scholarly journals Biological control of black pod disease of cocoa (Theobroma cacao L.) with Bacillus amyloliquefaciens, Aspergillus sp. and Penicillium sp. in vitro and in the field

2020 ◽  
Vol 12 (2) ◽  
pp. 52-63
Author(s):  
Larbi-Koranteng Stephen ◽  
Tuyee Awuah Richard ◽  
Kankam Fredrick
2012 ◽  
Vol 10 (3) ◽  
pp. 254-257
Author(s):  
Erwin Aragon ◽  
Claudia Rivera ◽  
Helena Korpelainen ◽  
Aldo Rojas ◽  
Paula Elomaa ◽  
...  

A total of 60 farmers' cacao accessions (Theobroma cacao L.) from Nicaragua were investigated using microsatellite markers to reveal their genetic composition and to identify potentially resistant genotypes against the black pod disease caused by Phytophthora palmivora. These accessions were compared with 21 breeders' accessions maintained locally, two Criollo accessions from Costa Rica and two accessions from Ecuador. The analyses showed a low level of differentiation among groups of farmers' accessions (FST = 0.06) and that six Nicaraguan accessions were genetically closely related to the two Criollo accessions used as a reference. In addition, seven distinct genotypes were found to have allelic composition that may indicate linkage to resistance alleles, thus being potential parental lines in future breeding programmes.


FLORESTA ◽  
2013 ◽  
Vol 43 (1) ◽  
pp. 145 ◽  
Author(s):  
José Antonio Sbravatti Junior ◽  
Celso Garcia Auer ◽  
Ida Chapaval Pimentel ◽  
Álvaro Figueredo dos Santos ◽  
Bruno Schultz

   O Eucalyptus benthamii é uma das principais espécies de eucalipto plantadas na região Sul do Brasil, por sua resistência a geadas e por seu uso na produção florestal de madeira para fins energéticos. Na produção de mudas, uma das principais doenças ocorrentes em viveiros é o mofo-cinzento, causado pelo fungo Botrytis cinerea. Uma das alternativas para o controle dessa doença é o controle biológico com fungos endofíticos, os quais podem competir com os patógenos foliares de mudas de eucalipto. O objetivo deste trabalho foi isolar os fungos endofíticos provenientes de mudas de E. benthamii, identificá-los e selecioná-los para o controle de B. cinerea. Eles foram isolados do interior de tecidos vegetais desinfectados, identificados de acordo com critérios macro e micromorfológicos e classificados a partir de testes de controle biológico in vitro. Os resultados evidenciaram o potencial antagonista dos fungos Aspergillus sp., Penicillium sp. e Trichoderma sp. Nenhum desses fungos causou lesões em mudas de E. benthamii.Palavras-chave: Mofo-cinzento; eucalipto; viveiro.AbstractIn vitro selection of endophytes for biological control of Botrytis cinerea in Eucalyptus benthamii. Eucalyptus benthamii is one of the main eucalypt species planted in Southern Brazil, due to its resistance to frost and its use in the production of forest wood for energy purposes. During the production of seedlings, the main disease occurring in forest nurseries is gray-mold caused by the fungus Botrytis cinerea. One alternative for control this disease is biological control with fungal endophytes, which can compete with the foliar pathogens of eucalypt seedlings. The objective of this study was to isolate endophytic fungi from seedlings of Eucalyptus benthamii, identify and select them for B. cinerea control. These were isolated from the interior of disinfected plant tissues, identified according to macro and micromorphological criteria, and based on tests of biological control in vitro. The results revealed the potential antagonist of Aspergillus sp., Penicillium sp. and Trichoderma sp. No fungi caused lesions in E. benthamii seedlings.Keywords: Gray-mold; eucalypt; nursery.    


2017 ◽  
Vol 43 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Raquel Amanda Villamizar-Gallardo ◽  
Oscar Orlando Ortíz-Rodriguez ◽  
Jhon Wilmer Escobar

ABSTRACT Cocoa (Theobroma cacao L.) is a tropical tree, seriously affected by fungal diseases. To control several pathogens, biological methods are prescribed since they are friendly to the environment and easy to use. The main objective of this study was to assess the biocontrol effect of two native strains, Trichoderma viride and Botryosphaeria quercum, on phytopathogens such as Phytophthora palmivora and Moniliophtora roreri, causal agents of black pod and frosty pod rot diseases, respectively. In addition, biocontrolers were faced on potential mycotoxigenic fungi such as Aspergills flavus and Fusarium solani, which are very common on cocoa. The Bio-Control Index (BCI) was calculated to determine the in vitro biocontrol effect against the four phytopathogens. Results indicated that the best biocontrol agent of phytopathogens was B. quercum, showing BCI of 82.3%, 80.7%, 63.3% and 59.7% for each tested phytopathogen, respectively. Competition for substrate was the dominant biocontrol strategy. As to the origin of strains, those coming from the Department Norte de Santander and Santander showed the highest average inhibition percentage. This study provides an initial screening to the endophytic and antagonistic potential of fungi, specifically those capable of colonizing cocoa pods and soils. Thus, these strains can be used as an efficient biological control alternative against several known phytopathogens of cocoa in the field.


2018 ◽  
Vol 54 (No. 2) ◽  
pp. 74-82
Author(s):  
Minyaka Emile ◽  
Banen Collette Vanessa Madina ◽  
Kusznierewicz Barbara ◽  
Doungous Oumar ◽  
Haouni Soungouna ◽  
...  

A new strategy to reduce the severity of black pod disease (BPD) in T. cacao plants using MgSO<sub>4</sub> nutrition was investigated. The dynamics of the tolerance to BPD of 18 susceptible T. cacao plantlets coming from the cross (♀SNK64 × ♂UPA14) was monitored during weekly (8 weeks) supply of MgSO<sub>4</sub> into the soil. Prior to MgSO<sub>4</sub> application, disease scores of the 18 plantlets (in six sets of three plantlets per set) were varying between 3.5 (susceptible) and 5 (highly susceptible). After MgSO<sub>4 </sub>application, a substantial decrease in disease scores was observed compared to the control. The percentage of disease tolerance gain of plantlets versus MgSO<sub>4</sub> supplied (0–2.96 g) presented a quasi-hyperbolic curve with asymptotic line corresponding to 60% (day 28) and 70% (day 56). Cysteine content was not significantly different between the six triplets before MgSO<sub>4 </sub>nutrition. On days 28 and 56 of MgSO<sub>4</sub> supplementation, cysteine content presented a pattern similar to the tolerance gain of plantlet sets. The monitoring of glutathione content versus MgSO<sub>4</sub> supplementation (compared to day 0) showed sigmoid (day 28) and hyperbolic (day 56) curves which were associated with defined mathematical laws determined by MALAB software. Negative and highly significant correlations were observed between disease scores, cysteine and glutathione contents in leaves while positive and highly significant correlations were observed between cysteine and glutathione contents in leaves. These data might mean that MgSO<sub>4</sub> nutrition significantly improved the tolerance of T. cacao. The mechanism of tolerance improvement might be associated with the synthesis of sulphur-containing compounds (cysteine and glutathione) which might be directly or indirectly used by T. cacao against P. megakarya.


2019 ◽  
Vol 10 (4) ◽  
pp. 779-788
Author(s):  
Aidé González Ruiz ◽  
Abiel Sánchez Arizpe ◽  
Yisa Maria Ochoa Fuentes ◽  
Ma. Elizabeth Galindo Cepeda ◽  
Raúl Rodríguez Guerra ◽  
...  

  Nodulosporium es un hongo ampliamente distribuido y que se encuentra en zonas tropicales y se ha reportado como fitopatógeno ocasionando muerte descendente, pudriciones y resinosis, también se le considera como un potencial agente de control biológico de otros hongos y oomicetos. El estado teleomorfo se encuentra en estado solitario y en racimos, y se ha reportado como endófito, saprofito o fitopatógeno débil. La variedad criolla de cacao Theobroma cacao, es de gran relevancia ecológica, económica y cultural en el estado de Chiapas; sin embargo, presenta alta susceptibilidad a enfermedades a diferencia de otras variedades importantes, afectando la calidad y producción. En Villa de Comaltitlán Chiapas se observaron frutos de cacao con características típicas de síntomas de pudrición. El objetivo fue identificar los hongos asociados a frutos de cacao enfermos con síntomas de pudrición. Se identificaron morfológicamente los hongos Aspergillus sp., Penicillium sp., Rhizopus sp., Trichoderma sp., y Nodulosporium sp. Se informa por primera ocasión la presencia de Nodulosporium sp., en frutos de cacao con síntomas de pudrición de Villa de Comaltitlán, Chiapas, México. Se describe las características morfológicas y morfométricas de Nodulosporium sp. e Hypoxylon sp., y su identificación molecular. Se confirmó la patogenicidad de Nodulosporium sp., en follaje del cultivo causando clorosis y deshidratación de la hoja, y se recuperó en forma de picnidios y micelio con conidios, correspondiendo a su teleomorfo, identificado como Hypoxylon morfológica y molecularmente con los oligonucleótidos ITS4-ITS5.


Sign in / Sign up

Export Citation Format

Share Document