In subtropical regions, low-chill stone fruit (Prunus spp.) crops have experienced the negative impacts of flooding caused by hurricanes and tropical storms. These crops are considered very susceptible to oxygen-deficient soil conditions resulting from flooding. We investigated physiological and biochemical responses to flooding of six Prunus spp. rootstocks including Flordaguard, are commonly used as a rootstock for peaches in the subtropics. Flooding caused a reduction in net CO₂ assimilation (A), stomatal conductance (gs), and leaf nutrient contents in all rootstocks tested. Antioxidant activity, osmolyte concentrations, lipid peroxidation, and reactive oxygen species (ROS) activity increased in response to flooding in all rootstocks. After exposure to flooding, rootstocks MP-29 and R5064-5 had higher A, gs, antioxidant activities, and osmolyte concentration, and lower lipid peroxidation and ROS activity than the other rootstocks. These two rootstocks also had higher leaf nitrogen (N), phosphorous (P), and potassium (K) contents than the other rootstocks. Although leaf iron (Fe) and manganese (Mn) contents increased in all rootstocks exposed to flooding, MP-29 and R5064-5 exhibited the lowest increases in leaf Mn and Fe concentrations. Thus, rootstocks MP-29 and 5064-5 are better suited to subtropical areas prone to flooding than the other rootstocks, including Flordaguard. In the two rootstocks that were the most tolerant of flooding, greater antioxidant activities and osmolyte concentrations appeared to efficiently mitigate oxidative damage caused by oxygen deficiency. Also, osmolyte concentration and lipid peroxidation appear to be potential indicators of sensitivity to flooding stress in Prunus rootstocks.

在亚热带地区，低冷核果类（李属）遭受了飓风和热带风暴对洪水的负面影响。这些农作物被认为极易遭受洪水造成的缺氧土壤条件的影响。我们调查了对六个李属水淹的生理和生化反应。包括Flordaguard在内的砧木在亚热带地区通常用作桃子的砧木。洪水导致CO ₂同化净量（A），气孔导度（gs），以及所有测试砧木中的叶片养分含量。抗氧化剂活性，渗透液浓度，脂质过氧化作用和活性氧（ROS）活性随所有砧木的淹水而增加。暴露于洪水后，砧木MP-29和R5064-5的A，gs较高，抗氧化剂活性和渗透液浓度，以及比其他砧木更低的脂质过氧化和ROS活性。这两种砧木还具有比其他砧木更高的叶氮（N），磷（P）和钾（K）含量。尽管暴露于水淹的所有砧木中叶铁（Fe）和锰（Mn）含量均增加，但MP-29和R5064-5的叶中Mn和Fe浓度增幅最低。因此，砧木MP-29和5064-5比其他砧木（包括Flordaguard）更适合于容易泛滥的亚热带地区。在两种最能耐受洪水的砧木中，更高的抗氧化剂活性和渗透压浓度似乎可以有效地减轻由缺氧引起的氧化损伤。也，李属砧木。