環境逆境使植物產生活化氧族，並造成氧化逆境。本研究探討3個甘藷品種桃園2號、西蒙1號與徐藷18號受淹水與乾旱逆境時葉片之抗氧化系統，試驗採完全逢機裂區設計，取每株完全開展之嫩葉測定抗氧化活性，不同品種之吡啉、多酚與類黃酮含量、以及還原力、掃除二苯基-苦味基團(DPPH)游離基與超氧陰離子之能力各有不同，逆境下三品種之多酚含量與掃除超氧陰離子百分比皆顯著降低，而共轭雙烯(conjugated dienes)抑制百分比顯著升高，可做為甘藷淹水與乾旱耐受性之指標，並緩和淹水與乾旱效應。
Environmental stress results in generation of reactive oxygen species in plants and causes oxidative stress. The aim of this work was to study the changes to the antioxidative system in the leaves of three sweet potato varieties, Taoyuan 2, Simon 1, and Sushu 18 as affected by flooding and drought stresses. The experimental design was completely randomized with a split plot arrangement of treatments. Young, fully expended leaves from each plant were clipped for antioxidant activity measurement. We concluded that genotypes exhibited their abilities and specificities on porphyrins, polyphenol, flavonoids, reduction power and scavenging DPPH radical and superoxide anion. The polyphenol content and scavenging superoxide anion percentage of the three sweet potato varieties under the stresses declined significantly. However, the conjugated dienes inhibition percentage increased markedly under the stresses. Inhibiting the conjugated dienes could mitigate flooding and drought stress effects and be useful as a flooding and drought-tolerant index.
