运城盆地不同播期小麦春季冻害风险评价

Risk Assessment of Spring Freezing Injury of Wheat at Different Sowing Dates in Yuncheng Basin

为评价山西南部地区不同小麦品种在不同冬前积温下的春季冻害风险,明确适应当前气候变化的适宜播期和品种,分别于2017—2018霜冻发生和2018—2019霜冻不发生的两个不同气候年型,在山西运城盐湖区采用播期、品种二因子裂区试验设计,对3个不同生态类型小麦品种(济麦22、周麦18和西农529)在不同冬前积温下的春季冻害风险进行分析,研究不同小麦品种在冻害发生和不发生年型的拔节期、春季冻害及产量对冬前积温的响应。结果表明,冬前积温(播期)对小麦拔节期和春季冻害风险有显著影响,冬前积温越大(播期越早),小麦拔节越早,春季发生冻害的风险越高;品种春性越强,发生冻害的风险越高。济麦22、周麦18和西农529在3月下旬和4月上旬发生春季冻害的平均风险,皆以播期10月5日(冬前≥0℃积温为616.3℃时)最高,当播期10月20日(冬前≥0℃积温390.1℃)时,3月下旬和4月上旬发生春季冻害的平均风险明显降低。霜冻发生年,随着冬前积温的降低,小麦穗部受冻程度降低、穗发育进程延缓、相对膜透性降低、MDA含量降低、抗氧化酶活性增强,产量与冻害程度表现一致,也与冻害发生评价结果趋势一致;霜冻未发生年,产量随冬前积温的减少呈降低趋势,但是,适度降低冬前积温,两年的总产量较高。在气候变暖情境下,以冬前≥0℃积温在250~390℃时小麦产量稳定,冻害风险较低。由此可见,适度降低冬前积温是现阶段小麦应对气候变化、抗逆稳产的一条有效途径。

In order to evaluate the risk of the spring frost damage to different wheat varieties in southern region of Shanxi under different accumulated temperature before winter and define the suitable sowing date and variety of adapting the change of current climate,two-factor splitting zone test including sowing date and variety was used to analyze the risk of wheat spring freezing injury. The test were arranged in two different climatic years from 2017 to 2018(frost occurrence)and 2018 to 2019(no frost),and 3 different ecological types of wheat varieties(Jimai 22,Zhoumai 18 and Xinong 529)were sowed at different date in Yanhu district of Yuncheng. The results showed that the accumulated temperature before winter(sowing date)had significant effect on wheat jointing and the risk of wheat spring freezing injury,the higher accumulated temperature before winter(the earlier sowing date)advanced the wheat jointing stage and increased the risk of freezing damage in spring. And variety with strong spring quality had higher risk to freeze damage. The average risk of frost damage in late March and early April were the highest when the accumulated temperature(≥0 ℃)before winter was616.3 ℃,and were lowest when the accumulated temperature before winter was 390.1 ℃. In the year of frost occurrence,with the decrease of accumulated temperature before winter,the degree of freezing of wheat ear was reduced,the process of ear development was delayed,the relative membrane permeability was decreased,the content of MDA was decreased,and the activity of antioxidant enzymes were enhanced. The yield was consistent with the degree of freezing damage and the trend of evaluation of freezing damage. In no frost year,the yield showed a decreasing trend with the decrease of accumulated temperature before winter. However,the accumulated temperature before winter was moderately reduced,which had a little effect on the yield. Under the climate warming situation,the wheat yield could be more stable when the accumulated temperature(≥0 ℃)before winter was about 250~390 ℃,and the risk of freezing injury should be lower.Reducing the accumulated temperature before winter should be an effective way for wheat in environment of climate change.