Antifungal effect from Zingiber officinale, Aloe vera and Trichoderma sp. for control of Moniliophthora roreri in Theobroma cacao in Huánuco, Peru

Theobroma cacao is the main raw material to produce chocolate, as well as for use in the food, cosmetic, and pharmaceutical industries. However, Moniliophthora roreri is one of the most destructive fungal diseases and the main limiting of cacao production worldwide. Thus, this work aimed to assess the inhibitory effect of extracts of Zingiber officinale (T1) and Aloe vera (T2), and Trichoderma harzianum + Bacillus subtillis. (T3) on Moniliophthora roreri infection in Theobroma cacao; in addition, a control (T4) was also evaluated. Each treatment was applied to six plants of cacao. Incidence of monilia infection and fruit weight were monitored every 15 days (in total four periods) after the application of the treatment by spray. Significant differences (P<0.05) were found among treatments for incidence. It was observed that spraying entire cacao trees after two times (approximately 30 days) showed a reduction of monilia infection. After all periods, T1, T2, and T3 showed an incidence of monilia infection by 20.5, 17.7, and 14.9% respectively, compared to cultural control of 41.1%. This reduction of moniliasis infection translates into an increase in fruit weight average for T3 (8.4 kg), T2 (7.3 kg), and T1 (6.9 kg). In contrast, in the control (T3), the fruit weight average decreased by 5.3 kg. Biological control showed efficient management of pathogens as M. roreri. It is recommended to use such antifungal (Aloe vera) spray over at least 120 days which would decrease infection incidence even more.

Manejo agroecológico de la Moniliasis en el cultivo de cacao (Theobroma cacao) mediante la utilización de biofungicidas y podas fitosanitarias en el cantón La Troncal

Moniliophthora roreri es el causante de grandes pérdidas económicas en el sector cacaotero ecuatoriano. La poda de las ramas y el uso de biofungicidas viene puesto a consideración de los agricultores como método de control, sin embargo, se desconoce la efectividad de los mismos cuando se combinan. Así la presente investigación determinó la mejor forma de control de la moniliasis mediante 4 tratamientos en la provincia del Cañar; T1: Bacillus sp +poda; T2: Trichoderma sp+ poda; T3: Mancozeb; T4: Testigo con solo poda. Pese a las diferencias que se mostraron para las variables incidencia, número de flores y pepinos sanos entre los tratamientos, se corrobora que la aplicación de cualquier tipo de fungicida disminuye el daño ocasionado con el hongo y que la poda por sí sola es la menos eficiente. Tal cual lo mostró la variable rendimiento, misma que no presentó diferencias estadísticas entre el tratamiento 1,2 y Sin embargo el análisis económico arrojó como el de mayor rentabilidad al T1 Bacillus sp +poda con una relación beneficio costo de 1,29 dólares con una aplicación de 1,5 l ha-1.

Expression of a Cutinase of Moniliophthora roreri with Polyester and PET-Plastic Residues Degradation Activity

Plastic pollution is exponentially increasing; even the G20 has recognized an urgent need to implement actions to reduce it. In recent years, searching for enzymes that can degrade plastics, especially those based on polyesters such as PET, has been increasing as they can be a green alternative to the actual plastic degradation process.

Caracterización de un jardín clonal de cacao (Theobroma cacao L.) en la amazonía peruana

La variabilidad genética de clones de cacao (<em>Theobroma cacao</em> L.), que existe en el jardín clonal de la Estación Experimental Pichanaqui, de procedencia nacional e internacional, plantea la necesidad de realizar una caracterización morfológica a nivel de frutos, con descriptores morfológicos y escalas para cada tipo de tejido colectado, que usaron como auxiliares las siglas, los colores y formas que permitieron diferenciar las características de cada individuo. Las variables evaluadas fueron número de frutos por planta, peso de mazorcas maduras, numero de granos por mazorca, peso de almendras seca por mazorca, peso de 10 semillas secas, presencia de plagas como la Moniliasis (<em>Moniliophthora roreri</em>), Escoba de bruja (<em>Moniliophthora perniciosa</em>), Mancha parda (<em>Phytophthora palmivora</em>), Perforador (<em>Carmenta foraseminis</em>), Chinche amarillo (<em>Monalonium dissimulatum</em>) y calidad organoléptica en pulpa fresca. Además, se evaluaron variables económicas como el ingreso neto del clon por hectárea. Los resultados indicaron que los mejores clones por su productividad, tolerancia media a plagas y enfermedades, rentabilidad y sabor fueron: ICS 1, ICS 60, SCA 6, ICS 39, y TSH 565. En conclusión, se debería fomentar la siembra de estos clones en los productores de la zona a fin de mejorar su competitividad en el mercado local y nacional.

Moniliophthora roreri (frosty pod rot).

The invasive basidiomycete pathogen M. roreri originated in Western Colombia/Ecuador. In recent years it has expanded its range in South America (Peru, Venezuela and Bolivia) and throughout Mesoamerica as far as Mexico. Africa, Asia and insular Caribbean are still free of this pathogen. M. roreri causes the devastating frosty pod rot of cocoa (Theobroma cacao), a disease that commonly reduces yields by over 80% within a few years of pathogen establishment. The severe losses, and occassionally complete crop failure, frequently render cocoa production economically unfeasible. The results are loss of livelihoods and abandonment and conversion of the affected agroforests to less environmentally sustainable uses, with secondary effects ranging from habitat loss for wildlife, fragmentation of forested landscapes and soil erosion. It is therefore imperative that the introduction of the pathogen to additional cocoa-producing regions is prevented. These include the insular Caribbean, the Guyanas and Brazil in the Americas, as well as the bulk-cocoa producing continents, Africa and Asia (Krauss, 2010).

Adaptive evolution of Moniliophthora PR-1 proteins towards its pathogenic lifestyle

Background Plant pathogenesis related-1 (PR-1) proteins belong to the CAP superfamily and have been characterized as markers of induced defense against pathogens. Moniliophthora perniciosa and Moniliophthora roreri are hemibiotrophic fungi that respectively cause the witches’ broom disease and frosty pod rot in Theobroma cacao. Interestingly, a large number of plant PR-1-like genes are present in the genomes of both species and many are up-regulated during the biotrophic interaction. In this study, we investigated the evolution of PR-1 proteins from 22 genomes of Moniliophthora isolates and 16 other Agaricales species, performing genomic investigation, phylogenetic reconstruction, positive selection search and gene expression analysis. Results Phylogenetic analysis revealed conserved PR-1 genes (PR-1a, b, d, j), shared by many Agaricales saprotrophic species, that have diversified in new PR-1 genes putatively related to pathogenicity in Moniliophthora (PR-1f, g, h, i), as well as in recent specialization cases within M. perniciosa biotypes (PR-1c, k, l) and M. roreri (PR-1n). PR-1 families in Moniliophthora with higher evolutionary rates exhibit induced expression in the biotrophic interaction and positive selection clues, supporting the hypothesis that these proteins accumulated adaptive changes in response to host–pathogen arms race. Furthermore, although previous work showed that MpPR-1 can detoxify plant antifungal compounds in yeast, we found that in the presence of eugenol M. perniciosa differentially expresses only MpPR-1e, k, d, of which two are not linked to pathogenicity, suggesting that detoxification might not be the main function of most MpPR-1. Conclusions Based on analyses of genomic and expression data, we provided evidence that the evolution of PR-1 in Moniliophthora was adaptive and potentially related to the emergence of the parasitic lifestyle in this genus. Additionally, we also discuss how fungal PR-1 proteins could have adapted from basal conserved functions to possible roles in fungal pathogenesis.

SNP markers associated with resistance to frosty pod and black pod rot diseases in an F1 population of Theobroma cacao L.

Economically, cacao (Theobroma cacao L.) is a major tropical commodity for the Americas; however, severe losses due to Moniliophthora roreri (Cif. and Par.), which causes frosty pod rot (FPR), and Phytophthora spp., which causes black pod rot (BPR), have reduced cacao production in the Americas. The objectives of this study are to (i) re-confirm the QTL using different marker set; (ii) discover new QTL associated with FPR and BPR resistance using SNP markers; and (iii) find genes in the candidate QTL regions. At CATIE in Turrialba, Costa Rica, an F1 mapping population of cacao was obtained by crossing “POUND 7,” a clone moderately susceptible to FPR and resistant to BPR, with “UF 273,” resistant to FPR and highly susceptible to BPR. A total of 179 F1 progeny were fingerprinted with 5149 SNP markers and a dense linkage map composed of 10 linkage groups was developed using 2910 polymorphic SNP markers. Also segregating F1 trees were screened for resistance to FPR and BPR diseases. Seven QTL previously reported on chromosomes 2, 7, and 8 for FPR resistance and on chromosomes 4, 8, and 10 for BPR resistance were confirmed. Additionally, eight QTL were identified for FPR resistance (chromosomes 4, 9, and 10) and BPR resistance (chromosome 2). The expression of genes commonly associated with plant defense and disease resistance that are located within the identified QTL was confirmed.

Adaptive evolution ofMoniliophthoraPR-1 proteins towards its pathogenic lifestyle

Moniliophthora perniciosaandMoniliophthora roreriare hemibiotrophic fungi that harbor a large number of Pathogenesis-Related 1 genes, many of which are induced in the biotrophic interaction withTheobroma cacao.Here, we provide evidence that the evolution of PR-1 inMoniliophthorawas adaptive and potentially related to the emergence of the parasitic lifestyle in this genus. Phylogenetic analysis revealed conserved PR-1 genes, shared by many Agaricales saprotrophic species, that have diversified in new PR-1 genes putatively related to pathogenicity inMoniliophthora, as well as in recent specialization cases within both species. PR-1 families inMoniliophthorawith higher evolutionary rates exhibit induced expression in the biotrophic interaction and positive selection clues, supporting the hypothesis that these proteins accumulated adaptive changes in response to host-pathogen arm race. Furthermore, we show that the highly diversifiedMpPR-1genes are not induced by two phytoalexins, suggesting detoxification might not be their main function as proposed before.