scholarly journals Actinobacterias con potencial antagónico in vitro a hongos fitopatógenos y promoción del crecimiento en plantas de chile

2019 ◽  
pp. 339-344
Author(s):  
Bertha María Sánchez-García ◽  
Juan Gabriel Ramírez-Pimentel ◽  
Luis Patricio Guevara-Acevedo ◽  
Juan Carlos Raya-Pérez ◽  
Jorge Covarrubias-Prieto ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Phytophthora Capsici

El potencial inhibitorio de tres cepas de actinobacterias (B21, B22 y B37) contra los fitopatógenos: Rhizoctonia solani, Phytophthora capsici y Fusarium oxysporum fue evaluado in vitro mediante la técnica de cultivos aperados, donde a las 72 h después de la confrontación se evaluó el porcentaje de inhibición del crecimiento radial (PICR) por las actinobacterias. Los resultados mostraron un PICR variable entre 67.54 y 93.84% dependiendo del patógeno. La cepa B22 fue la que mostro un PICR promedio de 98.73% para los tres fitopatógenos. En el escrutinio in vivo, las plantas de chile inoculadas con las actinobacterias mostraron mayor altura de la planta y mayor peso seco de los frutos con respecto al testigo, lo que sugiere que las actinobacterias promueven el crecimiento de plantas de chile.

scholarly journals Antagonismo de Saccharicola sp., contra fitopatógenos de la raíz de chile jalapeño (Capsicum annuum)

2017 ◽  
Vol 35 (2) ◽  
Author(s):  
Ana Karina Uc-Arguelles ◽  
Jesús Pérez-Moreno ◽  
Victoria Ayala-Escobar ◽  
Emma Zavaleta-Mejía
Keyword(s):  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Capsicum Annuum ◽  
Phytophthora Capsici ◽  
Para Determinar

<p>Se evaluó la capacidad antagónica de <em>Saccharicola </em>sp <em>in vitro</em> e invernadero contra <em>Phytophthora capsici</em>, <em>Fusarium oxysporum</em> y <em>Rhizoctonia solani</em>. Mediante confrontaciones duales se evaluó la reducción de crecimiento del fitopatógeno y se registró el número de días en que el antagonista invadió el micelio de los patógenos, se determinó la viabilidad del micelio invadido y la producción de propágulos del fitopatógeno. <em>Saccharicola</em> sp causó reducción de 44.8 % y 45.1 % en el crecimiento de <em>P. capsici</em> y <em>F. oxysporum</em> a los 3 días posteriores a la confrontación (dpc) y en <em>R. solani</em> 36.2 % a los 2 dpc. Para determinar su potencial micoparasítico se realizaron microcultivos. A las 72 h se observó el enrollamiento del antagonista alrededor de <em>P. capsici</em>. En <em>R. solani</em> desde las 24 h se observaron hundimientos en los sitios de contacto con el antagonista. A pesar que en condiciones <em>in vitro Saccharicola</em> sp mostró un efecto negativo contra los fitopatógenos y hubo evidencia de  micoparasitismo, en invernadero no redujo la incidencia y severidad de la enfermedad, ni promovió el crecimiento de las plantas.</p>

scholarly journals Compost Tea Induces Growth and Resistance against Rhizoctonia solani and Phytophthora capsici in Pepper

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 781
Author(s):  
Ana Isabel González-Hernández ◽  
M. Belén Suárez-Fernández ◽  
Rodrigo Pérez-Sánchez ◽  
María Ángeles Gómez-Sánchez ◽  
María Remedios Morales-Corts
Keyword(s):  
Plant Growth ◽  
Rhizoctonia Solani ◽  
Growth Parameters ◽  
Phytophthora Capsici ◽  
Nutrient Content ◽  
In Vitro Assays ◽  
Open Flower ◽  
Pepper Plants

Compost teas (CTs) are organic solutions that constitute an interesting option for sustainable agriculture. Those that come from garden waste have been applied in vitro and in vivo on pepper plants to determine its suppressive effect against both Phytophthora capsici and Rhizoctonia solani. The studied CT showed relevant content in NO3−, K2O, humic acids, and microorganisms such as aerobic bacteria, N-fixing bacteria, and actinobacteria, which play a role in plant growth and resistance. This rich abundance of microbiota in the CT induced a reduction in the relative growth rate of both P. capsici and R. solani (31.7% and 38.0%, respectively) in in vitro assays compared to control. In addition, CT-irrigated plants displayed increased growth parameters and showed the first open flower one week before those treatments without CTs, which suggests that its application advanced the crop cycle. Concerning pathogen infection, damage caused by both pathogens became more apparent with a one-week inoculation compared to a four-week inoculation, which may indicate that a microbiological and chemical balance had been reached to cope with biotic stresses. Based on these results, we conclude that CT application induces plant growth and defense in pepper plants against P. capsici and R. solani because of its relevant soluble nutrient content and microbiota richness, which provides a novel point for plant nutrition and protection in horticultural crops.

scholarly journals Fitness of Isolates of Phytophthora capsici Resistant to Mefenoxam from Squash and Pepper Fields in North Carolina

Plant Disease ◽  
2008 ◽  
Vol 92 (10) ◽  
pp. 1439-1443 ◽  
Author(s):  
Adalberto C. Café-Filho ◽  
Jean Beagle Ristaino
Keyword(s):  
North Carolina ◽  
Phytophthora Capsici ◽  
Colony Growth ◽  
Relative Fitness ◽  
In Planta ◽  
Phytophthora Blight ◽  
In Vivo Experiments ◽  
First Time

Despite the wide adoption of mefenoxam (Ridomil Gold EC) for vegetables in North Carolina, the incidence of Phytophthora blight on pepper (Capsicum annuum) and squash (Cucurbita pepo) is high. Seventy-five isolates of Phytophthora capsici were collected in five pepper and one squash field in order to assess mefenoxam sensitivity. The relative fitness of resistant and sensitive isolates was contrasted in vitro by their respective rates of colony growth and their ability to produce sporangia in unamended V8 juice agar medium. In in vivo experiments, the aggressiveness of isolates on pepper was evaluated. The frequency of resistant isolates in North Carolina populations was 63%, considerably higher than resistance levels in areas where mefenoxam is not widely adopted. Resistant isolates grew on amended media at rates >80 to 90% and >100% of the nonamended control at 100 μg ml-1 and 5 μg ml-1, respectively. Sensitive isolates did not growth at 5 or 100 μg ml-1. All isolates from three fields, including two pepper and a squash field, were resistant to mefenoxam. Populations from other fields were composed of either mixes of sensitive and resistant isolates or only sensitive isolates. Response to mefenoxam remained stable during the course of in vitro and in planta experiments. Occurrence of a mefenoxam-resistant population of P. capsici on squash is reported here for the first time in North Carolina. When measured by rate of colony growth, sporulation in vitro, or aggressiveness in planta, fitness of resistant isolates was not reduced. Mefenoxam-resistant isolates from squash were as aggressive on pepper as sensitive or resistant pepper isolates. These results suggest that mefenoxam-resistant populations of P. capsici are as virulent and fit as sensitive populations.

scholarly journals KEEFEKTIFAN FORMULA MINYAK CENGKEH DAN SERAI WANGI TERHADAP Fusarium oxysporum f.sp. vanillae PENYEBAB BUSUK BATANG VANILI

2020 ◽  
Vol 18 (4) ◽  
pp. 143
Author(s):  
MESAK TOMBE ◽  
DARMAWAN PANGERAN ◽  
TRI SAPTARI HARYANI
Keyword(s):  
Fusarium Oxysporum ◽  
Soil Microorganisms ◽  
Soil Microorganism ◽  
Stem Rot ◽  
Clove Oil ◽  
Vanilla Planifolia ◽  
Green House ◽  
Microorganism Population

<p>ABSTRAK<br />Busuk batang vanili (BBV) yang disebabkan oleh Fusarium<br />oxysporum f.sp. vanillae (Fov) merupakan patogen penting pada vanili dan<br />menyebabkan kerugian besar setiap tahunnya di Indonesia. Jumlah<br />kerugian diperkirakan sebesar 3.000 ton atau sekitar US$ 16 juta.<br />Penelitian dilaksanakan di laboratorium dan rumah kaca Kelti Hama dan<br />Penyakit, Balai Penelitian Tanaman Rempah dan Obat, Bogor pada bulan<br />Februari 2010 sampai Agustus 2010. Tujuan penelitian adalah untuk<br />mengetahui pengaruh formula dengan bahan aktif minyak cengkeh dan<br />serai wangi terhadap penyakit BBV dan dampaknya terhadap kehidupan<br />mikroorganisme tanah. Dalam pelaksanaannya, kegiatan penelitian dilaku-<br />kan dalam 3 tahap yaitu : (1) uji formula in vitro, (2) uji formula in vivo,<br />dan (3) uji dampak formula terhadap mikroorganisme tanah. Percobaan<br />tahap 1, 2, dan 3 masing-masing terdiri atas 10, 6, dan 6 perlakuan,<br />dan.masing-masing disusun menggunakan rancangan acak lengkap dengan<br />3 ulangan. Materi yang dikaji dalam penelitian ini adalah (1) formula<br />dengan bahan aktif minyak cengkeh (formula standar), (2) formula dengan<br />bahan aktif minyak cengkeh dan serai wangi (formula baru), dan (3)<br />fungisida sintetis berbahan aktif mankozeb sebagai pembanding. Hasil uji<br />in vitro menunjukkan bahwa fungisida nabati CS (minyak cengkeh + serai<br />wangi) pada ke 3 tingkatan konsentrasi (terutama konsentrasi 400 ppm)<br />memperlihatkan efektivitas yang tinggi dalam menghambat pertumbuhan<br />miselium dan produksi spora patogen Fov.F117 dibandingkan perlakuan<br />lain dan kontrol. Hasil uji in vivo menunjukkan hal yang sama bahwa<br />fungisida nabati CS memperlihatkan efektivitas yang tinggi dalam<br />menekan intensitas serangan patogen BBV, terutama pada dosis aplikasi 5<br />ml/l. Dampak perlakuan terhadap kehidupan mikroorganisme tanah (fungi<br />dan bakteri) memperlihatkan bahwa penggunaan fungisida sintetis<br />mankozeb menghambat kehidupan mikroorganisme tanah 90-100% jika<br />dibandingkan dengan kontrol. Populasi mikroorganisme tanah pada semua<br />perlakuan fungisida nabati lebih tinggi jika dibandingkan dengan fungisida<br />mankozeb. Populasi mikroorganisme pada aplikasi fungisida nabati pada<br />dosis 5 ml/l tidak berbeda nyata dengan kontrol. Penelitian ini<br />menunjukkan bahwa penggunaan fungisida nabati minyak cengkeh<br />terutama jika dikombinasikan dengan minyak serai wangi mempunyai<br />prospek untuk digunakan dalam pengendalian penyakit BBV dengan<br />interval aplikasi 3-4 minggu sekali.<br />Kata kunci : Vanilla planifolia, Fusarium oxysporum f.sp, vanillae, busuk<br />batang vanili, minyak cengkeh, minyak serai wangi</p><p>ABSTRACT<br />Vanilla stem rot (VSR) disease caused by Fusarium oxysporum f.sp.<br />vanillae (Fov) is an important disease on vanilla and causes severe loss<br />annually in Indonesia. The total annual loss in production due to the VSR<br />was estimated to be 3,000 ton or about US$ 16 million. This research was<br />carried out in the laboratory and green house of Pest and Disease of<br />Research Institute for Spices and Medicinal Crops, Bogor from February<br />2010 until August 2010. The objective of this research was to study the<br />effect of formula using active compounds of clove and citronella oils on<br />the VSR disease and its impact on the survival of soil microorganisms.<br />The research activities were conducted in three stages, namely (1) in vitro<br />formula test; (2) in vivo formula test, and (3) impact test of formula on the<br />soil microorganisms. Materials studied in this research were (1) formula<br />with active compound of clove oil (standard), (2) formula with active<br />compound of clove and citronella oils (new formula), and (3) synthetic<br />fungicide with mancozeb active ingredient as comparison. Every phase of<br />this 3 stage experiment was arranged using completely randomized design<br />with three replicates. First, second, and third phases of the experiment<br />consisted of 10, 6, and 6 treatments, respectively. In vitro test results<br />carried out in the laboratory indicated that botanical formula CS (clove and<br />citronella oils of the three concentration levels, especially on the 400 ppm)<br />showed high effectiveness on inhibiting mycelium growth and spore<br />production of Fov.F117 pathogen compared to other treatments and<br />control. In vivo test in the green house indicated the same result that<br />botanical fungicide CS (clove dan citronella oils) showed high<br />effectiveness in suppressing VSR disease infection intensity, especially on<br />5 ml/l dosage. Application of mancozeb synthetic fungicide inhibited 90 –<br />100% soil microorganism livelihood compared to control. However, the<br />soil microorganism population on all botanical fungicides was higher than<br />on mancozeb fungicide. The microorganism population on the botanical<br />fungicide of 5 ml/l dosage was not significantly different from the control<br />(natural soil with no treatment). This research indicates that aplication of<br />botanical fungicide (combination between clove and citronella oils) with<br />3 - 4 weeks interval is prospectous to control VSR disease.<br />Key words : Vanilla planifolia, Fusarium oxysporum, f.sp. vanillae,<br />vanilla stem rot, clove oil, citronella oil</p>

scholarly journals In vitro antifungal potential of plant extracts against Fusarium oxysporum, Rhizoctonia solani and Macrophomina phaseolina.

2017 ◽  
Vol 6 (9) ◽  
pp. 1676 ◽  
Author(s):  
Ramaraju Cherkupally ◽  
Srinivasa Reddy Kota ◽  
Hindumathi Amballa ◽  
Bhumi Narasimha Reddy
Keyword(s):  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Plant Extracts ◽  
Mycelial Growth ◽  
Aloe Vera ◽  
Datura Stramonium ◽  
Macrophomina Phaseolina ◽  
Calotropis Procera ◽  
Fungitoxic Effect

The antifungal activity of aqueous extracts of nine plants viz, Azadirachta indica, Parthenium hysterophorus, Momordica charantia, Allium sativum, Eucalyptus globules, Calotropis procera, Aloe vera, Beta vulgaris and Datura stramonium were assessed in vitro against Fusarium oxysporum f. sp. melongenae, Rhizoctonia solani and Macrophomina phaseolina, the soil borne phytopathogens. The assessment of fungitoxic effect was carried out by using three different concentrations i.e., 5, 10 and 20% against the test fungi, in terms of percentage of mycelial growth inhibition. The extract of A. sativum completely inhibited the mycelial growth of M. phaseolina at all the concentrations. The extracts of D. stramonium and E. globulus inhibited the mycelial growth of R. solani of 72%, and 70.7% respectively at 20% concentration, that of A. sativum, E. globulus and D. stramonium exhibited inhibition percentage of 63.3%, 61.8% and 61.1% respectively at 20% concentration on Fusarium oxysporum f. sp. melongenae. The application of plant extracts for disease management could be less expensive, easily available, non-polluting and eco-friendly.

scholarly journals Self-Inhibitory Activity of Trichoderma Soluble Metabolites and Their Antifungal Effects on Fusarium oxysporum

2020 ◽  
Vol 6 (3) ◽  
pp. 176
Author(s):  
Samuel Álvarez-García ◽  
Sara Mayo-Prieto ◽  
Santiago Gutiérrez ◽  
Pedro Antonio Casquero
Keyword(s):  
Fusarium Oxysporum ◽  
Inhibitory Activity ◽  
Inhibitory Effects ◽  
Trichoderma Spp ◽  
Macroscopic Structure ◽  
Biocontrol Activity ◽  
Microbial Strains ◽  
Phytopathogenic Microorganisms

Self-inhibitory processes are a common feature shared by different organisms. One of the main mechanisms involved in these interactions regarding microorganisms is the release of toxic diffusible substances into the environment. These metabolites can exert both antimicrobial effects against other organisms as well as self-inhibitory ones. The in vitro evaluation of these effects against other organisms has been widely used to identify potential biocontrol agents against phytopathogenic microorganisms. In the present study, we performed membrane assays to compare the self-inhibitory effects of soluble metabolites produced by several Trichoderma isolates and their antifungal activity against a phytopathogenic strain of Fusarium oxysporum. The results demonstrated that Trichoderma spp. present a high self-inhibitory activity in vitro, being affected in both their growth rate and the macroscopic structure of their colonies. These effects were highly similar to those exerted against F. oxysporum in the same conditions, showing no significant differences in most cases. Consequently, membrane assays may not be very informative by themselves to assess putative biocontrol capabilities. Therefore, different methods, or a combination of antifungal and self-inhibitory experiments, could be a better approach to evaluate the potential biocontrol activity of microbial strains in order to pre-select them for further in vivo trials.

Role of chitinase and β-1,3-glucanase activities produced by a fluorescent pseudomonad and in vitro inhibition of Phytophthora capsici and Rhizoctonia solani

2007 ◽  
Vol 53 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Naveen Kumar Arora ◽  
Min Jeong Kim ◽  
Sun Chul Kang ◽  
Dinesh Kumar Maheshwari
Keyword(s):  
Rhizoctonia Solani ◽  
Phytophthora Capsici ◽  
Phytopathogenic Fungi ◽  
Culture Technique ◽  
Dual Culture ◽  
Fluorescent Pseudomonad ◽  
Antifungal Metabolites ◽  
Fluorescent Pseudomonas

A study was conducted to investigate the possibility of involvement of chitinase and β-1,3-glucanase of an antagonistic fluorescent Pseudomonas in growth suppression of phytopathogenic fungi, Phytophthora capsici and Rhizoctonia solani . Fluorescent Pseudomonas isolates GRC3 and GRC4 were screened for their antifungal potential against phytopathogenic fungi by using dual culture technique both on solid and liquid media. The percent inhibition was calculated. Various parameters were monitored for optimization of enzyme activities by fluorescent Pseudomonas GRC3. The involvement of chitinases, β-1,3-glucanases, and antifungal metabolites of nonenzymatic nature was correlated with the inhibition of P. capsici and R. solani. The results provide evidence for antibiosis as a mechanism for antagonism. The study also confirms that multiple mechanisms are involved in suppressing phytopathogens as evidenced by the involvement of chitinase and β-1,3-glucanase in inhibition of R. solani but not P. capsici by isolate GRC3.

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