Research objectives of the Station
The research activity of the Station is focused on research of resistance against diseases in apples and on breeding of scab resistant and powdery mildew tolerant apple varieties. Breeding for resistance to these diseases has a high priority throughout the world in view of minimizing the use of chemicals in fruit production. The most frequent problems of commercialization of resistant varieties are unsatisfactory organoleptic fruit qualities. In our program started in 1966 we use hybrids with Vf resistance against scab from Malus floribunda and cultivars with polygenic tolerance against scab and mildew.
A series of varieties with a broad spectrum of ripening time, fruit qualities and growing properties has been released from this program. The varieties are protected by Plant Variety Rights in Czech Republic, Switzerland and in the European Union and by United States patent.
Our ongoing research is focused on further improvement of commercial qualities of resistant varieties and on a combination of Vf resistance with tolerances against scab encoded polygenically in order to render scab resistance more durable. In relation to these objectives genetic sources homozygous in the gene Vf are created using molecular markers for their identification and attemps are made to find molecular markers for other types of scab resistance.
Propagation of the new varieties requires a licence agreement and payment of royalties. The varieties are grown for commercial fruit production in countries of the European union and in the USA mainly as organic apple production. The mostly grown is at the present time the variety Topaz and its mutation Red Topaz. The yellow coloured varieties Opal®, Orion, Luna and Sirius are introduced into the market in Europa and maditerranean countries under the Golden Sunshine Line ® (GSL) marketing concept of the German society webfruit GmbH. In North America they are licensed to Varieties International LLC Dundee, OR97115.
The Station is also involved in breeding of disease resistant varieties with compact columnar growth habit using varieties derived from the "Wijcik" mutant of McIntosh. One variety, Sonet, is protected in Czech Republic and several varieties were applied for Community Plant Variety Rights in the European Union (Cactus, Goldlane, Moonlight, Redlane, Redspring, Rhapsodie, Rondo, Sonate, Sunlight). These varieties are commercialized in the European Union mainly for home gardens.
The inventors of the varieties are employees of the Institute and the latter is the owner of the varieties.
Selected varieties to which plant protection in the European union or in the USA has been granted since the year 2005:
Group of plant-pathogen inetractions
Plant-pathogen interaction leads to activation of specific genes followed by synthesis of proteins or enzymes engaged in host defense reactions. An important process of gene expression regulation involves chemical modifications of specific residues on histones that remodel chromatin from a tightly coiled, functionally repressive conformation (heterochromatin) to a relatively relaxed structure (euchromatin) that is readily accessible to transcription factors and hence biologically active. A vital step in understanding how genes are expressed or are not expressed (silent) was discovery of histone methylation, an initiating event in silencing of genes, and histone methyl transferase (HMT), the enzyme that drives methylation, is therefore of great topical interest. A conserved region of some 130 amino acid residues, termed the SET domain, is the core element of HMT.
The basic research of the laboratory is concerned with functional characterization of SET domain in Arabidopsis thaliana and is mainly focused on two recently discovered HMT isoforms in K23 mutant. These two isoforms, termed α and β, are apparently created by alternative RNA splicing.
The current work is concentrated on characterization of the functions of HMT K23 and of two additional Arabidopsis SuvR SET domain subfamily members and on determination if there is any interaction between the two isoforms, α and β. Since the domain architecture of HMT K23 closely parallels that of DIM-5 of Neurospora, the only HMT in this organism, the possible complementation with Neurospora mutants DIM-5 is also studied. If these experiments are successful, this approach can be used as a rapid screen for HMT activity of other plant (or animal) SET proteins.
In the field of applied research, the laboratory is involved in molecular biology of resistance against apple scab caused by the fungus Venturia inaequalis.