RESUMO
Coffee has immense value as a worldwide-appreciated commodity. However, its production faces the effects of climate change and the spread of severe diseases such as coffee leaf rust (CLR). The exploration of fungal endophytes associated with Coffea sp. has already found the existence of nearly 600 fungal species, but their role in the plants remains practically unknown. We have researched the diversity of leaf fungal endophytes in two Coffea arabica varieties: one susceptible and one resistant to CLR. Then, we conducted cross-infection essays with four common endophyte species (three Colletotrichum sp. and Xylaria sp. 1) and Hemileia vastatrix (CLR) in leaf discs, to investigate the interaction of the endophytes on CLR colonisation success and severity of infection. Two Colletotrichum sp., when inoculated 72 h before H. vastatrix, prevented the colonisation of the leaf disc by the latter. Moreover, the presence of endophytes prior to the arrival of H. vastatrix ameliorated the severity of CLR. Our work highlights both the importance of characterising the hidden biodiversity of endophytes and investigating their potential roles in the plant-endophyte interaction.
RESUMO
The use and conservation of agrobiodiversity have become critical to face the actual and future challenges imposed by climate change. Collecting phytogenetic resources is a first step for their conservation; however, the genetic material must be analysed to understand their potential to improve agricultural resilience and adaptation to the new climatic conditions. We have selected nine Phaseolus vulgaris, one P. lunatus and two Vigna unguiculata landraces from two different climatic backgrounds of the Andean region of South Ecuador and one P. vulgaris commercial cultivar, and we grew them under two different conditions of temperature and humidity (open field and greenhouse). Then, we recorded data for 32 characters of plant architecture, flower and fruit characteristics and yield, and 17 events in the phenology of the plants. We analysed the impact of treatment on species, climatic background, and each of the landraces, and identified both characters and landraces that are mostly affected by changes in their environmental conditions. Overall, higher temperatures were benign for all materials except for two P. vulgaris landraces from cold background, which performed better or developed faster under cold conditions. Finally, we calculated a climate resilience landrace index, which allowed us to classify the landraces by their plasticity to new environmental conditions, and found heterogeneous landrace susceptibility to warmer conditions. Two P. vulgaris landraces were highlighted as critical targets for conservation.
Assuntos
Phaseolus , Vigna , Agricultura , Frutas , Variação Genética , Phaseolus/genética , Vigna/genéticaRESUMO
Ant-associated microorganisms can play crucial and often overlooked roles, and given the diversity of interactions that ants have developed, the study of the associated microbiomes is of interest. We focused here on specialist plant-ant species of the genus Allomerus that grow a fungus to build galleries on their host-plant stems. Allomerus-inhabited domatia, thus, might be a rich arena for microbes associated with the ants, the plant, and the fungus. We investigated the microbial communities present in domatia colonised by four arboreal ants: Allomerus decemarticulatus, A. octoarticulatus, A. octoarticulatus var. demerarae, and the non-fungus growing plant-ant Azteca sp. cf. depilis, inhabiting Hirtella physophora or Cordia nodosa in French Guiana. We hypothesized that the microbial community will differ among these species. We isolated microorganisms from five colonies of each species, sequenced the 16S rRNA or Internal TranscribedSpacer (ITS) regions, and described both the alpha and beta diversities. We identified 69 microbial taxa, which belong to five bacterial and two fungal phyla. The most diverse phyla were Proteobacteria and Actinobacteria. The microbial community of Azteca cf. depilis and Allomerus spp. differed in composition and richness. Geographical distance affected microbial communities and richness but plant species did not. Actinobacteria were only associated with Allomerus spp.
RESUMO
Changing climatic conditions impose a challenge both to biodiversity and food security. The effects of climate change affect different aspects of the plant or crop, such as morphological and phenological aspects, as well as yield. The effects of greenhouse conditions might be comparable in some cases to a permanent extreme disturbance in climate and weather, thus, contributing to our knowledge on climate change impacts on plant species. We have investigated the differences for 23 traits in two cultivar groups of an Andean traditional crop, Solanum betaceum, under two different environmental conditions that correspond to the traditional practices in the open field and three cultural managements under greenhouse conditions (no fertilization or control, organic, and mineral). We found that traditional practices in the open field are the less productive. Moreover, in warmer and drier conditions the treatment with organic fertilization was the most productive. Greenhouse conditions, however, delay production. We further identified traits that differentiate both cultivar groups and traits that are linked to either the new climate conditions or the fertilization treatments. Fruit characteristics were quite homogeneous between the two cultivar groups. Overall, our results provide insight on the consequences that climate change effects might exert on crops such as tree tomato, reveal that greenhouses can be a robust alternative for tree tomato production, and highlight the need to understand how different managements are linked to different solutions to fulfil the farmers' demands.