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Gafa, or anthracnose, is a disease of the olive grove caused by several species of fungus of the genus Colletotrichum, such as Colletotrichum accutatum, C. nymphaeae or C. godetiae [1,2]. Symptoms typically appear on ripening olives and include: brownish/black spots with depression, dehydration and early fall. In extreme cases, defoliation and branch death can occur [3]. The presence of diseased olives also has a negative influence on olive oil quality, increasing acidity and lowering the oil's oxidative stability [4].

Gafa is considered the main disease in olive groves in Portugal and is one of the diseases that will be monitored in the AlViGen project. In order to be able to monitor the strains of Colletotrichum present in the olive grove and derive useful information from this monitoring, we need to have an association between the genome and the phenotype of these strains. That way, when we apply genomic surveillance to Colletotrichum If we identify a particular genotype, we can also identify its phenotypic characteristics. For example, its virulence or pattern of resistance to fungicides.

In order to have this association between genetics and the phenotype of the Colletotrichum, We are working with Rosário Félix's group, a professor at the University of Évora, on the isolation and characterization of strains of Colletotrichum isolated throughout the country. As such, we are asking for the community's help in sending us olive samples so that we can characterize the Colletotrichum present in your olive grove!

The process is very simple:

1. Put 10 olives in a bag (of a single variety) at the time of the color change (with or without symptoms).

2. Fill in the questionnaire to characterize the sample, using your cell phone (see below).

3. Write the sample code on the bag (code generated when filling in the form)

4. Put the bag in a box or padded envelope and send it to:
Maria do Rosário Félix
Plant Virology Laboratory, room 108, Santos Júnior Building
Mitra Center, University of Évora 7000-083 Évora

Cell phone data collection form

So that we can collect data about the sampling site and the type of farm, we ask those who send us samples to also fill in a questionnaire via cell phone.

iPhones

Collect the data using the google form that you can access in your browser, via: https://forms.gle/688GGnJC6qYHC3Lk9

Android phones

Collect the data using the ODK collect app, which you can download for free from the Google Play Store at: https://play.google.com/store/apps/details?id=org.odk.collect.android&hl=en&gl=US

Once the application is installed, you can access the form with the QR code below using two methods: click on “Configure with QR code” and use the camera to add the QR code below. Alternatively, download the QR code and after clicking on “Configure with QR code”, click on the three dots (top right) and click on “Import QR Code”. From here you will have uploaded the QR code and simply click on “Blank Form” to start adding your sample data.

References

1. Materatski, P., Varanda, C., Carvalho, T., Dias, A. B., Campos, M. D., Rei, F., & Félix, M. D. R. (2018). Diversity of Colletotrichum species associated with olive anthracnose and new perspectives on controlling the disease in Portugal. Agronomy, 8(12), 301.

2. Talhinhas, P., Mota-Capitão, C., Martins, S., Ramos, A. P., Neves-Martins, J., Guerra-Guimarães, L., ... & Oliveira, H. (2011). Epidemiology, histopathology and aetiology of olive anthracnose caused by Colletotrichum acutatum and C. gloeosporioides in Portugal. Plant Pathology, 60(3), 483-495.

3. Talhinhas, P., Sreenivasaprasad, S., Neves-Martins, J., & Oliveira, H. (2005). Molecular and phenotypic analyses reveal association of diverse Colletotrichum acutatum groups and a low level of C. gloeosporioides with olive anthracnose. Applied and Environmental Microbiology, 71(6), 2987-2998.

4. Carvalho, M. T., Simões-Lopes, P., & Monteiro da Silva, M. J. (2008). Influence of different olive infection rates of Colletotrichum acutatum on some important olive oil chemical parameters. In V International Symposium on Olive Growing 791 (pp. 555-558).