Due to global climate changes, the growth of ornamental plants will be influenced by warming episodes in winter. The purpose of this examination was to estimate the effect of three levels of irrigation regimes on the freezing tolerance of acclimated viola (Viola × wittrockiana ‘Iona Gold with Blotch’). This experiments included three irrigation regimes (80, 60 and 40% FC) with different temperatures (20, 0, − 3, − 6, − 9, − 12, − 15, − 18, − 21 and − 24 °C). After irrigation regimes, proline and carbohydrate contents were recorded. Then, plants were moved to the thermo-gradient freezer and electrolyte leakage percentage (EL %), survival percentage (SU %), lethal temperature resulting in 50% mortality according to the electrolyte leakage percentage and survival percentage (LT50el and LT50su) were evaluated. The carbohydrate and proline content increased when plants were under drought stress conditions. Electrolyte leakage percentage across three levels of irrigation treatment increased by lowering the temperature; this increase at − 24 °C was fivefold more than the control. Survival percentage in all treatments was not affected in the thermal ranges of 0 to − 9 °C, but decreasing the temperature to − 24 °C resulted in the full loss in all treatments. Vegetative growth and reproductive components were significantly affected by drought and freezing temperature treatments. Dry weights of different parts of plants reached peak values when plants were under 60% FC at 0 °C condition. A negative correlation between LT50el with carbohydrate and proline levels was found and drought treatment significantly increased freezing tolerance (lower LT₅₀) in plants grown under 60% FC compared to other treatments.

由于全球气候变化，冬季升温会影响观赏植物的生长。该检查的目的是评估三种灌溉方式对中提琴（Viola×wittrockiana）的耐冻性的影响。“ Iona Gold with Blotch”）。该实验包括三种灌溉制度（80、60和40％FC），它们具有不同的温度（20、0，-3，-6，-9，-12，-15，-18，-21和-24°C）。灌溉制度后，记录脯氨酸和碳水化合物含量。然后，将植物移至温度梯度冷冻机中，并根据电解质泄漏率和存活率（LT50el和LT50su）评估电解质泄漏率（EL％），存活率（SU％），致死温度，导致50％的死亡率。 。当植物处于干旱胁迫条件下时，碳水化合物和脯氨酸含量增加。通过降低温度，在三个灌溉处理水平上的电解液泄漏百分比都增加了；在− 24°C时，这种增加是对照的五倍。在0至-9°C的温度范围内，所有处理的存活率均不受影响，但将温度降至-24°C则导致所有处理的全部损失。营养生长和生殖成分受到干旱和冷冻温度处理的显着影响。当植物在0°C条件下处于60％FC时，植物不同部位的干重达到峰值。发现LT50el与碳水化合物和脯氨酸水平之间呈负相关，干旱处理显着提高了冷冻耐受性（LT较低）当植物在0°C条件下处于60％FC时，植物不同部位的干重达到峰值。发现LT50el与碳水化合物和脯氨酸水平之间呈负相关，干旱处理显着提高了冷冻耐受性（LT较低）当植物在0°C条件下处于60％FC时，植物不同部位的干重达到峰值。发现LT50el与碳水化合物和脯氨酸水平之间呈负相关，干旱处理显着提高了冷冻耐受性（LT较低）与其他处理相比，在60％FC下生长的植物中的₅₀）。