Data_Sheet_1_Phenotypic variation from waterlogging in multiple perennial ryegrass varieties under climate change conditions.pdf

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 common varieties (one diploid and three tetraploid) grown in atmospherically controlled growth chambers during two months of peak growth. The climate treatments compare ambient climatological conditions in North-western Europe to the RCP8.5 climate change scenario in 2050 (+2°C and 550 ppm CO2). At the end of each month multiple phenotypic plant measurements were made, the plants were harvested and then allowed to grow back. Using image analysis and principal component analysis (PCA) methodologies, we assessed how multiple predictors (phenotypic, environmental, genotypic, and temporal) influenced overall plant performance, productivity and phenotypic responses. Long-term waterlogging was found to reduce leaf-color 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 the diploid one. The climate change treatment was found to reduce color intensities further. Flooding was found to reduce plant productivity via reductions in color pigments and root proliferation. These effects will have negative consequences for global food security brought on by increased frequency of extreme weather events and flooding. Our imaging analysis approach to estimate effects of waterlogging can be incorporated into plant health diagnostics tools via remote sensing and drone-technology.厘清气候变化各组成要素如何影响生态系统与植被存续，对于减缓其负面影响至关重要。相较于温度与二氧化碳，气候变化引发的涝渍现象尚未得到充分研究。草地与全球粮食安全息息相关，因此尤为脆弱；其中多年生黑麦草（perennial ryegrass）广泛分布于欧洲西北部诸多易涝牧场中。本研究以四种常见的多年生黑麦草品种（1个二倍体、3个四倍体）为材料，在环境可控的人工气候箱中开展为期两个月的生长高峰期实验，探究长期涝渍对其表型响应的影响。本研究设置两组气候处理：一组为欧洲西北部的当前自然气候条件，另一组为2050年RCP8.5（典型浓度路径8.5）气候变化情景下的环境参数（升温2℃、二氧化碳浓度达550ppm）。每轮实验周期结束时，研究团队会对植株开展多项表型测定，随后收割植株并促使其重新萌发。本研究采用图像分析与主成分分析（PCA）方法，评估了多类预测因子（表型、环境、基因型及时间维度因子）对植株整体表现、生产力及表型响应的影响。研究发现，长期涝渍会降低叶片颜色饱和度；幼株呈现的紫色调为花青素（anthocyanins）积累的表征。涝渍植株的整体表现与单株产量均低于对照组，其中四倍体品种的耐受能力优于二倍体品种。气候变化处理组会进一步降低叶片颜色饱和度。涝渍会通过降低色素含量与根系增殖能力，削弱植株的生产力。此类效应将因极端天气事件与涝灾发生频率的增加，对全球粮食安全造成负面影响。本研究用于评估涝渍效应的图像分析方法，可通过遥感与无人机技术整合至植株健康诊断工具中。