Inducción de resistencia sistémica contra fusarium oxysporum en tomate por trichoderma koningiopsis th003

Trichoderma koningiopsis Th003 ha demostrado ser un eficiente agente de control biológico de diferentes fitopatógenos incluyendo Fusarium oxysporum, además de ser un agente versátil en los modos de acción implicados en la respuesta de biocontrol. Con el propósito de estudiar la capacidad de este biocontrolador para inducir respuestas sistémicas de defensa en el control de la infección de Fusarium oxysporum, se utilizaron plantas de tomate (Solanum lycopersicum Mill.) establecidas en cubos de enraizamiento con el sistema radical separado en dos porciones. Cuando Th003 se inoculó en una porción de la raíz 96 h antes de inocular F. oxysporum en la otra porción se presentó un retraso de la colonización del fitopatógeno en el sistema vascular de la planta, en comparación con las plantas inoculadas solamente con el fitopatógeno. Este resultado sugiere que T. koningiopsis Th003 estimuló respuestas sistémicas de defensa en la planta, dado que el antagonista y el fitopatógeno permanecieron separados espacialmente. Cuando el microorganismo biocontrolador fue evaluado en un cultivo comercial de tomate bajo invernadero, éste redujo significativamente (P and lt;0.05) la incidencia de la enfermedad causada por F. oxysporum en 35%, en comparación con el testigo absoluto. El hongo T. koningiopsis Th003 demostró su habilidad para controlar F. oxysporum f. sp. radicis-lycopersici mediante inducción de respuestas de defensa sistémica en las plantas de tomate

Rubber tapping system effect on the productivity of Hevea brasiliensis in the Colombian Middle Magdalena

Páginas 184-192.Los sistemas de sangría con estimulación se usan para minimizar costos y aumentar la producción de látex. Por ello, se evaluaron sistemas de sangría con diferentes frecuencias con y sin estimulación con EthrelÒ y niveles de fertilización en un cultivo del FX3864 de Hevea brasiliensis de 9 años de edad en Barrancabermeja, Santander. El estudio se realizó con un diseño de parcelas divididas distribuido en bloques al azar, considerando como parcela principal los sistemas de sangría con diferentes frecuencias con y sin estimulación y como subparcela los tratamientos de fertilización con dosis combinadas de N, P y K. La producción de caucho seco, consumo de corteza, incidencia de seca fisiológica, contenido de caucho seco y la rentabilidad económica se consideraron como variables de respuesta. La producción más alta se obtuvó con los sistemas d/3 E y d/4 E (1.446 y 1.281 kg ha-1 año-1, respectivamente), con diferencias significativas con los sistemas d/3 S.E y d/5 E. Entre los tratamientos de fertilización no se encontró diferencias significativas, aunque la mayor producción se obtuvieron con los niveles 40-40-40 kg ha-1 y 80-80-80 kg ha-1 de N, P y K. En cuanto a los mayores niveles foliares de N, P, K y Ca se encontraron en el sistema d/4 E. Con estos resultados se recomienda el sistema de sangría d/4 E por tener la mejor rentabilidad económica bajo diferentes rendimientos del sangrador, menor consumo de corteza (3,86 cm), mayor vida útil de la plantación (3,85 años) y menor incidencia de enfermedades de panel.ABSTRACT: Tapping systems with stimulation are used to minimize costs and improve latex yield. For this, tapping systems with different frequencies and with or without Ethrel® stimulation and fertilizer levels were evaluated in a 9-yearold crop of FX3864 of Hevea brasiliensis in Barrancabermeja, Santander. In this study, a split plot design with randomized complete blocks was used, where the tapping systems with different frequencies with or without stimulation were considered as the principal plot and the fertilization treatments with combined dosages of N, P and K were considered as the subplots. The dry rubber yield, bark consumption, tapping panel dryness incidence, dry rubber content and profitability were considered as response variables. The systems d/3 E and d/4 E obtained the highest yield (1,446 and 1,281 kg ha-1 yr-1, respectively), with significant differences with the systems d/3 S.E and d/5 E. For the fertilization treatments, there were no significant differences. Notwithstanding, the highest yields were obtained in the 40-40-40 kg ha-1 and 80-80-80 kg ha-1 of N, P and K balanced treatments. The higher foliar levels of N, P, K and Ca were founded in the d/4 E system. According to these results, the d/4 E tapping system is recommended to be the most profitable under different tapping yields, with less bark consumption (3.86 cm), longer life plantation (3.85 years) and less disease panel incidence.Bibliografía: página 192.Artículo revisado por pares

Cacao agroforestry systems beyond the stigmas: Biotic and abiotic stress incidence impact

Low technological knowledge in production chains, global climate change, and misinformation are concrete threats to food security. In addition, these combined threats also trigger ecological instability in megadiverse areas of the world, especially in some cacao-producing countries in South America, where this crop plays an important socio-economic role, even being used to replace illicit crops. Accordingly, the use of agroforestry systems approaches has emerged as a good alternative to maintain productivity, add high-value commodities to producers, and provide important ecosystem services for sustainable agriculture. However, limitations associated with the competition for resources between the species composing the system, and the higher incidence of some diseases, have led many producers to abandon this strategy, opting for monoculture. In this review, we seek to gather the main information available in the literature, aiming to answer the question: what is the real scientific evidence that supports the benefits and harms of adopting agroforestry systems in cacao production? We seek to make critical scrutiny of the possible negative effects of certain associations of the agroforestry system with biotic and abiotic stress in cacao. Here, we review the possible competition for light and nutrients and discuss the main characteristics to be sought in cacao genotypes to optimize these inter-specific relationships. In addition, we review the research advances that show the behavior of the main cacao diseases (Witch’s broom disease, frosty pod rot, black pod rot) in models of agroforestry systems contrasted with monoculture, as well as the optimization of agronomic practices to reduce some of these stresses. This compendium, therefore, sheds light on a major gap in establishing truly sustainable agriculture, which has been treated much more from the perspective of negative stigma than from the real technological advantages that can be combined to the benefit of a balanced ecosystem with generating income for farmers

Estrutura da população e epidemiologia de Moniliophthora roreri no Magdalena Medio Colombiano

A Moniliase do cacaueiro, causada pelo fungo Moniliophthora roreri, é uma das doenças mais devastadoras do cacaueiro na região oeste da América do Sul e Central, por exemplo, a região do Vale do Magdalena na Colômbia, considerada o possível centro de origem para á espécie. Para analisar a diversidade genética foram utilizados isolados dos estados de Santander, Antioquia, Tolima e Huila da Colômbia utilizando vinte-três marcadores microssatélites (SSR). No total, 117 genotipos multilocus diferentes se encontraram entre os 120 isolados, cada um representado como um haplotipo único. O índice de associação observado e estandardizado (IA e řd) indicaram que as populações de M. roreri são clonais. Além disso, dada a alta diversidade de haplotipos com desequilíbrio de ligação se sugere que M. roreri poderia ser uma espécie assexual possivelmente com recombinação rara ou parcial devida à parasexualidade. Enquanto a estrutura populacional, três grupos geográficos foram reconhecidos entre os isolados utilizando métodos de agrupamento bayesianos. Resultados similares se obtiveram depois do analises discriminante de componentes principais (DAPC), analise de coordenadas principais (PCA) e a arvore de semelhança com os loci dos microssatélites baseados na distância de Nei. A identificação destes agrupamentos explicasse pela diferenciação geográfica e clones de cacaueiro e variáveis ambientais não contribuem significativamente à diferenciação genéticas entre os grupos. Em relação a epidemiologia da doença foi monitorada a incidência da moniliase no tempo e no espaço em clones com diferente grau de resistência em quatro localidades do Estado de Santander entre Julho de 2013 até Maio de 2015. O modelo linear generalizado se utilizou para analisar o progresso temporal e espacial da Moniliase. A distribuição de Poisson com função de ligação logarítmica se selecionou pela superdispersão dos dados. Uma interação significativa se encontrou entre os clones e localidades sobre os parâmetros epidemiológicos. O clone suscetível SCC 61 apresentou o maior intensidade de doença na maioria das localidades, a exceção de San Vicente onde tive o mais baixo nível. A localidade de San Vicente apresentou a mais baixa intensidade de doença em todos os clones de cacaueiro, quando comparado com as outras localidades. Depois de aplicar o teste de Moran I aos dados de frutos doentes cortados no centro de pesquisa La Suiza, foi evidente a autocorrelação espacial. O estudo da dinâmica demostrou que as epidemias da moniliase variam de acorde com a localidade e o material vegetal e sua localização no campo. As informações obtidas neste trabalho podem ser empregadas para melhorar o manejo da moniliase ao nível regional e as práticas deverão ser ajustadas considerando a variação do microambiente.Frosty pod rot disease (FPR) on cocoa, caused by Moniliophthora roreri, is one of the most devastating cocoa diseases in the Western Hemisphere, including the Magdalena Valley areas in Colombia, which is considered the possible center of origin for the species. We analyzed the genetic diversity of isolates from the states Santander, Antioquia, Tolima and Huila of Colombia using twenty-three simple sequence repeats (SSR) markers. In total, 117 different multilocus genotypes were found among 120 isolates, each one represented as a unique haplotype. The observed and standardized index of association (IA and řd) indicates that the populations of M. roreri are clonal populations. Furthermore, given the high haplotype diversity with linkage disequilibrium are suggest that M. roreri could be an asexual species possibly undergoing rare recombination or partial recombination due to parasexuality. Three geographical groups were recognized among the isolates using Bayesian clustering methods. Similar results were obtained after discriminant analysis of principal components (DAPC), principal coordinate analysis (PCA) and a neighbor-joining tree from microsatellite loci based on Nei distance. The identified clusters where explained by geographical differentiation and cacao clones and environmental variables did not contribute significantly to the genetic differentiation between groups. Regarding to the disease epidemiology, incidence of Frosty Pod Rot (FPR) disease, caused by Moniliophthora roreri, in time and space on clones with different level of resistance were investigated in four localities of Santander State between July 2013 and May 2015. Generalized linear model was used to analyze the temporal and spatial progress of FPR. Poisson distribution with logarithm link function was chosen because of data overdispersion. A significant interaction was found between clones and localities on epidemics parameters. The susceptible clone SCC61 had the higher levels of disease in the most localities, excepted in San Vicente where it obtained the lower level. The locality in San Vicente had the lower levels of disease in all cacao clones, when compared with the other localities. After applied Moran’s I test to data of cut disease pod in La Suiza Research Center, were evident in spatial autocorrelation. The dynamic study provide that FPR epidemics vary according to location and plant material and its location on the plot. The information obtained in this word could be used to improve the management of FPR at the regional level and the practices will be adjusted to local level considering microenvironmental variation.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Inducción de resistencia sistémica contra Fusarium oxysporum en tomate por Trichoderma koningiopsis Th003

Trichoderma koningiopsis Th003 ha demostrado ser un eficiente agente de control biológico de diferentes fitopatógenos incluyendo Fusarium oxysporum, además de ser un agente versátil en los modos de acción implicados en la respuesta de biocontrol. Con el propósito de estudiar la capacidad de este biocontrolador para inducir respuestas sistémicas de defensa en el control de la infección de Fusarium oxysporum, se utilizaron plantas de tomate (Solanum lycopersicum Mill.) establecidas en cubos de enraizamiento con el sistema radical separado en dos porciones. Cuando Th003 se inoculó en una porción de la raíz 96 h antes de inocular F. oxysporum en la otra porción se presentó un retraso de la colonización del fitopatógeno en el sistema vascular de la planta, en comparación con las plantas inoculadas solamente con el fitopatógeno. Este resultado sugiere que T. koningiopsis Th003 estimuló respuestas sistémicas de defensa en la planta, dado que el antagonista y el fitopatógeno permanecieron separados espacialmente. Cuando el microorganismo biocontrolador fue evaluado en un cultivo comercial de tomate bajo invernadero, éste redujo significativamente (P<0.05) la incidencia de la enfermedad causada por F. oxysporum en 35%, en comparación con el testigo absoluto. El hongo T. koningiopsis Th003 demostró su habilidad para controlar F. oxysporum f. sp. radicis-lycopersici mediante inducción de respuestas de defensa sistémica en las plantas de tomate

Cadmium up Taking and Allocation in Wood Species Associated to Cacao Agroforestry Systems and Its Potential Role for Phytoextraction

Trees in cacao Agroforestry systems (AFS) may present a high potential for cadmium (Cd) phytoextraction, helping to reduce Cd in cacao (Theobroma cacao L.) plants grown in contaminated soils. To assess this potential, four forest fine-woody species commonly found in cacao high-productive sites in Colombia (Tabebuia rosea, Terminalia superba, Albizia guachapele, and Cariniana pyriformis) were exposed to contrasting CdCl2 contamination levels (0, 6, and 12 ppm) on a hydroponic medium. Growth dynamics, tolerance index (TI), and Cd concentration and allocation in leaves, stems, and roots were evaluated for up to 90 days after initial exposure. T. superba, A. guachapele, and C. pyriformis were classified as moderately tolerant (TI > 0.6), and T. rosea was considered a sensitive species (TI C. pyriformis also showed the lowest relative growth rate. Among the evaluated forest species, A. guachapele exhibited the highest Cd accumulation capacity per plant (2.02 mg plant−1) but also exhibited a higher Cd allocation to leaves (4%) and a strong decrease in leaf and stem dry mass after 90 days of exposure (~75% and 50% respectively, compared to control treatments). Taking together all the favorable features exhibited by T. superba as compared to other CAFS tree species and recognized phytoextractor tree species in the literature, such as Cd hyperaccumulation, high tolerance index, low Cd concentration in leaves, and high Cd allocation to the stem (harvestable as wood), this species is considered to have a high potential for cadmium phytoextraction in cocoa agroforestry systems

Unveiling Cacao Rootstock-Genotypes with Potential Use in the Mitigation of Cadmium Bioaccumulation

The accumulation of high cadmium (Cd) levels in cacao beans (Theobroma cacao) generate several commercial and health issues. We hypothesized that cacao phenotypic and genotypic diversity could provide new insights to decrease Cd accumulation in cacao beans. Nine cacao rootstock genotypes were evaluated for up to 90 days under 0, 6, and 12 (mg·kg−1) of CdCl2 exposure and Cd content and plant growth dynamics were measured in leaves, stems, and roots. Data revealed that all cacao genotypes studied here were highly tolerant to Cd, since they presented tolerance index ≥ 60%. In shoots, EET61 and PA46 presented the higher (~270 mg·kg DW−1) and lower (~20 mg·kg DW−1) Cd concentration, respectively. Accordingly, only the EET61 showed an increase in the shoot cadmium translocation factor over the 90 days of exposure. However, when analyzing cadmium allocation to different organs based on total plant dry mass production, none of the genotypes maintained high Cd compartmentalization into roots, since P46, which was the genotype with the highest allocation of Cd to the roots, presented only 20% of total cadmium per plant in this plant organ and 80% allocated into the shoots, under Cd 12 (mg·kg−1) and after 90 days of exposure. Thus, genotypic/phenotypic variability in cacao rootstocks may provide valuable strategies for maximizing the reduction in Cd content in shoots. In this sense, IMC67 and PA46 were the ones that stood out in the present study