Research project Development of novel breeding technology for improved root system, drought tolerance and sustainable plant productions

General introduction

Ri breeding technology is capable of achieving both more compact growth and drought tolerance in certain (ornamental) crops. This is evident from experiments of the Rootsplus project, with apple and chrysanthemum. Ri technology puts the focus on the roots, using rhizogenic bacteria. The first objective was to obtain compact plants that need no or less treatment with chemical growth regulators. This goal was successfully achieved in both apple and chrysanthemum. Second objective was to introduce drought tolerance. Under normal conditions, the physiology of the tested Ri chrysanthemums does not differ from normal plants, but under stress conditions such as drought, these plants still appear to perform better.

Research approach

Natural strains of Rhizobium rhizogenes contain a unique Ri plasmid (including the rol genes) that allows them to transfer and incorporate the T-DNA genes lying on this plasmid into the plant genome. The result is extreme root formation (hairy roots). When these roots in turn regenerate into a plant one obtains Ri plants. The presence of the Ri genes in these plants give a typical phenotype with a more pronounced root system and more compact growth, in addition to changes in flowering and leaf morphology. These Ri plants are “pre-breeding” material and can result in commercial cultivars with a stronger root system and meet all the specific quality characteristics.

Relevance/Valorization

Ri technology had been somewhat out of the spotlight in the breeding world, since science was working primarily on more sophisticated genetic knowledge and applications. This project shows that at least two very different sustainability traits can also be obtained in plant varieties via Ri. In time, this breeding technology can therefore also help make agriculture and horticulture more resilient to drought stress. There is a clear opportunity to produce ornamental plant products that require less chemical plant growth regulators because compactness can now be "built into" the plant material.
Importantly, this research project was done in cooperation with Flemish breeding companies. The companies can immediately follow up the studied plant species in practice. This is expected to lead to the effective market introduction of the first Flemish Ri plants within a few years.

Financing

VLAIO