Genetic biodiversity of yellow rust resistance in wheat

National and international programs have characterised sources of partial, field resistance and race-specific R-gene resistance to yellow rust in wheat.

Studies involving European wheat cultivars have focussed on the field resistance to yellow rust present in cv. Claire and cultivars within the Claire pedigree, including sources of resistance derived from old European wheat cultivars. Mutants in the UK cv. Guardian, selected for enhanced resistance to yellow rust, reveal existing, partial yellow rust resistance QTLs in Guardian which appear additive with the mutant loci.

Scoring wheat trials for yellow rust infection in South Africa

International links with CIMMYT (the International Maize and Wheat Improvement Centre) have lead to a number of collaborative programs. A comparative marker analysis in Turkish wheat cultivars (CIMMYT, Ankara, Turkey), compared to a sub-set of European cultivars, has identified distinct sources of yellow rust resistance. Collaborative programs with South Africa identified a new QTL for partial, yellow rust resistance on chromosome 2B in the South African wheat cv. Kariega (Ramburan et al., 2004).

PCR-based markers developed for the yellow rust R-genes, Yr5 (Smith et al., 2007) and Yr10 (Smith et al., 2002) have provided tools for marker assisted selection breeding and are currently being used to stack these R-genes, along with partial QTLs for yellow rust resistance into French wheat cultivars as part of a European Union Integrated Project.

Expertise

The group has extensive expertise in genetic mapping, QTL analysis and DNA marker development.