Wu Lu, Yu Weidong, Cheng Chen, Feng Liping, Yan Jintao, Zheng Dawei, Yang Feiyun
China Meteorological Administration Training Center, Beijing, China.
College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.
Front Plant Sci. 2024 Oct 17;15:1419381. doi: 10.3389/fpls.2024.1419381. eCollection 2024.
Winter wheat ( L.) is a crucial crop that guarantees food supply in the North China Plain (NCP). As the frequency of extreme cold events increases, it is necessary to explore the freezing resistance of different wheat varieties in order to clarify planting boundaries and help with risk assessment. In this study, 2-year controlled experiments were conducted to explore the effect of freezing temperatures ( ) and freezing durations on three winterness types. A set of indexes were used to characterize the subfreezing stress on wheat tiller, leaf, and final yield. Logistical regressions were used to quantify the temperature threshold for 10%, 30%, and 50% of freezing injury. The results showed that the lower temperature threshold of tiller (LT) varied from -9.6 to -15.9°C, -10.7 to -19.1°C and -11.4 to -21.2°C for LT, LT, and LT, respectively. The difference between LT and yield loss (YL) indexes reduced with decreased winterness types and was -0.1 to 3.4°C, -0.7 to 2.1°C, and 0.3 to 0.9°C higher compared with YL thresholds for winterness, semi-winterness, and weak-winterness types, respectively. The average minimum soil temperature was 7.5, 4.8, and 4.2°C higher than for 1-, 2-, and 3-day treatment, respectively. Soil effective negative accumulated temperature hours (TSE) ranged from 6.9 to 12.0, 48.4 to 6.9, and 84.7 to 106.9°C·h for 10%, 30%, and 50% tiller mortality, respectively. Freezing treatment with < -12, -9, and -8°C obviously decreased leaf Fv/Fm for the three varieties and Fv/Fm declined obviously after 5 days of recovery under field conditions. Our results provided multiple indexes for quantifying subfreezing damage in practical wheat production and could shed light on future risk assessment.
冬小麦（L.）是保障华北平原粮食供应的关键作物。随着极端寒冷事件发生频率的增加，有必要探究不同小麦品种的抗冻性，以明确种植界限并助力风险评估。本研究开展了为期两年的对照试验，以探究冷冻温度（ ）和冷冻持续时间对三种冬性类型的影响。使用一组指标来表征小麦分蘖、叶片和最终产量的亚冰点胁迫。采用逻辑回归来量化10%、30%和50%冻害的温度阈值。结果表明，分蘖的较低温度阈值（LT）对于冬性、半冬性和弱冬性类型分别在-9.6至-15.9°C、-10.7至-19.1°C和-11.4至-21.2°C之间变化。LT与产量损失（YL）指标之间的差异随着冬性类型降低而减小，与冬性、半冬性和弱冬性类型的YL阈值相比，分别高出-0.1至3.4°C、-0.7至2.1°C和0.3至0.9°C。1天、2天和3天处理的平均最低土壤温度分别比 高7.5°C、4.8°C和4.2°C。土壤有效负积温小时数（TSE）对于10%、30%和50%分蘖死亡率分别在6.9至12.0°C·h、48.4至6.9°C·h和84.7至106.9°C·h之间。对于三个品种，当温度< -12°C、-9°C和-8°C时进行冷冻处理明显降低了叶片Fv/Fm，并且在田间条件下恢复5天后Fv/Fm明显下降。我们的结果为实际小麦生产中量化亚冰点损害提供了多个指标，并可为未来风险评估提供参考。
