Constitutive Defense Strategy of Coffee Under Field Conditions: A Comparative Assessment of Resistant and Susceptible Cultivars to Rust.

Coffea arabica is the most economically important coffee species worldwide. However, its production is severely limited by diseases such as rust. The mechanisms underlying constitutive defense responses in coffee are still poorly understood, compared with induced defense mechanisms. We aimed to characterize constitutive defense responses of thirteen cultivars of C. arabica. Cultivars were classified under field conditions according to the level of resistance to rust: resistant (R), moderately resistant (MR), and susceptible (S). Based on this classification, the stability of eight reference genes (RGs) was evaluated. The most stable RGs were EF1α, APT1, and 24S. We also evaluated the expression of CaWRKY1, CaPAL1, CaCAD1, and CaPOX1, and activities of PAL, CAD, and POX, which are involved in lignin biosynthesis, and leaf content of total phenolic compounds and lignin. Gene expression and enzymatic activity were not correlated with defense metabolites in the R cultivar group but showed a negative correlation with phenolic compounds in MR cultivars. Cultivar S showed positive correlations of gene expression and enzyme activity with phenolic compounds. These results may assist coffee breeding programs regarding selection of genotypes and in optimization of rust resistance.

Indicadores de qualidade do solo cultivado com café, pastagem e integração pastagem e eucalipto / Quality indicators of soil cultivated with coffee, pasture, and pasture and eucalyptus integration / Indicadores de calidad del suelo cultivado con café, pastaje e integración pastaje y eucalipto

A demanda crescente da utilização dos solos exige soluções que permitam incentivar o desenvolvimento socioeconômico sem comprometer a sustentabilidade dos recursos naturais. Desse modo, o objetivo deste estudo foi avaliar os efeitos de diferentes culturas como café, pastagem e manejo integrado de pastagem e eucalipto na qualidade química e microbiológica do solo. Foram analisados da parte química o pH do solo, nitrogênio, carbono orgânico total e fósforo do solo e da parte microbiológica foram analisados a densidade de esporos de fungos micorrizicos arbusculares (FMAs), carbono da biomassa microbiana (CBM), respiração basal do solo e coeficiente metabólico do solo qCO2. O pH do solo variou de 5,38 no manejo de pasto e eucalipto para 4,70 nas áreas cultivadas com pasto. A densidades de esporos de FMAs e o CBM na área de integração de pasto e eucalipto foram aumentados em relação à área cultivada com café, e o qCO2 foi aumentado com o cultivo do café, indicando que o cultivo de café eleva a condição de estresse do solo nas condições avaliadas. Concluindo, portanto, que as diferentes formas de uso e manejo das três áreas estudadas apontaram variações do comportamento de suas propriedades químicas e microbiológicas, entretanto, o manejo que se destacou foi a de eucalipto com a integração de pastagens, sendo mais sustentável.(AU)

The increasing demand for land use requires solutions that encourage its socio-economic development without compromising the sustainability of natural resources. The purpose of this study was to evaluate the effects of different crops such as coffee, pasture and the integrated management of pasture and eucalyptus in the chemical and microbiological quality of the soil. Chemical tests were performed to obtain the pH, nitrogen, total organic carbon, and phosphorus contents on the land, while microbiological parameters analyzed the density of arbuscular mycorrhizal fungi (AMF) spores, microbial biomass carbon (MBC), soil basal respiration (SBR) and soil metabolic coefficient qCO2. The soil pH varied from 5.38 in the management of pasture and eucalyptus to 4.70 in the areas cultivated with only pasture. The density of AMF spores and the MBC were higher in the pasture and eucalyptus integration when compared with coffee cultivation; the qCO2 in soil with coffee was higher than that found for the integration of pasture and eucalyptus. Those results indicate that coffee cultivated in those conditions increase stress in the soil due to higher SBR. It can be concluded that the different forms of use and management of the three studied areas show variations in the behavior of the chemical and microbiological properties in the soil, and eucalyptus with pasture integration presents a better sustainable soil management.(AU)

La demanda creciente de utilización del suelo exige soluciones que permitan incentivar el desarrollo socioeconómico sin comprometer la sustentabilidad de los recursos naturales. Así, el objetivo de ese estudio ha sido evaluar los efectos de diferentes culturas como café, pastaje y manejo integrado de pastaje y eucalipto en la calidad química y microbiológica del suelo. Se analizaron de la parte química, el pH del suelo, nitrógeno, carbono orgánico total y fosforo del suelo, y de la parte microbiológica se analizaron la densidad de esporos de fungos micorrizicos arbusculares (FMAs), carbono de la biomasa microbiana (CBM), respiración basal del suelo y coeficiente metabólico del suelo qCO2. El pH del suelo osciló de 5,38 en el manejo de pasto y eucalipto para 4,70 las áreas cultivadas con pasto. La densidad de esporos de FMAs y el CBM en el área de integración de pasto y eucalipto han aumentado en relación al área cultivada con café, y el qCO2 fue aumentado con el cultivo de café, indicando que el cultivo de café eleva la condición de estrés del suelo en las condiciones evaluadas. Concluyendo, por lo tanto, que las diferentes formas de uso y manejo de las tres áreas estudiadas, apuntaron variaciones de comportamiento de sus propiedades químicas y microbiológicas, entretanto el manejo que se destacó fue la del eucalipto con la integración de pastajes, siendo más sostenible.(AU)

An integrated framework for assessing vulnerability to climate change and developing adaptation strategies for coffee growing families in Mesoamerica.

The Mesoamerican region is considered to be one of the areas in the world most vulnerable to climate change. We developed a framework for quantifying the vulnerability of the livelihoods of coffee growers in Mesoamerica at regional and local levels and identify adaptation strategies. Following the Intergovernmental Panel on Climate Change (IPCC) concepts, vulnerability was defined as the combination of exposure, sensitivity and adaptive capacity. To quantify exposure, changes in the climatic suitability for coffee and other crops were predicted through niche modelling based on historical climate data and locations of coffee growing areas from Mexico, Guatemala, El Salvador and Nicaragua. Future climate projections were generated from 19 Global Circulation Models. Focus groups were used to identify nine indicators of sensitivity and eleven indicators of adaptive capacity, which were evaluated through semi-structured interviews with 558 coffee producers. Exposure, sensitivity and adaptive capacity were then condensed into an index of vulnerability, and adaptation strategies were identified in participatory workshops. Models predict that all target countries will experience a decrease in climatic suitability for growing Arabica coffee, with highest suitability loss for El Salvador and lowest loss for Mexico. High vulnerability resulted from loss in climatic suitability for coffee production and high sensitivity through variability of yields and out-migration of the work force. This was combined with low adaptation capacity as evidenced by poor post harvest infrastructure and in some cases poor access to credit and low levels of social organization. Nevertheless, the specific contributors to vulnerability varied strongly among countries, municipalities and families making general trends difficult to identify. Flexible strategies for adaption are therefore needed. Families need the support of government and institutions specialized in impacts of climate change and strengthening of farmer organizations to enable the adjustment of adaptation strategies to local needs and conditions.

Caveats to quantifying ecosystem services: fruit abortion blurs benefits from crop pollination.

The recent trend to place monetary values on ecosystem services has led to studies on the economic importance of pollinators for agricultural crops. Several recent studies indicate regional, long-term pollinator declines, and economic consequences have been derived from declining pollination efficiencies. However, use of pollinator services as economic incentives for conservation must consider environmental factors such as drought, pests, and diseases, which can also limit yields. Moreover, "flower excess" is a well-known reproductive strategy of plants as insurance against unpredictable, external factors that limit reproduction. With three case studies on the importance of pollination levels for amounts of harvested fruits of three tropical crops (passion fruit in Brazil, coffee in Ecuador, and cacao in Indonesia) we illustrate how reproductive strategies and environmental stress can obscure initial benefits from improved pollination. By interpreting these results with findings from evolutionary sciences, agronomy, and studies on wild-plant populations, we argue that studies on economic benefits from pollinators should include the total of ecosystem processes that (1) lead to successful pollination and (2) mobilize nutrients and improve plant quality to the extent that crop yields indeed benefit from enhanced pollinator services. Conservation incentives that use quantifications of nature's services to human welfare will benefit from approaches at the ecosystem level that take into account the broad spectrum of biological processes that limit or deliver the service.