Seminar of two invited speakers: Prof. Ralph Panstruga and Prof. Jaime Prohens

Venue:  Room C0313
Contact: Prof. Richard Visser and Prof. Yuling Bai, Plant Breeding, WUR

13:00 – 14:00:  Dr. Ralph Panstruga, Professor at RWTH Aachen University, Aachen, Germany

Phenotypic and molecular characterization of partially mlo-virulent isolates of the barley powdery mildew pathogen (Blumeria graminis f.sp. hordei)

Barley (Hordeum vulgare) loss-of-function mlo mutants exhibit durable broad-spectrum powdery mildew resistance. During the last decades, this type of disease resistance has been widely used in European agriculture and it is still highly effective under field conditions. We deployed an experimental evolution strategy to select isolates of the barley powdery mildew pathogen, Blumeria graminis f.sp. hordei, that have gained partial virulence on barley mlo genotypes. I will present the phenotypic and molecular characterization of one of these isolates (SK1) in comparison with its parental strain (K1). The SK1 isolate shows an essentially unaltered virulence profile on nonhost wheat and Arabidopsis plants and also exhibits largely retained sensitivity to resistance (R) gene-mediated immunity. However, we observed a consistent reduction in host cell entry rates on a panel of susceptible barley wild-type cultivars, suggesting a general fitness cost associated with the mlo virulence phenotype. We performed Illumina-based genome resequencing and whole transcriptome shotgun sequencing (RNA-seq) experiments, which revealed candidate genes potentially associated with partial mlo virulence.

14:00 to 15:00: Dr. Jaime Prohens, Professor at Universitat Politècnica de València (UPV), Spain

Introgression breeding from wild species for crops adaptation to climate change

Humankind faces the challenge of a global increasing demand of plant products in a climate change scenario coupled with the need of a more sustainable and resource efficient agriculture. In several crops, the use of crop wild relatives (CWRs) in breeding has already demonstrated that dramatic improvements can be achieved by introgression breeding. However, CWRs represent a frequently underexploited source of genetic diversity in most crops. Instead of the conventional approach of using CWRs for breeding for specific traits when diversity cannot be found in the cultivated genepool, we argue for a new approach which we called “introgressiomics”.  This is a form of pre-emptive breeding, which consists in the mass scale development, using a combination of conventional and modern breeding tools, of cultivated plant materials and populations with introgressions from CWRs. As a first step, introgressiomics requires exploring germplasm collections for CWRs from different genepools. Interspecific hybridization and backcrossing may present challenges, although some in vitro techniques can be used to overcome them. The generation of multiple populations of advanced backcrosses and introgression lines, assisted by genomic tools, allows the swift incorporation of élite germplasm in the breeding programmes. Within the framework of an international project, we have applied the introgressiomics approach to eggplant (Solanum melongena). As a result, interspecific hybrids have been obtained with 14 wild species from the primary, secondary and tertiary genepool, and advanced backcross generations and introgression lines have been developed for a number of them. Phenotyping of these materials reveals that by using the introgressiomics approach, dramatic improvements in tolerance to abiotic stresses and other traits of interest can be achieved.


Thursday, May 23, 2019
13:00 - 15:00
WUR – Forum building
Droevendaalsesteeg 2, Wageningen