Nuhu Mbwebwe Aman^1,, Fatuma Jumapili Ramadhani¹, Neyonkulu S. Kahisha¹, Lilian Fanuel Shechambo², Grace Kitange Monyo¹, Deusdedith Kilambo¹

Preserving the coffee's genetic resources through seeds is insufficient due to its short longevity. The coffee germplasm is conserved in the field gene banks or in cold storage (cryopreservation), ensuring the genetic resources' longevity. The repeated occurrence of new virulent races of the coffee leaf rust caused by Hemillia vastrist Berk et Br, and the breakdown of the resistance have challenged breeders to keep searching for other sources of resistance to CLR. This study aimed to identifying coffee accessions resistant to CLR under natural infestation and documenting their cup profile for genetic resource conservation and sustainable utilization. Thirteen coffee accessions were evaluated for their response to CLR and cup scores were documented. The experiment was laid out in a complete randomized block design with six replications. The CLR was assessed using a scale of 1 to 6 based on disease symptoms. The 250g of seed from each accession was collected to establish its cup profile using the Sensory method. Significant differences in the reaction to CLR and variation of cup score were observed. Coffee accession I5, AC98, and R3 were observed to be tolerant to CLR with excellent cup scores while KP532, N197, N110, and M95 were observed to be susceptible to CLR with cup scores ranging from good to excellent. The screened accessions with tolerance to CLR can be utilized in the breeding program. However, molecular characterization to identify and confirm the gene of resistance is important following more field and laboratory evaluation.

coffee leaf rust, coffee germplasm, resistance, susceptible