【作者】 陈金；

【导师】 张卫建；

【作者基本信息】 南京农业大学 ， 作物栽培学与耕作学， 2013， 博士

【摘要】 过去100年全球平均气温已经上升0.74℃,且未来100年全球气温仍将上升1.8-4.0℃。就中国而言,2000-2050年平均气温将升高1.2-2.0℃,冬春季即冬小麦生育期内气温上升尤为显著。温度是影响小麦生长发育的最关键因子之一,探明气候变暖对冬小麦生产的影响,对我国冬小麦生产应对气候变化和中长期粮食安全战略决策具有重要意义。至今已有的相关研究多基于模型模拟和历史资料的分析,部分试验研究也多在人工控制环境下进行,很难真实全面的反映田间实际气温升高对冬小麦的影响。为此,本文以我国冬小麦主产区为研究对象,采用历史资料挖掘和田间增温试验相结合的方法,就气候变暖对冬小麦生产的影响进行系统研究。重点分析区域内气候变化特征,产量变化特征及其与气候变化的关系,探明冬小麦生长对气候变暖的实际响应和适应特征及其生物学机制,拟为气候变暖背景下冬小麦品种改良和种植区域调整提供理论与技术支撑。本文主要结论如下：(1)1989-2009年区域内冬小麦生长季日平均气温、日最高气温和日最低气温分别以0.67℃decade-1、0.55℃decade-1和0.52℃decade-1的速度升高(P<0.05)且升温幅度呈现显著的区域差异。根据积温法理论推算,1989-2009年间,全区域冬小麦播种期以0.8d decade-1(P<0.01)的速度推迟,但开花期和成熟期分别以4.1ddecade-1和5.1d decade-1(P<0.01)的速度提前。全区域内冬小麦光温生产潜力以71.7kg hm-2year-1的速度极显著增加(P<0.01),其增幅呈现由东向西递增趋势,以西北部增幅最高,达150kg hm-2year-1。(2)依据1989-2009年地市级农业统计数据和气象数据,分析地市级实际产量、滑动平均法去趋势产量和一次回归法去趋势产量变率与气象因子的变率的关系,发现气候变暖显著影响冬小麦产量,但产量对不同的气象因子的响应不一致。其中,以日最低气温与产量变化相关性最高。在地级市尺度上,根据实际产量、滑动平均法去趋势产量和一次回归法去趋势产量变率估算,在未来的气候变暖背景下,日最低温升高1℃,冬小麦产量分别以538.0kg h m-2a-1、21.7kg h m-2a-1和33.5kg h m-2a-1的速率增加。同时,通过分析16个中长期定位试验点产量与气象因子的关系也发现了相似的规律。(3)三年的夜间增温试验结果表明,镇江、河南、徐州和石家庄冬小麦开花期分别平均提前了3d、5d、6d和7d,成熟期分别提前了1d、2d、1d和2d,但花后生育期长度分别延长了2d、3d、5d和5d。同时,夜间增温下,镇江、河南、徐州和石家庄冬小麦地上部总生物量较对照3年平均分别增加了20.8%、19.6%、12.3%、18.5%,产量3年平均分别提高了8.9%、13.9%、11.8%和11.7%,均达到统计显著水平(P<0.05)。分析产量构成发现,冬小麦产量提高主要归功于千粒重和每穗粒数的增加,其中,夜间增温处理下镇江、河南、徐州和石家庄冬小麦千粒重3年平均分别增加了4.7%、6.0%、6.7%和7.1%(P<0.05)。区域分析表明,夜间增温下,生育期长度变化和冬小麦生产力变化与背景气温负相关,背景温度越低,变化幅度越大。(4)试验发现,夜间增温显著提高旗叶与花后总绿叶面积,其增加幅度分别为38.3%和12.6%(P<0.05)。与此同时,旗叶的净光合速率和呼吸速率也分别提高了2.8μmol CO2m-2s-1和0.6μmolCO2m-2s-1。夜间温度升高,冬小麦叶片可溶性糖和淀粉含量在夜间较对照下降幅度更大,但白天增加幅度亦更大,且白天增加幅度高于夜间下降幅度,说明在夜间温度升高条件下,冬小麦叶片由于夜间呼吸的增加,存在光合过补偿现象。(5)夜间增温下,4个试验点冬小麦总淀粉和直链淀粉含量变化趋势一致。镇江和河南冬小麦总淀粉含量较对照分别平均降低了5.6%和1.4%,直链淀粉分别降低了9.3%和23.4%；但徐州和石家庄冬小麦总淀粉含量分别增加了7.7%和6.4%,直链淀粉增加了11.6%和9.3%。夜间温度升高趋向于降低籽粒蛋白质含量,但单位面积蛋白质总产量呈现递增趋势。在2008-2009生长季,夜间增温使镇江、河南、徐州和石家庄冬小麦籽粒蛋白质含量较对照分别下降了0.7%、0.7%、8.4%和7.6%,但籽粒蛋白质产量较对照分别增加了10.3%、4.7%、1.5%和5.5%。(6)近60年我国育成并推广的冬小麦新品种生育期和春化过程呈缩短趋势,抗寒性下降。北部冬麦区育成品种生育期长度以1.00d decade-1缩短,冬性小麦品种比例下降,弱冬性小麦品种比例增加；黄淮麦区育成品种生育期基本稳定,但冬性和偏春性小麦品种比例下降,弱冬性和春性小麦品种比例增加；长江中下游冬麦区育成品种生育期长度以0.41d decade-1的速度缩短,春性小麦品种比例增加,弱冬性和偏春性小麦品种比例下降。根据1992-2009年田间观察数据分析,区域内冬小麦播种-抽穗和全生育期天数以0.66d decade-1和0.42d decade-1的速度缩短,但抽穗-成熟天数以0.28d decade-1的速度延长,且播种-抽穗、全生育期天数生育期内气温呈显著负相关,抽穗-成熟天数与日平均气温和日最高气温呈负相关,但与其日最低气温呈正相关。区域差异分析表明,与1990s相比,2000s播种-成熟缩短天数呈现由东至西递增趋势。更多还原

【Abstract】 The global mean air temperature has increased0.74℃in the past100years and is projected to rise about1.8-4.0℃in the next100years. In China, relevant forecast reports that the mean air temperature will increase2.3-3.3℃and the temperature during winter wheat growth season which includes winter and spring will significantly rise. Temperature is one of the most important factors on the growth of wheat. To address the response of climate warming on winter wheat production and make long-term food security strategy decision, it is great significance to study the responses of wheat production to the climate warming. So far, these researches were mostly based on the model projection and historical data analysis, and parts of experiments also were conducted under artificial controlled conditions. These results were difficult to understand real and comprehensive effects of actual warming on winter wheat in the field. Therefore, the main winter wheat production areas in China as the research object, winter wheat response and adaptation to climate warming and regional difference were systematically investigated using historical data mining, and field warming trials combined in main region of winter wheat in China. In this paper, characteristics of climate change, yield variation and its relationship with climate change were analyzed, and the actual response and adaptation characteristics of winter wheat growth to climate warming, and its biological mechanism was ascertained. It will provide theoretical and technical support for winter wheat variety improvement and adjustment of plant area under climate warming. Main results in this paper are as follows:(1) In1989-2009, daily mean temperature, daily maximum and minimum temperature of winter wheat growing season had significantly increased by0.67,0.55and0.52℃decade-1during winter wheat growing season in the study area, and there were differences in different areas. According to theoretical calculations using the accumulated temperature method, date of sowing was delayed by0.8d decade-1. However, the date of anthesis and maturity were advanced by4.1and5.1d decade-1during1989-2009, respectively (P 0.01). The light-temperature potential productivity of winter wheat was enhanced by71.7kg ha-1year-1in the study area from1989to2009, and there was an advance trend of increase from the east to the west. In the northwest of study area, increase of the light-temperature potential productivity was the highest (150kg ha-1year-1).(2) Based on agricultural statistical and meteorological data from1989to2009at prefecture-level cities, the relationships among actual yield trend, de-trend yield trend using a3-year moving average method, de-trend yield trend using quadratic regression method at prefecture-level cities and main climate factors anomal were analyzed. The results indicated that winter wheat yield changed by climate warming, and responses of yield to different meteorological factors were not similar. Specifically, the relationship between daily minimum temperature and yield trend was the highest, and there were regional differences. According to a regression analysis of the anomalies of actual yield trend, de-trend yield trend using a3-year moving average method and de-trend yield trend using quadratic regression method at prefecture-level cities prefecture-level cities, a1.0℃increase in daily minimum temperature would lead to an increment of538.0,21.7and33.5kg ha-1year-1in the study area, respectively. Meanwhile, the similar result was found by analysis of relationship between yields of16mid-long term experiment sites and meteorological factors.(3) Averaged on three years, nighttime warming advanced the anthesis and maturity by3,5,6,7d and1,2,1,2d at Zhengjian, Henan, Xuzhou and Shijiazhuang sites, respectively, but prolonged the length of post-flowing stage by2,3,5and5d. Meanwhile, the aboveground biomass and grain yield at Zhengjian, Henan, Xuzhou and Shijiazhuang sites were significantly higher by20.8,19.6,12.3,18.5%and8.9,13.9,11.8,11.7%in the nighttime warming plots than in the control, respectively. By analyzing the yield components, the results indicated that yield increase was mainly due to higher1000-grain weight and grain number per spike in the nighttime warming plots than in the control. Warming enhanced1000-grain weight by4.7,6.0,6.7and7.1%(P<0.05) compared with control treatments at Zhengjian, Henan, Xuzhou and Shijiazhuang sites, respectively. Meanwhile, negative regressions between background temperatures of site, and variations of length of growing period and productive were found under nighttime warming condition. The lower the background temperature, the greater the variations of length of growing period, and productive to nighttime warming.(4) Compared to control treatments, nighttime warming significantly increased flag area and total green area by38.3and12.6%, respectively. Flag leaf photosynthesis and nighttime respiration rates were higher in the nighttime warming plots than in the control plots by2.8and0.6umol CO2m-2s-1, respectively. Meanwhile, depletion of soluble sugar and starch for top three leaves were increased by nighttime warming at nighttime, but it was higher accumulation at daytime than depletion at nighttime. These results implied that the stimulations of nighttime respiration and carbohydrate depletion could be overcompensated by nighttime warming led to the photosynthetic compensation mechanism.(5) Under nighttime warming condition, responses of total starch and amylose content in grains of winter wheat to nighttime warming were similar at each site. Averaged on two growing seasons of2007-2008and2008-2009, the nighttime warming plot resulted in5.6and9.3%lower total starch and amylose, respectivly at Zhengjian, and1.4and23.4%at Henan than that of control plot. On the contrary, these were higher by7.7and9.3%, respectively at Xuzhou, and by6.4and9.3%at Shijiazhuang. Nighttime warming declined protein contents in the winter wheat grain, but increased protein yield per unit area. Averaged on two growing seasons of2007-2008and2008-2009, protein content was lower by0.7,0.7,8.4and7.6%in the nighttime warming plots than in the control plot at Zhengjian, Henan, Xuzhou and Shijiazhuang sites respectively, and protein yield per unit area was higher by10.3,4.7,1.5and5.5%.(6) Nearly60years, the growth period and vernalization process of breeding new winter wheat varieties were shortened and cold resistance of varieties became week. For Northern winter wheat area, length of breeding varieties period shortened by1.00d decade-1and the proportion of winterness varieties declined, the proportion of weak winterness varieties increased. In case of Huang-Huai winter wheat area, length of breeding varieties period basically remained stable and the proportion of winterness and weak springness varieties became fewer and fewer, but the proportion of weak winterness and weak springness varieties became more and more. For Yangtze River winter wheat area, length of breeding varieties period shortened by0.41d decade-1and the proportion of springness varieties reduced, the proportion of weak winterness and weak springness varieties enhanced. In addition, length of sowing to anthesis and whole period shortened by0.66and0.42d decade-1, but length of anthesis to maturity increased by0.28d decade-1according to field observation in the whole study area from1992to2009. Meanwhile, during growing stage negative regressions were found among the length of sowing to anthesis and maturity, and temperature. There were negative regressions among the length of anthesis to maturity, and daily average temperature and maximum temperature, but there were positive regressions between the length of anthesis to maturity and daily minimum temperature. Compared with1990s, shortage length of sowing to maturity trended to increase from east to west in2000s.更多还原