Andhra Pradesh.
Yuan Zeng, Zaid Abdo, Amy Charkowski et al.
1,3-Dichloropropene (1,3-D) is a well-known nematicidal soil fumigant on many crop species. Currently, little is known about its impact on soil microbial communities using culture-free methods. In this study, we investigated changes in soil bacterial and fungal diversity and composition at two depths (30.5 and 61 cm) in response to management practices of applying 1,3-D at four different rates (103, 122, 140, and 187 liters/ha) relative to an untreated control in potato production fields using 16S rRNA and internal transcribed spacer (ITS) amplicon sequencing. A total of 12,783 operational taxonomic units (OTUs) for 16S and 1,706 OTUs for ITS were obtained. Sequencing revealed that Proteobacteria, Firmicutes, Actinobacteria, and Ascomycota were dominant phyla in soils. Comparing alpha diversity of microbial communities at the different chemical rates with untreated plots showed that bacterial communities in plots treated with 1,3-D fumigation at 140 liters/ha were richer, which was supported by higher richness indices. Other diversity indices and overall soil microbial community structure were not significantly influenced by any rates of 1,3-D fumigation, although higher bacterial and fungal richness and diversity were observed in posttreatment soils and/or at 30.5 cm. Of the identified microbial families, the differential abundance of 45 bacterial and 24 fungal families was affected by sample depth, 1,3-D rate, or the interaction of sample depth and 1,3-D. The bacterial family Enterobacteriaceae, which includes species that specialize in decay of complex carbohydrates, increased in abundance post-1,3-D fumigation, and the fungal family Ophiocordycipitaceae, which includes nematode and insect pathogens, decreased, suggesting that the nematode and soil insect death caused by fumigation may selectively impact specific fungal and bacterial families.
S.A.M. Goda Goda, M. El-Shakhs, Amira Soliman
The present study was carried out under plastic house conditions at the nursery of Zohria garden, Hort. Res. Inst., ARC, Cairo, Egypt throughout the two successive seasons of 2015 and 2016 to reveal the effect of planting dates (winter, spring, summer and autumn), some rooting promoters at different concentrations i.e. IBA, NAA, 2,4-D, catechol, cinnamic acid and tryptophan (alone or in combination) and their interactions on rooting of hard-to-root ornamental tree Phytolacca dioica.Results revealed thatplanting in spring increased rooting percentage (%) and root length (cm) in both seasons to the highest values. Treating the cuttings with IBA at 4000 ppm + NAA at 4000 ppm formulation resulted in the highest rooting percentage (%) in both seasons. Although there was no clear trend that could be observed from the obtained results, planting cuttings in either spring or autumn in addition to treating with IBA at 4000 ppm + NAA at 4000 ppm formulation increased rooting percentage (%) to the highest values.In conclusion, to achieve a successful vegetative propagation and to induce rooting on cuttings it is recommended to plant the cuttings in either spring or autumn in addition to treating with IBA at 4000 ppm + NAA at 4000 ppm formulation.
Sheir DH, Hafez MA
Candida albicans is a significant cause of morbidity and mortality in immunocompromised patients worldwide. Biofilm formation by Candida species is a significant virulence factor for disease pathogenesis. Keeping in view the importance of Streptomyces' metabolites, the present study was initiated during the bioprospecting programme of Egyptian Streptomyces carried by the authors since 2013. Native Streptomyces isolates were recovered from soil samples collected from different governorates. Antifungal activity of forty isolates of Streptomyces were performed against planktonic (free cells) of C. albicans ATCC 10231 and resistant clinical Candida isolates. Streptomyces isolates showed high inhibition activity against free cells of Candida were further assayed against biofilm of C. albicans reference strain. The most active Streptomyces sp. (no.6) was identified phenotypically, biochemically and by using 16S rRNA. The 16S rRNA sequences obtained were compared with those deposited in the GenBank Database and registered with accession number KM052378 as S. toxytricini Fz94. Screening of S. toxytricini Fz94 extract capability in prevention and destruction of C. albicans reference strain biolfilm was assessed by resazurin dye adopted technique. In the pre-exposure scheme, the lowest concentration of 5 gL-1 showed biofilm viability inhibition of 92% after 120 min, while Ketoconazole® gave 90 % inhibition at concentration of 2 gL-1. In post exposure, the concentration of S. toxytricini Fz94 extract 7gL-1 caused 82 % inhibition of biofilms viability after 120 min, while Ketoconazole did not show any destruction capability. The cytotoxicity of S. toxytricini Fz94 crude extract results showed that it was nontoxic at 10 gL-1. S. toxytricini Fz94 is maintained in the Fungarium of Arab Society for Fungal Conservation (ASFC) with accession number FSCU-2017-1110.
Anna Maria Mannino, Valentina Vaglica, Elisabetta Oddo
Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae) contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (<em>Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides</em> and <em>Padina pavonica</em>) were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga <em>D. polypodioides</em>, living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.
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