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良影响，需精准且及时地监测木薯植株对涝渍的响应。涝渍条件下，根系缺氧会降低水分吸收能力，气孔关闭则限制蒸腾作用，由于蒸发冷却作用减弱，通常会导致叶片温度升高。然而，涝渍条件下木薯叶片中上述关联的变化机制仍鲜为人知。本研究提出假说：针对不同木薯基因型，在涝渍胁迫下维持较凉的冠层对植株最优表现至关重要。本实验选取2个木薯品种，进行为期12天的涝渍处理，采用完全随机设计并设置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，这反映出气孔调控功能受损与蒸发冷却作用减弱。研究发现ΔT与光合参数间存在显著负相关关系，表明ΔT可作为低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，在涝渍胁迫下维持较凉的冠层有助于提升植株的耐涝性与存活率；ΔT可作为筛选与选育耐涝木薯基因型的实用工具。不过，后续仍需开展不同品种的对比研究，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，以验证并完善本研究的结论。