Potential of the Colombian Coffee Collection as a Source of Genetic Resistance to Colletotrichum kahawae JM Waller PD Bridge

Coffee berry disease (CBD) is not present in the Americas and presents a potential risk for growing coffee. Therefore, Colombia, which has been in scientific cooperation with the Centro de Investigação de Ferrugens do Cafeeiro (CIFC) of Portugal for more than 30 years, has been evaluating the genetic resistance of nine populations of C. arabica to 13 isolates of Colletotrichum kahawae JM Waller and PD Bridge, which are diverse in terms of aggressiveness and geographical origin. The phenotypes observed in the interaction between C. arabica and C. kahawae were used to develop a statistically reliable scale (p-value ≥ 0.001) to categorize resistance in C. arabica into five classes, and this scale was used to classify the nine populations of C. arabica evaluated. The results allowed us to corroborate the potential of Timor Hybrid CIFC 1343 (TH CIFC 1343) as a source of genetic resistance to CBD and to identify new genetic sources not yet explored for the development of varieties in Colombia that may eventually mitigate the effects of CBD in the face of increasing rainfall events and minimum temperatures due to climate change, which can favor disease development. Additionally, the results suggest that the existence of races in the C. arabica–C. kahawae complex is probable, and a selection of genotypes was identified as a possible differential series of races in C. kahawae.