Raw Data

Cassava plants’ response to waterlogging must be monitored in an accurate and timely manner to mitigate the adverse effects of waterlogging stress. Under waterlogging conditions, root hypoxia reduces water uptake and stomatal closure limits transpiration, which often results in increased leaf temperature due to reduced evaporative cooling. However, how this relationship changes in cassava leaves under waterlogged conditions remains poorly known. This study hypothesized that a cooler canopy is more critical for better performance under waterlogging stress in various cassava genotypes. Two cassava cultivars were subjected to twelve days of waterlogging. The experiment was laid out in a completely randomized design with three replications. Results revealed a significant decrease in photosynthetic rate, stomatal conductance, and transpiration, and an increase in leaf temperature and ΔT, reflecting impaired stomatal regulation and reduced evaporative cooling. Strong negative correlations between ΔT and photosynthetic parameters were observed presenting ΔT as a reliable, nondestructive indicator of cassava’s physiological responses under hypoxic conditions. Findings indicate that maintaining cooler canopies may contribute to enhanced tolerance and survival under waterlogging. ΔT can be used as a practical screening tool for identifying and selecting waterlogging-tolerant cassava genotypes. However, further studies involving contrasting cultivars and additional parameters such as leaf relative water content, free water content, and leaf anatomy are recommended to validate and strengthen reported findings.

为缓解涝渍胁迫带来的不利影响，需对木薯（Cassava）植株的涝渍响应开展精准且及时的监测。在涝渍环境下，根系缺氧会降低水分吸收能力，气孔关闭则会限制蒸腾作用，而蒸腾降温作用减弱往往会导致叶片温度升高。然而，涝渍条件下木薯叶片中这种关联的变化机制仍不甚明晰。本研究提出假说：在涝渍胁迫下，相较于其他木薯基因型，维持较凉的冠层对植株获得更好的生长表现更为关键。本实验选取2个木薯品种，对其进行为期12天的涝渍处理。实验采用完全随机设计，设置3次生物学重复。结果显示，光合速率、气孔导度与蒸腾速率均显著下降，而叶片温度与ΔT则显著升高，这反映出气孔调控受损以及蒸腾降温作用减弱。研究发现ΔT与光合参数之间存在显著负相关关系，表明ΔT可作为缺氧条件下木薯生理响应的可靠无损检测指标。研究结果表明，在涝渍环境下维持较凉的冠层，有助于提升木薯的耐涝性与存活率。ΔT可作为筛选耐涝木薯基因型的实用工具，用于鉴定与选育耐涝种质。不过，未来仍需开展针对不同品种的相关研究，并补充测定叶片相对含水量、自由水含量以及叶片解剖结构等参数，以验证并进一步完善本研究的结论。