Search Results (15)

Moniliophthora roreri (MR, frosty pod rot) and M. perniciosa (MP, witches’ broom disease) pose critical threats to cacao production in Latin America. This study explores the biocontrol potential of Trichoderma spp. strains against these pathogens through exploratory analysis of mycoparasitism, chitinolytic activity, and volatile organic compound (VOC) production. Dual-culture assays revealed species-specific antagonism, but C2A/C4B showed a dual-pathogen efficacy (>93% of Monioliopthora inhibition). Chitinase activity revealed C4A/C1 strains as exceptional producers (72 mg/mL NAGA vs. MR and 94 mg/mL vs. MP, respectively). GC-MS analysis identified pathogen-modulated VOC dynamics: hexadecanoic acid dominated in 80% Trichoderma solo-cultures (up to 26.65% peak area in C3B). MP showed 18.4-fold higher abundance of hexadecanoic acid than MR (0.23%). In 90% of dual-culture with MR and MP, HDA was detected as the most abundant. Functional specialization was evident. C4A and C1 prioritized chitinase production growing on MR and MP cell walls (respectively), whereas C9 excelled in antifungal hexadecanoic acid synthesis in confrontation with both pathogens. Complementary strengths among strains—enzymatic activity in C4A/C4B versus volatile-mediated inhibition in C9—suggest niche partitioning, supporting a consortium-based approach for robust biocontrol. This study provides preliminary evidence for the biocontrol potential of several Trichoderma strains, showing possible complementary modes of action. Full article

In this study, the antifungal potential of chemical constituents of Piper ceanothifolium Kunth was determined against three phytopathogenic fungi associated with the cocoa crop. The methodology included the phytochemical study of the inflorescences of P. ceanothifolium, the synthesis of a chroman-4-one type derivative and the evaluation of the antifungal activity against Moniliophthora roreri, Fusarium solani, and Lasiodiplodia theobromae. The phytochemical study led to the isolation and identification of two new hydroquinones (1 and 5), together with three known compounds (hydroquinones 2 and 3, and chromene 4). The synthesis of a new chromone 6 obtained from 2 through an oxa-Michael type intramolecular cyclization is also reported. All compounds showed strong antifungal activity, with 6 (IC₅₀ of 16.9 µM) standing out for its action against F. solani, while prenylated hydroquinones 1 (30.4 µM) and 2 (60.0 µM) were the most active against M. roreri and L. theobromae, respectively. The results of this research represent the first report of the chemical composition and antifungal properties for P. ceanotifolium, suggesting its potential use as a control method against M. roreri, F. solani, and L. theobromae. Full article

Cocoa, a crop with great socioeconomic impact in Ecuador, faces continuous challenges that undermine the quality and yield of the crops. Moniliasis, a phytosanitary problem that is difficult to control, is the main limiting factor in cocoa production. This disease is caused by the phytopathogen Moniliophthora roreri, which causes premature maturation and necrosis of the ears. In this study, 50 strains of Trichoderma spp. in two-culture media, PDA and MEA, were used to evaluate the mycelial characteristics and antagonistic capacity of the strains in individual situations and in circumstances of confrontation against the phytopathogens Moniliophthora roreri (MRCP) and Moniliophtora roreri (MMCA). The data from the parameters obtained in the in vitro experimental practice were subjected to the multivariate PCA biplot method; the results indicated that five strains exhibited a notable antagonism capacity against the two specific strains of M. roreri: strain E22 grown on PDA medium, and the other four (E25, E29, E30, E39) cultivated on MEA medium. The open field trial showed that all treatments based on Trichoderma spp. improved productive performance compared to control plantations to which no biopreparation was applied. Significant differences (p < 0.05) were reported for all treatments. The efficiency of the biopreparations ranged between 51.26% and 72.46% with yields of 677.86 kg/ha to 976.90 kg/ha, respectively. The Trichoderma strain E29 showed the greatest potential for the biological control of M. roreri under field conditions. The findings validate the effect of diversified Trichoderma biopreparations in the biological control of moniliasis, providing concrete data on the efficacy of the biopreparation under real cultivation conditions and supporting its practical viability. Full article

The species Zanthoxylum caribaeum belongs to the Rutaceae family, from which several chemical nuclei are known, including alkaloids and coumarins. In addition, its essential oil has been characterized, showing differences in composition and various antimicrobial activities. In the present study, the essential oil of Z. caribaeum collected in the department of Tolima, central Colombia, was characterized by gas chromatography with mass selective detector (GC-MS). The essential oil showed a composition of about 43 compounds (including major and minor), whose main components, according to their abundance, are the following: germacrene D (228.0 ± 1.6 mg/g EO), (E)-β-farnesene (128.0 ± 1.5 mg/g EO), β-elemene (116.0 ± 1.6 mg/g EO) and (E)-nerolidol (74.0 ± 2.2 mg/g EO). This oil was tested against microorganisms that affect cocoa production in Colombia and in tropical countries where the production of this commodity is very important for the economy. The antifungal tests were performed on the fungal species Moniliophthora roreri and showed promising and significant activity, inhibiting growth by more than 95% at concentrations of 50 µL/mL and 100 µL/mL. This remarkable antifungal activity could be due to the presence of major and minor compounds that synergistically enhance the activity. Full article

In Mexico, cacao production is endangered by pathogenic fungi, such as Phytophthora spp. and Moniliophthora rorei, that cause black pod rot and moniliasis, respectively. In this study the biocontrol agent Paenibacillus sp. NMA1017 was tested in cacao fields against the previous diseases. The treatments applied were shade management, inoculation of the bacterial strain with or without an adherent, and use of chemical control. The statistical analysis showed that the incidence of black pod rot in tagged cacao trees diminished when the bacterium was applied (reduction of 44.24 to 19.11%). The same result was observed with moniliasis when the pods were tagged (reduction of 66.6 to 27%). The use of Paenibacillus sp. NMA1017 with an integrated management might be a solution to cacao diseases and to having a sustainable production of cacao in Mexico. Full article

Ecuador is one of the major cocoa producers worldwide, but its productivity has lately been affected by diseases. Endophytic biocontrol agents have been used to minimize pathogenic effects; however, compounds produced by endophytes are minimally understood. This work presents the chemical characterization of the Trichoderma species extracts that proved inhibition against cocoa pathogens. Solid–liquid extraction was performed as a partitioning method using medium with the fungal mycelia of Trichoderma reesei (C2A), Trichoderma sp. (C3A), Trichoderma harzianum (C4A), and Trichoderma spirale (C10) in ethyl acetate individually. The extract of T. spirale (C10) exhibited the growth inhibition (32.97–47.02%) of Moniliophthora perniciosa at 10 µg/mL, while a slight stimulation of Moniliophthora roreri was shown by the extracts of T. reesei (C2A) and T. harzianum (C4A) at higher concentrations. The inhibitory activity could be related to alkaloids, lactones, quinones, flavonoids, triterpenes, and sterols, as indicated by chemical screening and antifungal compounds, such as widdrol, β-caryophyllene, tyrosol, butyl isobutyrate, sorbic acid, palmitic acid, palmitelaidic acid, linoleic acid, and oleic acid, which were identified by gas chromatography–mass spectrometry (GC-MS). The results showed that the extracts, particularly T. spirale (C10), have the potential as biocontrol agents against witches’ broom disease; however, further studies are needed to confirm their effectiveness. Full article

Cocoa is the main crop in Ecuador’s agricultural sector and is the most important to the country’s economy. This crop is mainly threatened by moniliasis caused by Moniliophthora roreri and Moniliophthora perniciosa. Monialisis is a disease that causes the watery rot of cocoa beans, causing serious yield losses at crop harvest and great economic losses. In this research, we used 50 Trichoderma spp. cultivated in two culture media, PDA and MEA, to demonstrate mycelial growth and antagonistic capacity against two cacao-crop pathogens: M. roreri and M. perniciosa. Multivariate methods, namely a PCA biplot and a GGE biplot, indicated that four strains of Trichoderma spp. (17, 33, 42 and 44) cultivated on the PDA medium had the highest mycelial characteristic values and antagonistic capacities against Moniliophthora perniciosa. The experimental test showed that the lowest incidence of moniliasis and highest yield of cocoa occurred when using the treatments based on the Trichoderma spp. The results obtained in this study allow the use of strain 42 to control moniliasis in cocoa, avoiding economic losses. Full article

Frosty pod rot, caused by Moniliophthora roreri, is the most damaging disease of cacao in Latin America and, to better comprehend its epidemiology, we must understand its dissemination and proliferation. However, we do not know how M. roreri spores loads fluctuate in time and space due to the lack of a reliable technique to quantify M. roreri spores in the fields. Therefore, we developed a method that relies on spore traps and qPCR to detect and quantify M. roreri spore loads. This study demonstrated that the qPCR protocol can detect down to 0.025 ng of M. roreri DNA and quantify between 0.006 ng and 60 ng. Moreover, it demonstrated that qPCR protocol can detect and quantify DNA extracted from spore suspension and spore traps containing at least 2.9 × 10⁴ M. roreri spores. However, the variability of the estimates for spore samples was high. Finally, we described a spore-trap device designed to carry spore traps in the field. The qPCR protocol and spore-trap device here developed will help in the understanding of the M. roreri dissemination patterns since they can be used to assess the environmental loads of M. roreri spore in cacao fields. Full article

Citrinin (CIT) is a mycotoxin found in foods and feeds and most commonly discovered in red yeast rice, a food additive made from ordinary rice by fermentation with Monascus. Currently, no enzyme is known to be able to degrade CIT effectively. In this study, it was discovered that manganese peroxidase (MrMnP) from Moniliophthora roreri could degrade CIT. The degradation appeared to be fulfilled by a combination of direct and indirect actions of the MrMnP with the CIT. Pure CIT, at a final concentration of 10 mg/L, was completely degraded by MrMnP within 72 h. One degradation product was identified to be dihydrocitrinone. The toxicity of the CIT-degradation product decreased, as monitored by the increased survival rate of the Caco-2 cells incubated with MrMnP-treated CIT. In addition, MrMnP could degrade CIT (with a starting concentration of up to 4.6 mg/L) completely contaminated in red yeast rice. MrMnP serves as an excellent candidate enzyme for CIT detoxification. Full article

Frosty pod rot, caused by the fungus Moniliophthora roreri, is one of the most important diseases of cacao in Peru. Sustainable alternatives to control it include timely cultural practices such as pruning, and the application of biological control agents such as Trichoderma spp. We isolated 234 Trichoderma strains native to the department of Amazonas in Northern Peru from soil samples in cacao farms. These strains belong to at least eighteen species within four phylogenetic clades in the genus (Harzianum, Longibrachiatum, Hamatum, and Brevicompactum clades). We aimed to assess the in vitro biocontrol potential of these strains against M. roreri. We evaluated their mycoparasitism, antibiosis, and potential antagonism to select candidate strains for efficient biocontrol of M. roreri. We found evidence (Kruskal–Wallis test, p < 0.005) that strains belonging to the Harzianum clade tend to have higher mycoparasitism, antibiosis, and potential antagonism levels than strains in the Longibrachiatum and Hamatum clades. Additionally, this study constitutes the first report for antagonistic behavior against M. roreri for T. parareesei, T. lentiforme, T. orientale, T. asperelloides, T. inhamatum, T. zelobreve, T. afarasin, T. ghanense, T. rifaii, and T. breve. These results will be foundational for further M. roreri biocontrol studies. Full article

The fungal secondary metabolite patulin is a mycotoxin widespread in foods and beverages which poses a serious threat to human health. However, no enzyme was known to be able to degrade this mycotoxin. For the first time, we discovered that a manganese peroxidase (MrMnP) from Moniliophthora roreri can efficiently degrade patulin. The MrMnP gene was cloned into pPICZα(A) and then the recombinant plasmid was transformed into Pichia pastoris X-33. The recombinant strain produced extracellular manganese peroxidase with an activity of up to 3659.5 U/L. The manganese peroxidase MrMnP was able to rapidly degrade patulin, with hydroascladiol appearing as a main degradation product. Five mg/L of pure patulin were completely degraded within 5 h. Moreover, up to 95% of the toxin was eliminated in a simulated patulin-contaminated apple juice after 24 h. Using Escherichia coli as a model, it was demonstrated that the deconstruction of patulin led to detoxification. Collectively, these traits make MrMnP an intriguing candidate useful in enzymatic detoxification of patulin in foods and beverages. Full article

One of the main problems in the production of cacao in Ecuador is the disease caused by the fungus Moniliophthora roreri (frosty pod rot) which affects the pods. Here, we evaluate the genetic diversity of this fungus in Ecuador, and its sensitivity to the fungicide azoxystrobin. We evaluated 76 monosporic cultures from the Amazon and the Pacific coast regions. In vitro sensitivity assays tested several doses of the fungicide azoxystrobin to determine the percent of growth inhibition and the IC₅₀. Concentrations of 1 to 0.1 µg mL⁻¹ inhibited the growth of at least 91% of the isolates. Three isolates were the less sensitive (IC₅₀ = 0.0220–0.0364 µg mL⁻¹), two from Guayas (Pacific coast) and one from Sucumbíos (Amazon) provinces. However, M. roreri is highly sensitive, and it could be used in integrated management of the disease. Genetic analyses were carried out by amplifying microsatellite markers (SSR). All the genetic diversity statistics show a higher diversity in the Amazon compared to samples of the coast region; however, the molecular variance was low (F_ST = 0.11). Discriminant analysis clearly distinguishes three clusters concurrent with the provinces (Sucumbíos, Orellana and El Oro) and a group with the rest of the provinces. Minimum spanning networks shows, unexpectedly, that M. roreri from the coast were derived from at least three independent introductions from the Amazon. Findings are discussed in light of previous Pan-American genetic studies and available historical reports. Full article

In this study, the antifungal potential of chemical constituents from Piper pesaresanum and some synthesized derivatives was determined against three phytopathogenic fungi associated with the cocoa crop. The methodology included the phytochemical study on the aerial part of P. pesaresanum, the synthesis of some derivatives and the evaluation of the antifungal activity against the fungi Moniliophthora roreri, Fusarium solani and Phytophthora sp. The chemical study allowed the isolation of three benzoic acid derivatives (1–3), one dihydrochalcone (4) and a mixture of sterols (5–7). Seven derivatives (8–14) were synthesized from the main constituents, of which compounds 9, 10, 12 and 14 are reported for the first time. Benzoic acid derivatives showed strong antifungal activity against M. roreri, of which 11 (3.0 ± 0.8 µM) was the most active compound with an IC₅₀ lower compared with positive control Mancozeb^® (4.9 ± 0.4 µM). Dihydrochalcones and acid derivatives were active against F. solani and Phytophthora sp., of which 3 (32.5 ± 3.3 µM) and 4 (26.7 ± 5.3 µM) were the most active compounds, respectively. The preliminary structure–activity relationship allowed us to establish that prenylated chains and the carboxyl group are important in the antifungal activity of benzoic acid derivatives. Likewise, a positive influence of the carbonyl group on the antifungal activity for dihydrochalcones was deduced. Full article

The use of native Trichoderma strains has been proposed as a sustainable alternative to control cocoa diseases. The aim of this study was to assess indigenous Trichoderma strains from Bagua Province, Peru, with reference to their antagonistic characteristics in vitro and their potential for in vitro biocontrol against frosty pod rot (FPR) disease. A total of 199 strains were assessed for in vitro mycoparasitism, antibiosis, and potential antagonism. The effect of four strains was evaluated in vitro using epidemiological variables, yield, and efficacy at two sites (Copallín and La Peca). Significant differences (p < 0.05) were reported for all variables evaluated in vitro and in vitro. Mycoparasitism ranged from 32% to 100%, antibiosis from 33.36% to 57.92%, and potential antagonism from 42.36% to 78.64%. All strains were found to affect the in vitro-assessed parameters in addition to enhancing the productive yield. The efficiency ranged from 38.99% to 71.9% in Copallín, and 45.88% to 51.16% in La Peca. The CP24-6 strain showed the highest potential for biocontrol under field conditions when considering its effect on both sites. Full article

The production of cocoa (Theobroma cacao L.) in Colombia has a significant environmental and socioeconomic importance as a promissory crop in the post-conflict process. The department of Norte de Santander has cocoa crops that are dramatically affected by fungal pathogens causing important losses during harvest and post-harvest. Therefore, the current study focused on the determination of the incidence of diseases caused by phytopathogenic fungi in cocoa crops, and the identification of primary phytopathogenic fungi found in biological material from different farms of the region. The study was conducted in four municipalities of the department, by sampling fruits infected with frosty pod rot (FPR) and black pod rot (BPR) that presented in situ incidence ranging from 0.37 to 21.58% and from 1.75 to 35.59%, respectively. The studied hybrid materials, together with clone TSH 65, were found to be the most susceptible, while the remaining clones were more tolerant, especially CCN 51, IMC 67, and ICS95. Fifteen strains were isolated using in vitro assays and then morphologically characterized both in solid media and by microscopy. Nine of them corresponded to the pathogen Moniliophthora roreri, and other six to Phytophthora palmivora. The isolated agents showed in vitro morphological variability, as well as the ability to adapt to different environments when growing in situ. Full article