Department of Plant Science, The Pennsylvania State University, University Park, PA, 16802, USA.
Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, 44691, USA.
Planta. 2019 Aug;250(2):495-505. doi: 10.1007/s00425-019-03183-6. Epub 2019 May 14.
This study demonstrated that freeze-induced hydraulic failure varies between two Vitis species that have different xylem vessel frequency and grouping. However, seasonal recovery of young grapevines was similar between the species. Sub-freezing temperatures after budburst represent a major threat for the cultivation of fruit crops in temperate regions. Freeze stress might disrupt xylem hydraulic functionality and plant growth; however, it is unclear if hydraulic traits influence the ability of woody plants to cope with freeze stress. We investigated if a grapevine species (Vitis hybrid) with earlier budburst had anatomical traits that cause higher freeze-induced hydraulic failure but also confer a greater ability for seasonal recovery compared to a Vitis vinifera species. Two-year-old Vitis hybrid and vinifera grapevines were container-grown outdoors, assigned to either a control (n = 40) or a freeze-stressed (n = 40) treatment and exposed to a controlled-temperature (- 4 °C) freeze stress shortly after budburst. We found that the Vitis hybrid had greater stem-specific hydraulic conductivity (K) and was more vulnerable to freeze-induced embolism compared to the V. vinifera species, which exhibited a less efficient but safer water transport strategy. Seventy-two hours after the freeze stress, K of freeze-stressed V. vinifera was 77.8% higher than that of the control, indicating hydraulic recovery. While the two species did not differ in xylem vessel diameter, Vitis hybrid exhibited higher vessel frequency and percentage of vessel grouping, which could explain its higher K and greater freeze-induced K loss compared to the V. vinifera vines. While the two species varied in the short-term hydraulic response, they exhibited similar and full hydraulic and vegetative recovery by midseason, including bud freeze tolerance during the following fall and mid-winter.
本研究表明，具有不同木质部导管频率和导管组合的两个葡萄品种之间，冰冻诱导的水力失效存在差异。然而，两个品种的幼葡萄树在季节性恢复方面相似。芽膨后出现的亚冷冻温度对温带地区水果作物的种植构成了重大威胁。冰冻胁迫可能会破坏木质部水力功能和植物生长；然而，水力特性是否会影响木本植物应对冰冻胁迫的能力尚不清楚。我们调查了一个芽膨较早的葡萄品种（杂种葡萄）是否具有更高的冰冻诱导水力失效的解剖学特征，但与葡萄品种相比，它也赋予了更大的季节性恢复能力。将 2 年生的杂种葡萄和葡萄藤在户外容器中种植，分为对照（n = 40）和冰冻胁迫处理（n = 40），在芽膨后不久经历受控温度（-4°C）的冰冻胁迫。我们发现，与葡萄品种相比，杂种葡萄具有更大的茎特异性水力传导度（K），并且更容易受到冰冻诱导的栓塞影响，而葡萄品种则表现出效率较低但更安全的水分运输策略。在冰冻胁迫后 72 小时，受冰冻胁迫的葡萄品种的 K 比对照高 77.8%，表明水力恢复。虽然两个物种在木质部导管直径上没有差异，但杂种葡萄表现出更高的导管频率和导管分组百分比，这可以解释其与葡萄品种相比具有更高的 K 和更大的冰冻诱导 K 损失。虽然两个物种在短期水力响应方面存在差异，但它们在中期表现出相似且完全的水力和营养体恢复，包括在下一个秋季和仲冬期间芽的抗冻性。
