Related Experiment Videos
Vr2: a new apple scab resistance gene
A Patocchi1, B Bigler, B Koller
1Plant Pathology Group, Institute of Plant Sciences, Swiss Federal Institute of Technology, Zürich, Switzerland. andrea.patocchi@ipq.agrl.ethz.ch
Summary
Reports of apple scab (Venturia inaequalis) resistance breakdown highlight the need for new strategies. Researchers identified a new apple scab resistance gene, Vr2, in the GMAL 2473 selection, crucial for developing resistant apple varieties.
Area of Science:
- Plant Pathology
- Genetics
- Horticultural Science
Background:
- The Vf gene, a common source of apple scab resistance, is failing in European orchards.
- Diversifying apple scab resistance genes is critical for sustainable apple breeding.
- Pyramiding multiple resistance genes using molecular markers is a key strategy.
Purpose of the Study:
- To identify molecular markers associated with apple scab resistance in the GMAL 2473 selection.
- To determine if GMAL 2473 carries the known Vr resistance gene.
- To discover and characterize new apple scab resistance genes.
Main Methods:
- Bulked Segregant Analysis (BSA) to identify AFLP and RAPD markers.
- Linkage group identification for apple scab resistance.
- Screening of SSR markers previously mapped to the relevant region.
- Testing GMAL 2473 with known resistance gene markers and vice versa.
Main Results:
- Three AFLP and one RAPD marker were identified as associated with resistance in GMAL 2473.
- A specific SSR marker, CH02c02a, on linkage group 2 co-segregated with the resistance.
- GMAL 2473 was confirmed not to carry the Vr resistance gene.
- Evidence points to the presence of a novel resistance gene in GMAL 2473.
Conclusions:
- A new apple scab resistance gene, designated Vr2, has been identified in the GMAL 2473 apple selection.
- The identified molecular markers, particularly CH02c02a, can be used for marker-assisted selection of Vr2.
- This discovery provides a valuable new tool for breeding durable apple scab resistance.