Advancing plant breeding with science

Conventional plant breeding has been going on in nature for time immemorial. In more recent centuries scientific and biological knowledge have brought rigour and direction to the process, though it can still be very much a hit-and-miss process, with parent one being crossed with parent two, and the subsequent evaluation of thousands of progenies.
As Dr Ewen Mullins, head of Teagasc’s crop science department, outlined at the Teagasc’s National Tillage Conference, this process can deliver some desirable traits to be bred for commercial production. Undesirable traits also come through, which obviously have no benefits in terms of yield, disease resistance or growth, or environmental resilience. The entire process can take years, even decades to deliver viable, improved plant varieties with high value to the breeder and grower.

New genomic techniques

While the EU has turned its back on genetic modification to advance plant breeding, there are other technological breeding developments which do not involve cross species or variety breeding techniques and which have found favour with the European regulatory system. These new genomic techniques (NGTs) have the ability to deliver an updated version of an existing variety with enhanced traits in a faster and more precise manner, Dr Mullins explained. The critical fact, from a regulatory viewpoint, is that no crossing is involved with other varieties. Genome editing is advancing through several approaches, most notable CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats), and CRISPR-associated protein 9. Among the techniques involved is direct genome editing, allowing a targeted approach to developing beneficial novel traits in plants, as well as cisgenesis, which acts by editing/disrupting what is already in the plant genes. No new DNA is introduced into the target variety.

Advancing competitiveness in plant breeding

The good news around all this is that the European Commission is positively disposed towards the further development and practical application of this science. Apart from the fact that it does not involve any genetic modification through the introduction of new DNA from other plant varieties, there is the added impetus to regain the competitiveness lost through the EU’s renunciation of genetic modification. Three years ago, the Commission commenced the process of legislating for NGTs, so that the framework is now in place for NGT-derived plants. This will be fully effective in two years’ time. Dr Mullins explained the ‘nuts and bolts’ of the regulatory process. It distinguishes between two categories (NGT category I and II). NGT-derived plants and progeny developed through category I are recognised as conventional varieties. This is a hugely progressive development for plant breeding across the EU.

Testing the technology

The essential question that Dr Mullins asked and answered relates to whether NGTs actually work. Research at Teagasc and elsewhere confirms the efficacy of the technology. Photographs of Desiree potato plot trials carried out at the Oak Park crop research centre provided graphic evidence of high levels of blight resistance in the NGT-derived potato crops grown to harvest without spraying, compared to a conventional spraying regime of 11 sprays across the season, equally protecting the crop but with the additional spraying costs involved. There was also a control plot of the Desiree potato variety which clearly showed the severe effects of blight without either the intervention of NGTs or blight sprays.
Widespread adoption of these NGTs across plant breeding, generally, should increase the competitiveness of European crop agriculture in the years ahead. That is provided the science involved is well explained to the general public, confirming that the techniques involved are only a speeding up of conventional plant breeding and do not involve any genetic modifications, which have, in the past, unfortunately aroused suspicion and fear in the public.