How can varieties be evaluated for registration in the context of climate change?
Climate change is a reality that affects society as a whole, and agriculture in particular. Many levers can be mobilised, including plant genetics. The Scientific Committee of the CTPS, charged with carrying out a referral on the evaluation of varieties in the context of climate change, presented the conclusions of its work to the Plenary Committee of the CTPS on 21 November. The CTPS SC recommends strengthening the CTPS’s capacity to anticipate and guide climate change, by putting in place structuring guidelines. Trials should be better characterised through envirotyping, and the data obtained in evaluations should be better exploited.
By 2050, an average temperature rise of +2 to +3°C is expected in France, with an increase in climatic hazards (drought, heat waves, late frosts, storms and hail). This climate disruption will have a number of effects on agriculture, through higher temperatures and atmospheric CO2, intensified heatwaves and drought. This could lead to a shortening of crop cycles, an increased need for irrigation to avoid crop failure, and a change in the rate of reproduction of crop pests. The combination of these stresses is still not well known. The varietal lever is one of a number of levers for action in response to climate change.
Responding to the challenges of climate change will require a shift in priorities for a large number of species, from improving yield potential to stabilising yield by improving resistance to abiotic stresses and making better use of nutrients. The challenge of resistance to biotic stresses is also being stepped up. It also seems essential to consider the contribution of plant genetic resources in adapting to climate change, as they represent a real reservoir of alleles of interest.
The different sections of the CTPS are already confronted with these different stresses linked to climate change, in particular the lack of rainfall at key stages in crop development, high temperatures and the development of pests and diseases. This raises technical difficulties in conducting trials and the relevance of morphological observations, as well as problems in validating trials.
Evaluating the ability of varieties to adapt to climate change will require the characterisation of trial environments through envirotyping. The CTPS SC proposes that the occurrence of a hazard should be considered as an event of interest and information that should be exploited, and this requires a detailed description of the environments encountered in the various trials.
The SC of the CTPS recommends strengthening the CTPS’s capacity to anticipate and guide climate change, by setting up structuring guidelines (new bonuses, choice of trial locations and conditions, changes in varietal types). In each section, the expected effects of climate change on each species should be explained, the traits affected and the traits of interest should be defined, more reflection should be given to varietal performance in terms of mean value and variance, and the notion of risk linked to the stability of varietal performance should be introduced. Trials should be better characterised through envirotyping, and the data obtained from evaluations should be better exploited. As far as possible, it is recommended that the trials set up by breeders during the selection process be used to identify interesting varietal behaviour in the face of the expected effects of climate change. In view of the effects of climate change, particularly inter-annual variations, it is important to secure the locations where DUS trials are conducted in order to produce quality data.
Adapting to climate change will require us to change the way we operate and the way we approach things. This could be an opportunity to mobilise new relationships at European level, between the different national variety registration systems and between the different examination offices.
