scholarly journals Biocontrol of Stemphylium vesicarium and Pleospora allii on Pear by Bacillus subtilis and Trichoderma spp.: Preventative and Curative Effects on Inoculum Production

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1455
Author(s):  
Concepció Moragrega ◽  
Alba Carmona ◽  
Isidre Llorente
Keyword(s):  
Bacillus Subtilis ◽  
Field Trials ◽  
Trichoderma Spp ◽  
Vegetative Period ◽  
Stemphylium Vesicarium ◽  
Inoculum Production ◽  
Preventative Strategy ◽  
Pleospora Allii ◽  
Pathogen Colonization ◽  
Different Strains

Trials under controlled and field conditions were conducted to establish the effect of strategies of application of biological control agents (BCAs) in the reduction of Stemphylium vesicarium and Pleospora allii inoculum production on pear leaf debris. Six BCAs based on different strains of Trichoderma spp. (Tr1, Tr2) and Bacillus subtilis (Bs1, Bs2, Bs3 and Bs4) were evaluated. Two strategies were tested in controlled experiments: application before (preventative strategy) or after (curative strategy) pear leaf debris colonization by S. vesicarium, evaluating the growth inhibition and sporulation of S. vesicarium and the pseudothecia production of P. allii. When the BCAs were applied preventatively, the efficacy of treatments based on B. subtilis was higher than those based on Trichoderma spp. in controlling the pathogen colonization, but that of controlling the inoculum production of S. vesicarium and P. allii was similar. However, when the BCAs were applied curatively, Trichoderma based products were more effective. In field trials, Trichoderma spp. Tr1 and B. subtlilis Bs1 produced a consistent 45–50% decrease in the number of S. vesicarium conidia trapped compared to the non-treated control. We conclude that Bacillus subtilis Bs1 and Trichoderma spp. Tr1 and Tr2 can be expected to reduce fungal inoculum during the pear vegetative period by at least 45–50%. Additionally, Trichoderma spp. Tr1 and Tr2 have the potential to reduce the fungal overwintering inoculum by 80% to 90%.

scholarly journals Infection Potential of Pleospora allii and Evaluation of Methods for Reduction of the Overwintering Inoculum of Brown Spot of Pear

Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1511-1516 ◽  
Author(s):  
Isidre Llorente ◽  
Albert Vilardell ◽  
Emilio Montesinos
Keyword(s):  
Biological Control ◽  
Brown Spot ◽  
Control Methods ◽  
Optimum Temperature ◽  
Chemical Methods ◽  
Stemphylium Vesicarium ◽  
Mechanical Methods ◽  
Pleospora Allii ◽  
Evaluation Of Methods

The capacity for germination and pathogenicity to pear leaves of ascospores of Pleospora allii, the teleomorph of Stemphylium vesicarium, causal agent of brown spot of pear, were studied in vitro. Most ascospores germinated within 1 h at temperatures between 15 and 20°C, and the optimum temperature for germination was 18.9°C. Infections developed on wounded and non-wounded detached pear leaves, but were more frequent on wounded leaves. The minimum infective dose was one ascospore per wound. Biological, chemical, and mechanical methods for decreasing overwintering inoculum of P. allii were evaluated. Ascospores were discharged from March to May, depending on the orchard and year. Leaf shredding or removal were the most effective methods of reducing overwintering inoculum. Biological control methods based on application of Thichodermasp. formulations were partially effective. Chemical methods based on copper and urea treatments were ineffective.

scholarly journals Uso de microorganismos nativos como promotores de crecimiento y supresores de patógenos en el cultivo de la papa en Bolivia

2016 ◽  
Vol 17 (1) ◽  
pp. 74-96 ◽  
Author(s):  
P. Mamani-Rojas ◽  
J. Limachi-Villalba ◽  
N. Ortuño-Castro
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Amyloliquefaciens ◽  
Trichoderma Spp

En tres campañas consecutivas (2007 a 2010), en la comunidad de Candelaria del municipio de Colomi, departamento de Cochabamba, se evaluó el efecto de microorganismos benéficos en la productividad y el control de enfermedades de suelo que afectan la calidad de las papas nativa como Helminthosporiun solani (mancha plateada). El primer año se evaluó a los microrganismos Trichoderma spp, Bacillus amyloliquefaciens, Bacillus subtilis aplicados en diferentes dosis. El segundo año se seleccionó al mejor de los tres para optimizar su dosis e identificar su mejor formulación. El tercer año fue para confirmar los resultados del segundo año y paralelamente se evaluó su forma de aplicación. Se determinó que Trichoderma tiene un efecto significativo sobre el rendimiento de papa nativa, ssp andigena debido a su efecto sobre el número de tallos y la cobertura foliar y no así B. amyloliquefaciens y B. subtilis. Estos tres microorganismos lograron reducir el efecto de H. solani, pero Trichoderma lo hizo en mayor magnitud. El segundo y tercer año, Trichoderma spp. confirmó su efecto favorable sobre el rendimiento y en la reducción de la enfermedad. En relación a la forma de aplicación de Trichoderma, se determinó que su aplicación a surco abierto y sobre la gallinaza, tuvo un mayor efecto en el rendimiento que su aplicación previa a la gallinaza antes de la siembra o su aplicación solo a la semilla.Aceptado para publicación: Junio 19, 2012

Biotechnology and Environmental applications of Trichoderma spp.

2021 ◽  
pp. 149-157
Author(s):  
Waill A. Elkhateeb ◽  
Marwa O. Elnahas ◽  
Ghoson M. Daba ◽  
Abdel-Nasser A. Zohri
Keyword(s):  
Biological Control ◽  
Agricultural Soils ◽  
Hydrolytic Enzymes ◽  
Biological Control Agents ◽  
Growth Promoters ◽  
Trichoderma Spp ◽  
Trichoderma Species ◽  
Plant Growth Promoters ◽  
Different Strains ◽  
Soil Borne Fungi

The genus Trichoderma is multicultural soil-borne fungi found in different ecosystems. They are highly successful colonizers of their habitats. Genus Trichoderma is capable of dealing with various environments such as compost, agricultural soils, rhizosphere, and waste material. Therefore, different strains of Trichoderma have been applied in agriculture, bioremediation, waste management, and biotechnology. Many Trichoderma species act as biological control agents and plant growth promoters. Additionally, the genus Trichoderma is a new fungal source for the production of cyclosporin A as well as various hydrolytic enzymes with industrial importance.

Biocontrol de Damping off y promoción del crecimiento vegetativo en plantas de Capsicum chinense (Jacq) con Trichoderma spp.

2019 ◽  
Vol 10 (3) ◽  
pp. 471-483
Author(s):  
Edgar Javier Larios Larios ◽  
José de Jesús Wilmer Valdovinos Nava ◽  
Wilberth Chan Cupul ◽  
Felipe Alejandro García López ◽  
Gilberto Manzo Sánchez ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Trichoderma Harzianum ◽  
Capsicum Chinense ◽  
Damping Off ◽  
Trichoderma Spp ◽  
Trichoderma Sp ◽  
Chichen Itza

El objetivo del estudio fue determinar la efectividad de Trichoderma spp. en la reducción de la incidencia del Damping off y promoción del crecimiento vegetativo de plantas de Capsicum chinense (Jacq.) var. “Chichen Itza”. Se evaluó la aplicación foliar, a través de un diseño completo al azar, de dos cepas nativas de Trichoderma sp. (SP6 y Clombta), la co-aplicación de ambas, un producto comercial (Tri-HB®: Trichoderma harzianum y Bacillus subtilis) y un fungicida químico (Captan®). Durante el periodo de estudio, las plantas tratadas con Trichoderma sp. Clombta y con la co-inoculación de Trichoderma sp. Clombta + Trichoderma sp. SP6 no mostraron síntomas de Damping off. Por el contrario, plantas tratadas con Captan® y Tri-HB® mostraron los porcentajes de incidencia acumulada más alta con 5 y 4.5%, respectivamente. Asimismo, a los 28 días después de la germinación, plantas tratadas con Trichoderma sp. Clombta presentaron una mayor altura (11 cm), diámetro de tallo (2.6 mm), biomasa aérea (fresca= 0.8 g planta-1 y seca= 0.13 g planta-1) y volumen radicular (fresca= 0.13 g planta-1 y seca= 0.04 g planta-1), en comparación al resto de los tratamientos evaluados. Para la formación de hojas (9.1 hojas planta-1), área foliar (10.2 cm2) e índice de clorofila (Clombta= 209.9) la aplicación de Trichoderma sp. Clombta destacó de nuevo con los valores más altos (p< 0.05), respecto a las aplicaciones de Captan® y Tri-HB®. De acuerdo a los resultados obtenidos, se determinó que la cepa de Trichoderma sp. Clombta a concentración de 1x1013 conidios mL-1 resultó efectiva para el manejo del Damping off y promoción del crecimiento vegetativo de plantas de C. chinense var. “Chichen Itza”.

scholarly journals Chromatography of transforming deoxyribonucleic acid on methylated albumin and by gel filtration

1974 ◽  
Vol 137 (3) ◽  
pp. 543-546
Author(s):  
G. R. Barker ◽  
P. Hodges
Keyword(s):  
Molecular Weight ◽  
Bacillus Subtilis ◽  
High Molecular Weight ◽  
Deoxyribonucleic Acid ◽  
Degradation Products ◽  
Gel Filtration ◽  
Agarose Gel ◽  
Transforming Activity ◽  
Different Strains ◽  
Two Peaks

1. Native DNA from two strains of Bacillus subtilis was chromatographed by stepwise elution from MAK (methylated albumin on kieselguhr). 2. Transforming activity was confined to two out of the three main fractions, activity being distributed between the two peaks differently for DNA from the different strains. 3. Fractionation of DNA from both strains on 2% agarose gel gave two components. Approx. 75% of the material was eluted within the void volume of the column. Approx. 25% of the material consisted of degradation products of lower molecular weight. 4. Chromatography on MAK of the material of high molecular weight eluted from agarose gel gave a number of peaks differing in molecular weight, indicating that degradation of the DNA takes place during chromatography on MAK. 5. The distribution of transforming activity among the fractions from MAK suggests that degradation occurs preferentially in certain regions of the DNA.

Dry Bean and Anthracnose Development From Seeds With Varying Symptom Severity

Plant Disease ◽  
2020 ◽  
pp. PDIS-02-20-0402
Author(s):  
Jessica M. Halvorson ◽  
Robin S. Lamppa ◽  
Kristin Simons ◽  
Robert L. Conner ◽  
Julie S. Pasche
Keyword(s):  
Pathogen Detection ◽  
Seed Quality ◽  
Transmitted Disease ◽  
Weather Conditions ◽  
Field Trials ◽  
Colletotrichum Lindemuthianum ◽  
Dry Bean ◽  
Yield And Quality ◽  
Moderate Disease ◽  
Pathogen Colonization

Anthracnose, caused by the fungal pathogen Colletotrichum lindemuthianum, is a damaging seed-transmitted disease of dry beans that causes reduced seed quality and yield. Seed-to-seedling transmission of C. lindemuthianum has been documented as high as 15% in asymptomatic seeds under greenhouse conditions. Increasing pathogen colonization in seeds has been correlated with increasing anthracnose seed symptoms via quantitative PCR (qPCR), but stem colonization has not been quantified. Previous studies also have characterized seed yield and quality losses caused by planting C. lindemuthianum–infected seeds, but none evaluated the effect of growing asymptomatic seeds on disease and plant development under field conditions. A real-time qPCR assay was developed in this study and used to detect C. lindemuthianum in the stems of seedlings as early as 15 days after planting. Field trials measured the seed-to-seedling transmission of C. lindemuthianum across levels of anthracnose symptoms in seeds ranging from healthy to severely discolored. Results from these two field trials indicated that emergence and yield decreased and foliar symptoms, pathogen detection, and incidence of symptoms on progeny seeds increased as the severity of infection in planted seeds increased. In both years, planting asymptomatic seeds resulted in higher anthracnose severity than planting healthy seeds. Yield, seed weight, and incidence of symptoms on progeny seeds were not higher in asymptomatic seeds than in healthy seeds in 2014, when moderate disease pressure was observed. However, these factors were significantly different in 2015, when anthracnose severity was driven up to 75% by conducive weather conditions. This serves as a strong warning to growers that planting seed grown in a field where anthracnose was present, even if those seeds are asymptomatic, can result in yield and quality losses. Planting certified dry bean seed is always recommended.

scholarly journals Alternativas para el control de antracnosis (Colletotrichum spp) en maracuyá (Passiflora edulis)

2018 ◽  
Vol 9 (2) ◽  
pp. 2-17
Author(s):  
Fredy Alonso Niño Jiménez ◽  
Ángela Maria Mogollón Ortiz
Keyword(s):  
Bacillus Subtilis ◽  
Pseudomonas Fluorescens ◽  
Bacillus Megaterium ◽  
Trichoderma Spp ◽  
Passiflora Edulis ◽  
Colletotrichum Spp

La antracnosis en el maracuyá (Passiflora edulis) es uno de los problemas más limitantes en las zonas tropicales de Colombia causante de considerables pérdidas económicas. Este experimento fue realizado bajo condiciones de campo en un cultivo que estaba afectado por Colletotrichum spp (antracnosis) en un 50%. Con los resultados se demostró que existen alternativas diferentes al manejo químico convencional que reducen la dependencia de agroquímicos, con menor impacto negativo sobre el medio ambiente. Los ocho tratamientos evaluados para el control de antracnosis incluyeron productos biológicos y preparados con minerales, y fueron los siguientes: T1, Trichoderma spp (TR); T2, fosfito de potasio (FP); T3, caldo sulfocalcico (CS); T4, bacterias promotoras de crecimiento Bacillus megaterium, Bacillus subtilis, licheniformes, Azobacter chroococcum y Pseudomonas fluorescens (BPC); T5, caldo bordelés (CB); T6, mezcla de: BPC, TR, CS y FP; T7, control químico con un producto que contiene N-(triclorometiltio) ciclohex-4-eno-1,2-dicarboximida (CQ) y T8, testigo absoluto (TA), los cuales fueron aplicados cada 15 días, una vez iniciada la floración. Se midió el porcentaje de incidencia, teniendo en cuenta ramas, hojas y botones que manifestaron la sintomatología la enfermedad. Se estableció un diseño experimental completamente al azar con tres repeticiones para cada periodo de floración, para lo cual se seleccionaron tres ramas; se aplicó un análisis de varianza y posteriormente prueba Tukey. Durante el tiempo de evaluación se presentaron dos periodos de floración en el cultivo de maracuyá, se destacó un mayor un control de la enfermedad con CB y FP con 55.1 y 56.2% de incidencia respectivamente, valores significativamente diferentes (P<0.05) a los demás tratamientos; en tercer lugar, se destacó TR con 61.8%, es de anotar que estos tres tratamientos lograron un mejor efecto que el control químico (67.6%). En general, el porcentaje de incidencia de antracnosis fue reducido con la aplicación de los tratamientos que incluyeron inductores de resistencia como fosfito de potasio, caldo Bordelés y Trichoderma spp, cuyo comportamiento fue similar o incluso mejor que el control químico. Por su bajo costo el caldo Bordelés constituye la mejor alternativa efectiva para disminuir la incidencia de este patógeno causante de pérdidas económicas en los cultivos de maracuyá.

scholarly journals CSF, a Species-Specific Extracellular Signaling Peptide for Communication among Strains of Bacillus subtilis and Bacillus mojavensis

2008 ◽  
Vol 190 (11) ◽  
pp. 4095-4099 ◽  
Author(s):  
Mridula Pottathil ◽  
April Jung ◽  
Beth A. Lazazzera
Keyword(s):  
Bacillus Subtilis ◽  
Mediated Communication ◽  
Signaling Molecule ◽  
Bacillus Mojavensis ◽  
Extracellular Signaling ◽  
Signaling Peptides ◽  
Specific Variation ◽  
Different Strains ◽  
Species Specific

ABSTRACT ComX and CSF are Bacillus subtilis extracellular signaling peptides. Many different strains of B. subtilis do not communicate due to strain-specific variation of ComX. We demonstrate that CSF is a species-specific signaling molecule that partially compensates for the lack of ComX-mediated communication between different strains of B. subtilis.

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