Exploring the Genetic Potential for Multi-Resistance to Rust and Other Coffee Phytopathogens in Breeding Programs.

Area of Science:

• Plant genetics
• Agricultural science
• Molecular breeding

Background:

• Marker-assisted selection (MAS) is crucial for developing disease-resistant coffee (Coffea arabica) cultivars.
• Accelerating the identification and concentration of target alleles is essential for pyramiding resistance genes.

Purpose of the Study:

• To develop a coffee population with pyramided resistance genes against major diseases and pests.
• To evaluate the introgression and pyramiding of resistance alleles for coffee leaf rust (CLR) and coffee berry disease (CBD).

Main Methods:

• Artificial crossings between Timor Hybrid and Tupi Amarelo.
• Confirmation of resistance genes using nine molecular markers.
• Phenotypic evaluation for resistance to CLR, cercospora, and leaf miner.
• Mixed models to estimate population superiority for 16 morphoagronomic traits.

Main Results:

• 98.6% of the population showed introgression of CLR and CBD resistance alleles.
• 29% of genotypes exhibited pyramiding of five resistance genes.
• Pyramided genotypes demonstrated 100% resistance to leaf miner and 90% to cercospora.
• 11 significant morphoagronomic traits were identified using repeatability models.

Conclusions:

• Significant genetic variability exists for developing multi-resistant coffee cultivars with high agronomic potential.
• The study successfully demonstrated the pyramiding of resistance genes for enhanced disease and pest resistance in Coffea arabica.