Sunflower
Person in charge: Maren Livaja
Identification of resistance genes against downy mildew in sunflower
One of the major limiting factors of sunflower cultivation is the high risk of destructive fungal diseases. Downy mildew caused by the oomycete Plasmopara halstedii (Farl.) Berl & De Toni is one of the most important diseases. To identify resistance genes against downy mildew in sunflower, innovative breeding strategies are applied. High-throughput sequencing and genotyping are used for the characterization and cloning of the PlARG resistance locus on linkage group 1. The detailed haplotype analysis of the gene locus will accelerate the marker-assisted transfer of this resistance into elite breeding material.
Polygalacturonase-inhibiting proteins as possible source for improving sunflower resistance to fungal pathogens
Natural defense mechanisms of plants might be further improved by advantageous pyramiding of genes encoding proteins that suppress important pathogenicity factors. Endo-polygalacturonases (endoPGs) act as cell-wall degrading enzymes and contribute to the virulence of fungal and bacterial pathogens, as well as oomycetes. However, plants have evolved families of polygalacturonase-inhibiting proteins (PGIPs) that specifically recognize and inactivate these polygalacturonases (PGs). Objective of this work is to elucidate the role of pgip-genes for sunflower defense against a diverse range of fungi and oomycetes.
Powdery mildew in sunflower
Powdery mildew of sunflower is caused by the obligate fungal biotroph Golovinomyces cichoracearum var. cichoracearum (DC.) V.P. Heluta. A strong infection of plants by powdery mildew (PM) results in twisted, chlorotic leaves and premature drying of plants which subsequently reduces seed number and oil yield.
In order to reduce costs for chemical control of PM, and to keep the environmental pollution as low as possible, the use of cultivars with genetic sources of PM resistance is the preferred breeding strategy. The germplasm pool PM1 developed from interspecific hybridization between Helianthus debilis Nutt.and cultivated sunflower is the only resistance source known so far. The resistance was suggested to be under control of few major genes but candidates are still missing. First discovered in barley, loss of function mutations in plant-specific MLO (Mildew Resistance Locus O) genes have been shown to confer broad-spectrum powdery mildew resistance in a number of plant species. The current work aims at the identification and molecular analysis of candidate HaMLO PM susceptibility genes.
