Phenotypic Variation from Waterlogging in Multiple Perennial Ryegrass Varieties under Climate Change Conditions

Abstract

Identifying how various components of climate change will influence ecosystems and vegetation subsistence will be fundamental to mitigate negative effects. Climate change-induced waterlogging is understudied in comparison to temperature and CO2. Grasslands are especially vulnerable through the connection with global food security, with perennial ryegrass dominating many flood-prone pasturelands in North-western Europe. We investigated the effect of long-term waterlogging on phenotypic responses of perennial ryegrass using four varieties grown in atmospherically controlled growth chambers (ambient vs 2050, +2°C and eCO2) during two months of peak growth. Using image analysis and PCA methodologies, we assess how multiple predictors (phenotypic, environmental, genetic and temporal) influence overall plant performance and productivity. Long-term waterlogging was found to reduce leaf-colour intensity, with younger plants having purple hues indicative of anthocyanins. Plant performance and yield was lower in waterlogged plants, with tetraploid varieties coping better than diploid ones. The climate change treatment was found to reduce colour intensities further. Flooding was found to reduce plant productivity via reductions in colour pigments and root proliferation. These effects will have negative consequences for global food security from facing extreme weather events and flooding. Our approach can be adapted as plant health diagnostics tools via remote sensing and drone-technology.