Examinando por Autor "Guerra-Sierra, Beatriz Elena"
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- PublicaciónAcceso abiertoActinobacteria-enhanced plant growth, nutrient acquisition, and crop protection: Advances in soil, plant, and microbial multifactorial interactions(2022-02-05) Mitra, Debasis; MondaL, Rittick; Khoshru, Bahman; Senapati, Ansuman; Radha, T. K.; Mahakur, Bhaswatimayee; Uniyal, Navendra; Myo, Ei Mon; Boutaj, Hanane; Guerra-Sierra, Beatriz Elena; Panneerselvam, Periyasamy; Ganeshamurthy, Arakalagud Nanjundaiah; Andelković, Snežana; Vasić, Tanja; Rani, Anju; Dutta, Subhadeep; Das Mohapatra, Pradeep K.; MicrobiotaAgricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today's huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs. In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants. The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.
- PublicaciónAcceso abiertoActividad Acaricida In Vitro de Compuestos Sobre Schizotetranychus hindustanicus(Hirst), (Acari: Tetranychidae), Ácaro Hindú de los Cítricos(2022-02-01) Ortiz-Meneses, Fredy Alejandro; Guerra-Sierra, Beatriz Elena; Osorio-Alvarado, Carlos Enrique; Rodriguez-Gonzalez, Leidy; MicrobiotaEl cultivo de lima Tahití(Citrus x latifolia Tanaka ex Q. Jiménez)ocupa un importante porcentaje dentro de la cadenacomercialde los cítricos en Colombia, pero es atacado por Schizotetranychus hindustanicus o ácarohindú, un fitófago que produce lesiones típicas en el haz de las hojas y frutos, caracterizadas por manchas blanquecinas circulares que corresponden a las telarañas que teje la hembra y que le restan valor estético al fruto y a su comercialización. El objetivo del presente estudio consistió en evaluar in vitrolos efectos acaricidas de distintos compuestos en tres tiempos de contacto sobre poblaciones del ácaro.Se evaluó extracto oleaginoso de Neem (Azadirachta indica)al 1,0%, azufre micronizado al 0,5%, extracto acuoso de Azadirachtina 0,4%, filtrado de caldo de ceniza al 15 %. Como control positivo se utilizó Abamectina al 0,2%, producto reconocido por su efecto acaricida, y se usó agua destilada como control negativo. Se evidenció que los tratamientos más efectivos fueronelextracto oleaginoso de Neem-A. indicaal1,0%, azufre micronizado al 0,5%, y Abamectina al 0,2% con valores de mortalidad del 96,4;97,9 y100 % a las 72 horasrespectivamente. Los resultados permiten sugerir el uso de compuestos naturales a base de Azadirachta indicaen soluciones oleaginosas para el control deesta plaga, pues no afectan el ecosistema a la vez que no se han reportado resistencias del fitófago por su uso.
- PublicaciónAcceso abiertoAlteraciones histopatológicas causadas por la roya puccinia nakanishikii (Pucciniales: pucciniaceae) en plantas de cymbopogon citratus (poaceae)(2020-02-13) Rincón-Barón, Edgar Javier; Gutierrez-Rodriguez, Ana Mariany; Guerra-Sierra, Beatriz Elena; Espinosa Matías, Silvia; MicrobiotaHistopathological alterations caused by Puccinia nakanishikii rust (Pucciniales: Pucciniaceae) in Cymbopogon citratus (Poaceae) plants. Introduction: Histopathological and histochemical aspects linked to the attack of fungal rusts to plants, as well as its relation with the different spore stages are topics rather scarce in the scientific literature. Objective: To describe and analyze the histopathological and histochemical aspects of Cymbopogon citratus and its relation with the different stages of the spores from the rust fungi Puccinia nakanishikii. Methods: During the months April and August 2013, leaves healthy and infected by Puccinia nakanishikii were collected in the Northwestern scarp of the Bucaramanga-Colombia plateau. The samples with injuries on diverse developmental stages were fixated and processed according to the standard protocols for embedding and sectioning in paraffin and resin. Sections obtained from paraffin (5-7 μm) were stained with Safranin-Alcian blue and Alcian blue-Hematoxylin. On the other hand, sections obtained from resin (0.5 μm) were stained with Toluidine blue. Further, freehand sections were obtained for an autofluorescence analysis. The observations and photographic record were done via photonic microscope and epifluorescence microscope. For the observations via scanning electron microscopy (SEM), the samples were fixated in Glutaraldehyde, dehydrated with 2,2 dimethoxypropane, then desiccated to critical point and finally coated with gold. Results:The leaves are generally hypostomatic, with long and short epidermic cell forming parallel rows and showing unicellular prickle trichomes and micro-trichomes. The abaxial surface is covered by epicuticular wax forming a dense layer. The adaxial epidermis is formed by groupings of bulliform cells and epidermal cells with rectangu-lar or squared contour. In the mesophyll, there is no differentiation between palisade and spongy parenchyma, its anatomy reflects the C4 metabolism. The formation of uredosori and teliosori both hypophyllous was observed. Urediniospores are the reinfecting agents phase, they have 4-5 equatorial germ pores and echinulate wall. Teliospores have smooth wall and a persistent pedicel. The urediniospores form a germ tube, generally on the abaxial leaf surface, these tubes develop towards the stomata reaching the mesophyll interior. No appressorium were observed. The epidermis limiting the uredosorus detaches due the development and pressure that exert both the urediniospores and capitate paraphyses. As the infection progresses, autofluorescense of the chloro-phyll is lost and the cells undergo necrotic processes. Afterwards, the phloem collapses and the xylem becomes slightly disorganized. At this moment, the infection is extended along the whole leaf blade, resulting in the leaf death and the plant defoliation. On advanced stages of the infection, the uredosori showed pycnidia, probably belonging to the hyperparasite Sphaerellopsis, these structures were closely associated to the rust infected tissues. Conclusions:Puccinia nakanishikii develops on the leaves of Cymbopogon citratus producing uredosori and teliosori. Urediniospores are the reinfective stage, teliospores were only observed at late stages of the infection. The epidermis and photosynthetic tissue are severely affected by cell necrosis. The vascular tissues are deeply affected on the advances stages of the infection.
- PublicaciónAcceso abiertoAntifungal activity of acidic electrolyzed water against strawberry postharvest molds (Fragaria x ananassa Duch cv. Camarosa)(2019-04-01) Guerra-Sierra, Beatriz Elena; Sandoval-Meza, Adriana Ximena; García-Sanchéz, Liliana Torcoroma; MicrobiotaThe aim of this word was to assess the in vitro antifungal activity of acidic electrolyzed water (AEW) and the required contact time to inhibit the development of post-harvest molds common in strawberry fruit. Ninetyfour strawberry samples were used. A five-fold assay in a randomized design was carried out using standard inoculum of fungal conidia, which were subjected to an array of contact times and AEW concentrations, using a controlled agitation (120 r.p.m) at 23°C. The conidia treated with AEW were grown on potato dextrose agar and their germination was evaluated. Mycelial growth of the treated samples was measured and compared against conidia control samples treated with distilled water instead of AEW. Botrytis cinerea and Rhizopus stolonifer were the most commonly isolated species at 54.25% and 28.72%, respectively. AEW inhibited conidia germination after 7 minutes of exposure. The AEW concentration required to inhibit conidia germination was 10 ppm and 50 ppm for R. stolonifer and B. cinerea respectively, a variance possibly due to the constitution of their cellular walls. A short exposure of AEW is able to inhibit post-harvest fungi growth, and is thus recommended as an efficient, economical, and environmentally sustainable sanitation agent, with the ability of extending the strawberry postharvest consumption period.
- PublicaciónAcceso abiertoArbuscular mycorrhizal fungal association boosted the arsenic resistance in crops with special responsiveness to rice plant(2022-01-05) Mitra, Debasis; Saritha, Boya; Janeeshma, Edappayil; Gusain, Poonam; Khoshru, Bahman; Abo Nouh, Fatma A.; Rani, Anju; Olatunbosun, Adeyemi N.; Ruparelia, Janki; Rabari, Aniruddh; Mosquera-Sánchez, Lyda P.; Mondal, Rittick; Verma, Devvret; Panneerselvam, Periyasamy; Das Mohapatra, Pradeep K.; Guerra-Sierra, Beatriz Elena; MicrobiotaArsenic (As) is a potentially toxic metalloid classified as a group 1 carcinogen, released in the soil environment because of natural as well as different anthropogenic activities. The presence of excess As content in soil and irrigation water enhances the As accumulation in rice grains. Millions of people who consume these contaminated grains are exposed to severe health issues. Increased arsenic uptake causes oxidative stress in plants, which combats by inducing the expression of several genes and signaling the biosynthesis of various antioxidants and phytochelatins. As toxicity reduces crop productivity, so it's critical to improve plant growth in As-contaminated environments while minimizing metal translocation to grains. Arbuscular mycorrhiza fungi (AMF) is considered a sustainable way to tolerate As toxicity. Organic pollutants metabolism by AMF, degradation of these soil contaminants by AMF exudation enzymes, and elimination of the pollutants by plant uptake and accumulation are the principal mechanisms of AMF mediated bioremediation. However, plant responses are established to vary with the host plant and the species of AMF. In our review, we showed that understanding the community composition, diversity, and gene regulation of AMF in the rice ecosystem played a critical role in maximizing As uptake and their potential in sustainable rice and other crops production. It has been reviewed that AMF has the potential to survive in an extremely As toxic condition and it potentially aids to improve the tolerance level of host plants.
- PublicaciónAcceso abiertoBioconversión de Residuos Agrícolas por Micelio Fúngico Para la Elaboración de Prototipos de Bioproductos(Universidad de Santander, 2023-09-15) Caicedo-Jiménez, Nazly Julieth; Guerra-Sierra, Beatriz Elena; Ortíz-Meneses, Fredy Alejandro; Contreras-Contreras,Sandra Lorena; Grupo microbiotaDiferentes residuos generados por la industria son vertidos diariamente al ambiente en cantidades desmesuradas, impactando negativamente la calidad de vida, el ambiente y la sostenibilidad en el planeta. Un ejemplo es el poliestireno expandido o icopor, utilizado ampliamente a nivel global como material de empaquetado y construcción entre otros usos. Este material ocasiona alta contaminación, debido al espacio ocupado en los vertederos y su difícil degradación. Por lo tanto, el propósito de este trabajo fue generar un bioproducto para mitigar la creciente contaminación por poliestireno, aprovechando el potencial que ofrecen los diversos residuos postcosecha derivados de la agricultura Colombiana, para ser utilizados como sustratos en los procesos de bioconversión enzimática por G. lucidum y P. ostreatus , macromicetos reconocidos por la producción de enzimas hidrolíticas y oxidativas tales como lacasas, peroxidasas de manganeso y peroxidasas de lignina, hemicelulasas, entre otras. Para este propósito se realizaron diferentes tratamientos o mezclas en partes iguales de residuos de la caña (bagazo) cacota de cacao, cascara de Sacha inchi, aserrín y una fuente de nitrógeno, como sustratos de fácil adquisición y bajo costo en los que se desarrollaron los micelios de los macromicetos para su bioconversión bajo un sistema estandarizado de humedad, CO2, y temperatura. En este trabajo se obtuvo un bioproducto con características físico-mecánicas similares al poliestireno expandido, sugiriendo continuar con los ensayos en el grupo de investigación para optimizar las características de resistencia otorgadas por las diferentes formulaciones de residuos agrícolas, que son una fuente disponible, de bajo costo, biodegradables que sirven como sustrato para la elaboración de bioproductos sostenibles y amigables con el medio ambiente.
- PublicaciónAcceso abiertoEvaluación de la capacidad Fotosintética de Heliconiapsittacorum (L.f.) asociada a Rhizophagus irregularis y Asperguillus niger en suelos impactados por cadmio(Bucaramanga : Universidad de Santander, 2018, 2018-06-28) Aguillón Almario, Diana Marcela; García Castro, Stefanía; Guerra-Sierra, Beatriz ElenaThe presence of an excessive amount of cadmium in the soil causes various symptomatology in plants, such as reduced growth especially root growth alterations in mineral nutrition and carbohydrate metabolism and can therefore strongly reduce biomass production. This reduction of the biomass due to the toxicity of cadmium (Cd) could be one of the most important consequences in the inhibition of chlorophyll synthesis and in the decrease of the photosynthetic rate of the plants. That is why the association of arbuscular mycorrhizal fungi with the plant confers nutritional benefits and resistance to different stress factors, both biotic and abiotic. The objective of the present was to study the capacity of photosynthetic production in plants of Heliconia psittacorum in association with mycorrhizal fungi under light and shade conditions, in three soils naturally impacted by cadmium (0.96, 1.075, 18.83 ppm) present in the native soils of San Vicente de Chucuri. In this work the response variables were evaluated such as mycorrhizal symbiosis, total chlorophyll amount, physiological differences in leaf growth and stem length and quantification of root biomass. The factors evaluated allowed to show that each of the treatments for each factor such as concentration of cadmium, inoculated and light source is correlated and present significant differences among themselves. In conclusion, the use of mycorrhizae in soil contaminated with cadmium increases the photosynthetic capacity and favors the growth and development of the plant as well as its root biomass, since this symbiosis retains help to retain cadmium, preventing it from being disturbed to other parts of the soil. The plant, likewise it is important to mention that the photosynthetic rate was not affected by the concentration of cadmium present in the soil.
- PublicaciónAcceso abiertoEvaluación de la patogenicidad de Xenorhabdus spp. nativos en Colombia(2014-07) Guerra-Sierra, Beatriz Elena; Chacón, Julie Giovanna; Muñoz Flórez, Jaime Eduardo; Caicedo, Ana MilenaXenorhabdus and Photorhabdus bacteria are symbiotically associated with nematodes of the Steinernematidae and Heterorhabditidae families respectively. They are characterized by producing a complex of substances such as toxins, antibiotics and extracellular enzymes that kill insects. In order to select the most pathogenic nematodes and antibiotic production level, it was propose to evaluate the pathogenicity of 13 native isolates. Bacteria were isolated from infective juveniles (JIS) by direct macerated, cultured on selective media (NBTA and MacConkey) and described phenotypic and biochemically. The pathogenicity was evaluated on the last instar larvae of G. mellonella, using serial dilutions of the bacterial inoculum with a concentration of 104cel/ml. The mortality rate was registered at 12, 24 and 48 hours and the colony forming units (CFU) in NBTA agar in the same intervals of time. The data were analyzed by variance analysis and mean comparison by Duncan test. Biochemical and enzymatic tests were positive for the genus Xenorhabdus. The results showed that the isolates UNPX04, UNPX15 from agricultural soils of Florida -Risaralda and Llano Bajo- Valle del Cauca respectively, caused 100% of mortality at 12 and 24 hours in contrast with seven isolations that caused only 70% of mortality.
- PublicaciónAcceso abiertoEvaluación de la patogenicidad y virulencia de aislados de Beauveria sp. En el control de Pseudacysta perseae (Heid), inductora de pestalotiopsis en palma aceitera (Elaeis guineensis Jacq) en la region caribe de Nicaragua.(Bucaramanga : Universidad de Santander, 2019, 2019-12-16) Rueda Cediel, Sergio David; Guerra-Sierra, Beatriz Elena; Muñoz Cabezas, Orlando Arturo; Caicedo, Ana MilenaThe oil palm is the most profitable oilseed plant in the agribusiness, because of the characteristics of its cultivation it is attacked by pests that generate or induce different diseases, one of them is pestalotiopsis, a disease of great economic impact, generates losses of up to 40% in production. In Nicaragua, the disease-inducing insect is Pseudacysta perseae, its control proposes biological control because it reduces the contamination presented by using chemical insecticides. Therefore, the purpose of the work was to isolate fungi from P. perseae corpses, for the identification, selection and evaluation of their pathogenic and virulent capacity on P. perseae adults. For this, the bed bug was raised in pre-nursery palms, which were infested with P. perseae., Fungal inoculums of the three isolates were prepared at different concentrations between 1.9x107 to 4.2x107 conidia / mL. For virulence and pathogenicity tests, six treatments, belonging to the three recovered microorganisms, a mixed treatment (equal mixing of the inoculums of the three isolates) were evaluated, to know the overall behavior of the isolates, negative control (water + tween 80 to 0.1%) and finally positive control (Hirsutella sp) taken into account for this investigation due to its entomopathogenic characteristic, provided by Dr. Beatriz Guerra, four repetitions were performed, sprinkling the inoculum on the palm leaflet applying 1.3 mL and concentration between 1.9x107 to 4.2x107 conidia / mL. Three times 24, 48 and 72 hours were evaluated. Finally, it was concluded that treatments number two (Beauveria sp) and number four (mixed treatment) were the most virulent with a mortality percentage of 70.8% and 69.5% respectively at 48 hours of evaluation. Finally, all the treatments evaluated have pathogenicity after 72 hours of the evaluation.
- PublicaciónAcceso abiertoEvaluación de la Susceptibilidad de Diaphorina citri Kuwayama Insecto Vector del HLB Frente a Cepas Fúngicas con Potencial Entomopatógeno en Condiciones in vitro(Universidad de Santander, 2022-11-25) Gomez-Hurtado, Karen Dayanna; Ortiz-Meneses, Fredy Alejandro; Guerra-Sierra, Beatriz Elena; Chacin-Zambrano,Christian Andrei; Antolinez-Delgado, Carlos Andres; MICROBIOTAEl estudio tuvo como objetivo evaluar la susceptibilidad de Diaphorina citri Kuwayama insecto vector del HLB frente a cepas fúngicas con potencial entomopatógeno en condiciones in vitro En el primer lugar se identificó a nivel de morfoespecie cepas fúngicas con potencial entomopatógeno perteneciente a la Colección Biología UDES (CBUDES). Mediante la descripción macroscópica obtenida en medio PDA y microscópica con la técnica de cinta adhesiva y reactivo Safranina y KOH; Por otra parte, se determinó la patogenicidad de cepas de hongos con potencial entomopatógenos, en adultos de Diaphorina citri en condiciones in vitro. A través de la preparación de soluciones conidiales 1,0^107 conidios/mL de cada una de las cepas a evaluar y sometiendo los insectos a tener un contacto con las soluciones para posteriormente someterse a un foto periodo de 12 horas luz -12 horas de oscuridad y una humedad relativa del 70% obteniendo como resultado que las cepas CNA_LIBA_HFTh_Cd_04_03 (Trichoderma sp); Beauveria sp y Metarhizium sp cuentan con un porcentaje de mortalidad entre 68% a 94 %. Seguidamente se estimó la DL50 y DL90 de cepas fúngicas con potencial entomopatógeno en control de adultos de Diaphorina citri en condiciones in vitro. Mediante la selección de las dos cepas que obtuvieron mayor patogenicidad y la preparación de soluciones conidiales a concentraciones (1,0^104; 1,0^105 1,0^106 1,0^107) en donde el porcentaje mayor de virulencia la obtuvo CNA_LIBA_HFTh_Cd_04_03 (Trichoderma sp) determinándose que a una concentración de 2,6^106 conidios/mL se produce una tasa de mortalidad del 50% (DL50), y a 1,5^107 conidios/mL, muere el 90% (DL90). Como citar este documento: Gómez Hurtado, K.D. (2022). Evaluación de la Susceptibilidad de Diaphorina citri Kuwayama Insecto Vector del HLB Frente a Cepas Fúngicas con Potencial Entomopatógeno en Condiciones in vitro
- PublicaciónAcceso abiertoEvaluación in vitro de la capacidad antagónica de hongos endófitos aislados de moringa oleífera (l) en el control de Pestalotia Palmarum (Q).(Bucaramanga : Universidad de Santander, 2019, 2019-06-22) Montoya Sánchez, Samia Hasay; Guerra-Sierra, Beatriz ElenaPestalotiopsis, produced by the fungus Pestalotia palmarum, is the main disease that causes defoliation in oil palm crops in the tropics. This disease considerably affects the sustainability of the crops and their conventional treatment, implies damage to the environment by the pollution it generates. For this reason, the search for innovative natural solutions to this problem in the agro-industrial sector is of great importance, as an alternative to chemical treatment. The adaptability of endophytic fungi to their hosts, the ecological benefits they provide and the various antagonistic mechanisms they have against pest control, make them a good alternative. In this work, the antagonistic capacity of the endophyte fungi isolated from Moringa oleifera was evaluated in the control of Pestalotia palmarum, making use of methods of isolation, identification and evaluation of the antagonism in conjunction with statistical analysis tools, which allowed determining if some of endophytic fungi, could mean an alternative for the biocontrol of Pestaloptiosis. The potential of 21 endophytic fungal strains obtained from healthy tissue was determined as candidates for the biological control of P. palmarum. Of these isolates, eight fungal strains were the most promising. Standing out among these, for its in vitro antagonistic activity against the pathogen, strain MT17, corresponding to Trichoderma sp with 87% inhibition and MH5, corresponding to Curvularia sp with 81% inhibition.
- PublicaciónAcceso abiertoFungal Endophytes of Tahiti Lime (Citrus citrus × latifolia) and Their Potential for Control of Colletotrichum acutatum J. H. Simmonds Causing Anthracnose(2021-04-01) Muñoz-Guerrero, Jaider; Guerra-Sierra, Beatriz Elena; Alvarez, Javier C.; MicrobiotaColletotrichum acutatum is one of the causal agents of anthracnose in several crops, and of post-flowering fruit drop (PFD) in citrus and key lime anthracnose (KLA). The pathogen normally attacks flowers, causing lesions only in open flowers. Under very favorable conditions, however, it can also affect flower buds and small fruits, causing complete rotting of the fruit and a premature fall, resulting in major economic crop losses. We isolated endophytic fungi from Tahiti lime to evaluate its diversity, verify its antagonistic capacity against the phytopathogen Colletotrichum acutatum C-100 in dual tests, and evaluate the ability of various endophytic agents to control flowers with induced anthracnose. 138 fungal isolates were obtained from 486 fragments of branches, leaves, and fruit; from which 15 species were identified morphologically. A higher isolation frequency was found in branches and leaves, with a normal level of diversity compared to other citrus species. Of the 15 morphospecies, 5 were trialed against C. acutatum in antagonism tests, resulting in a finding of positive inhibition. 2 endophytic fungi from the antagonism tests demonstrated high inhibition of the phytopathogen, and were thus used in in vivo tests with Tahiti lime flowers, applied in a spore solution. Spore solutions of two molecularly identified species, Xylaria adscendens, and Trichoderma atroviride, reduced the lesions caused by the phytopathogen in these in vivo tests. The finding that these endophytes react antagonistically against C. acutatum may make them good candidates for further biological control research in an agroindustry that requires environmental sustainability.
- PublicaciónAcceso abiertoMycorrhizal science outreach: Scope of action and available resources in the face of global change(2021-07-07) Silva-Flores, Patricia; Argüelles-Moyao, Andrés; Aguilar-Paredes, Ana; Simões Calaça, Francisco Junior; Duchicela, Jessica; Fernández, Natalia; Furtado, Ariadne N. M.; Guerra-Sierra, Beatriz Elena; Lovera, Milagros; Marín, César; Neves, Maria Alice; Pezzani, Fabiana; Rinaldi, Andrea C.; Rojas, Krystel; Vasco-Palacios, Aida Marcela; MicrobiotaSocietal Impact StatementMycorrhizal associations are acknowledged as key components of global ecosystem functioning. This is especially relevant in the context of global change, since they contribute to the amelioration of adverse soil conditions and play crucial roles in ag-riculture. Generally speaking, the lay public is uninformed on the importance of myc-orrhizal fungi and symbiosis to our planet. Therefore, mycorrhizal scientific outreach activities are of paramount importance in order to bridge the aforementioned gap. We think that informing people about the benefits of mycorrhizal fungi and symbiosis in the face of global change, will raise general awareness of relevant research and aid conservation efforts.SummaryScience outreach has become a particularly important duty in shortening the knowledge gap between scientists and the public, in order to strengthen societal decision- making power in the global change crisis. Mycorrhizal fungi and mycor-rhizal symbioses are key components of terrestrial ecosystems that contribute significantly to endure and reduce certain negative global change effects. Their importance has been gaining recognition in academic circles, but not among the general public. The aim of this article is to encourage as many mycorrhizal fungi re-searchers around the world as possible to build, through science outreach, a bridge between their scientific work and public interest. To this end, we conducted a re-view and discussed the relationship between global change and the mycorrhizal symbiosis. We highlight potential audiences, tools, resources, activities, outreach models, pros and cons, as well as the quantification potential for the outreach ac-tivities success. We extend an invitation to all mycorrhizologists around the world to contribute with mycorrhizal outreach material. Contributions will become avail-able on the South American Mycorrhizal Research Network website for individuals or organizations interested in starting or innovating in mycorrhizal science out-reach activities. Finally, the hashtag #mycorrhizalscienceoutreach is proposed to be used whenever a mycorrhizal fungi- related science outreach activity is shared in social media.
- PublicaciónAcceso abiertoOntogenia e histoquímica de los esporangios y escamas receptaculares del helecho epífito Pleopeltis macrocarpa (Polypodiaceae)(2019-12-05) Rincon-Baron, Edgar Javier; Guerra-Sierra, Beatriz Elena; Restrepo Zuluaga, David Esteban; Espinosa-Matías, Silvia; MicrobiotaOntogeny and histochemistry of sporangia and receptacle scales of the epiphytic fern Pleopeltis macrocarpa (Polypodiaceae).Introduction: The ontogeny of sporangia and furthermore the struc-ture and function of the receptacle scales showed by the sori of some fern species are topics scarcely represented in the scientific literature. Objectives: To describe and analyze the ontogeny of sporangia and receptacle scales of Pleopeltis macrocarpa. Methods: During March and April of 2017, fertile fronds of P. macrocarpa were col-lected from tree stems located in the plant nursery “El Edén de las flores”, municipality of Rionegro, Antioquia, Colombia. The samples were fixed and processed according to the standard protocols for embedding and sec-tioning in paraffin and resin. Sections obtained in resin (0.5 μm) were stained with Toluidine blue. The additional descriptions of the anatomy and histochemistry required specific reagents, applied for the determination of pri-mary walls, secondary walls, nuclei, lignin, polyphenols, polysaccharides, pectic substances and cellulose. The observations and photographic records were performed by photonic and epifluorescence microscopy. For the scanning electron microscopy (SEM) technique, the sori were dehydrated with 2,2- Dimethoxypropane, dried to critical point and coated with gold. Results: The sori are superficial, vascularized and have mixed development, covered by receptacle scales that detach as the sporangia reaches maturity. The leptosporangiate type sporan-gium have long stalks of primary walls, the annulus of the sporangia shows secondary walls with “U” shaped thickenings rich in lignin. The epidermal cells of the receptacle originate the sporangia and receptacle scales. The mitotic division events of these two structures are initially similar, but then diverge for the reproductive and vegetative differentiation of these two organs. Meiosis is simultaneous and the spore tetrads are arranged in a decussate or tetragonal shape. The cellular tapetum is initially unstratified but becomes bistratified by mitotic division. The inner layer of the tapetum cells break originating a plasmodial tapetum. During the sporoderm development, the first structure formed is the exospore, composed of sporopolenin, followed by the endospore composed of cellulose, pectin and carboxilated polysaccharides, and finally the perispore. The histochemistry and epifluorescence results indicate that both the sporangia and immature receptacle scales have cell walls of cellulosic. These structures as well as those of the sporangium wall cells maintain its composition during matu-ration. Whereas, the epidermal wall cells of the shields from the mature receptacle scales are characterized by thickened cuticle. The polyphenols are present during all the development stages of the sporangia and receptacle scales. Starch is abundant in the early stages of development of the receptacle cells and sporangial primordia. Conclusions: The ontogeny of the sporangia of P. macrocarpa is similar to the described for leptosporangiate ferns. The receptacle scales are mainly protective structures, its morphology and cell wall composition prevent desiccation or humidity loss of the sporangia during the labile stages of development. These results agree with the protective function attributed to the peltated pluricellular scales present in the vegetative structures of drought tolerant species of ferns and angiosperms.