S11 - Session O1 - Combat climate change with biodiversity: high throughput phenotyping to feed growth models in function of temperature

Authors: Clara Gambart *, Rony Swennen, Sebastien Carpentier

More temperature extremes, increased ambient CO 2 levels and erratic rainfall patterns impose increasing pressure on ample production areas. The yield of tropical horticultural crops with long crop cycles is heavily influenced by the basal average day temperature. Banana is such a crop with a vital economic importance. Mining the existing diversity for cultivars better adapted to the future agro-environment, will give us solutions to alleviate yield gaps. Therefore, we developed a strategy to phenotype the banana gene bank of Bioversity International under current and future climate scenario's, thereby evaluating 37 variables related to growth, mass distribution, leaf development…. Growth monitoring at 6 temperature regimes of 67 different cultivars, belonging to 19 genetic subgroups, revealed significant diversity between and even within subgroups. While the optimal average day temperature of the well-known dessert banana is 26 °C, a diverse spectrum was observed in our dataset ranging from 21 to over 29 °C. Additional experiments showed significant correlations with physiological processes at leaf level. Optimal growth temperatures coincide with optimal temperatures of photosynthesis and stomatal conductance. Stomatal control has an enormous impact on banana growth. Cultivars with lower optimal growth temperatures show fast stomatal opening at lower temperatures, confirming the optimal colder temperature regimes but they increase their stomatal resistance sooner at higher temperatures leading to additional heat stress. As climate projections expect average day temperatures to rise by over 3 °C in the next 50 years, those cultivars will reach a danger zone. Nevertheless, 52.5 % of the screened cultivars are predicted to perform equally good or even increase their productivity in future climates. This study clearly demonstrates the potential of intraspecific biodiversity in safeguarding food production under current and future challenging climatic conditions and we encourage stakeholders to further investigate this biological treasure.