Temperature Before Cold Acclimation Affects Cold Tolerance and Photoacclimation in Timothy (Phleum pratense L.), Perennial Ryegrass (Lolium perenne L.) and Red Clover (Trifolium pratense L.)

The expected temperature rise in late summer/early autumn can change the conditions for acclimation and affect the winter survival of perennial crops. This study examined the effect of the temperature just before the onset of cold acclimation (pre‐acclimation) on freezing tolerance of timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.) and red clover (Trifolium pratense L.) populations (both cultivars and breeding populations) adapted to either northern or southern parts of Norway. Using phytotron experiments, we studied whether increasing pre‐acclimation temperature delays growth cessation, affects photoacclimation and reduces freezing tolerance. Furthermore, we assessed whether these effects were related to the latitudinal adaptation of the plant material. The results showed that a rise in pre‐acclimation temperature decreased both cold acclimation capacity and photoacclimation in these species. This affected the freezing tolerance, which was reduced significantly more in northern‐adapted population of timothy and perennial ryegrass compared with southern‐adapted populations. Red clover was less affected by temperature changes than the grasses.     

驻马店冬小麦主要气候生态特征与高产关键性栽培技术研究

驻马店是河南省重要的小麦产区之一,常年种植面积在66.67万hm2左右,占全市粮食总面积112万hm2的59.5%,小麦总产量稳定在40亿kg以上,占河南省的1/8左右。驻马店的小麦生产在保障河南省乃至全国粮食安全中占据着举足轻重的位置。驻马店所处的地理位置特殊,其气候生态条件和豫北高产地区有明显差异,形成小麦产量三因素中的穗粒数与千粒重明显偏低,限制了小麦单产的提高,夺取高产难度明显较大。2004年以来,小麦公顷产量由5670 kg提高到目前的6850.5 kg,增长幅度较大,但是年度间存在着产量水平忽高忽低的不稳定性和不平衡性,迫切需要研究出一套适合驻马店小麦生态条件下的高产栽培技术体系,为驻马店小麦高产、稳产和粮食核心区建设提供技术支撑。     

气候变化对椰心叶甲在中国适生区的影响

为明确椰心叶甲在中国的潜在适生区,降低椰心叶甲入侵造成经济和生态损失,本研究以CLIMEX软件和椰心叶甲的生物学资料为依据,结合ArcGIS反距离加权插值分析功能,利用历史气候数据(1981—2010年)和模拟未来气候数据(2071—2100年),分析气候变化对椰心叶甲在中国的潜在适生区的影响。结果表明:在历史气候条件下,椰心叶甲主要分布于中国的南部地区,高度适生区分布面积最大。在未来气候条件下,椰心叶甲在国内适生区总面积增加,适生区具有北移的趋势。本研究可为椰心叶甲的管理防控提供一定的理论依据。     

气候变化对呼伦贝尔草地地上生物量的影响

基于温、压、湿、风等主要气象资料,结合生长季逐月的地上生物量实测数据,分析气候变化及气候年型对牧草产量形成的影响,结果表明:(1)两站降水量呈波动变化,无明显的变化趋势;(2)额尔古纳和鄂温克的年均气温呈显著升高的趋势,气温倾向率分别为0.348℃/10 a、0.444℃/10 a,增温速率均明显高于同期中国东北地区,其中,鄂温克的增温速率高于中国增温最迅速的青藏地区;(3)额尔古纳和鄂温克潜在蒸散量呈波动升高的趋势;(4)两站湿润度呈显著的波动下降趋势,气候呈较明显的变干燥趋势;(5)湿润状况影响两站地上生物量形成,气候偏旱年草原地上生物量的形成会受到显著的抑制,两站草地地上生物量均与当月及上个月的湿润度指数呈线性回归关系。     

Impact of waterlogging and temperature on autumn growth,hardening and freezing tolerance of timothy (Phleum pratense)

Precipitation has generally increased in Norway during the last century, and climate projections indicate a further increase. The growing season has also become longer with higher temperatures, particularly in autumn. Previous studies have shown negative effects of high temperatures and, depending upon temperature conditions, contrasting effects of waterlogging on hardening capacity of timothy. We studied effects of waterlogging on seedlings of timothy (Phleum pratense, cv. Noreng) under three pre-acclimation temperatures: 3°C, 7°C, 12°C, and in autumn natural light in a phytotron at Holt, Tromsø (69°N). After temperature treatments, all plants were cold acclimated at 2°C for three weeks under continued waterlogging treatments. Freezing tolerance was determined by intact plants being frozen in pots at incremental temperature decreases in a programmable freezer. Waterlogging resulted in a higher probability of death after freezing, and a significantly reduced regrowth after three weeks at 18°C, 24 hrs light in a greenhouse. Increasing pre-acclimation temperatures also had a clear negative effect on freezing tolerance, but there was no interaction between temperatures and waterlogging. The results indicate that waterlogging may have negative implications for hardening of timothy and may contribute to reduced winter survival under the projected increase in autumn temperatures and precipitation.     

本溪山区旱柳物候变化特征及其对气候变化的响应

为了探讨本溪山区气候变化对木本植物物候的影响,利用1980—2012 年国家农业气象本溪县观测站旱柳物候期资料和气温、降水、日照等资料,运用线性倾向率和趋势系数等分析方法,研究了本溪山区旱柳物候期对气候变化的响应。结果表明：在近33 年本溪山区气温呈明显的升温趋势变化,升温速率为0.45℃/10 a,降水和日照呈波动性减小趋势变化,降水量波动幅度较大,最大降雨量与最小降雨量差异大。旱柳芽开放期呈明显的延后趋势变化,其线性倾向率为2.4 d/10 a;开花始期呈拖后趋势变化,线性倾向率为0.35 d/10 a;旱柳变色始期和落叶始期均呈显著的延后趋势,其线性倾向率分别为7.27 d/10 a和5.52 d/10 a。温度对旱柳物候影响最为显著,降水和日照对物候期的变化也有一定的影响。     

作物模型中单叶最大光合作用速率的温度响应修订

作物的光合作用对温度变化敏感, 其温度依存性随品种、生长环境的变化而改变。基于光效率模型的作物生长模型, 在应用中很少对光合作用的温度影响参数值进行订正, 且在全生育期使用相同的参数值, 难免会增加干物质模拟的误差。为此, 本文以ORYZA2000模型为例, 提出了一种修订光合作用温度影响参数值的方法。为确定方法的有效性, 结合2012年和2013年水稻品种两优培九的温度梯度控制实验, 首先利用抽穗开花期光合作用观测曲线提取了不同温度水平的光合作用参数值, 然后结合Arrhenius方程和Peaked方程建立了温度敏感性参数的温度影响方程。将这些方程代入机理性光合作用模型, 模拟了单叶最大光合作用速率与温度的曲线关系。最后, 以归一化后的曲线关系修订作物模型参数值, 并利用两年地上部分生物量(WAGT)观测值对其验证。结果显示, 两优培九单叶最大总光合作用速率随温度的变化关系不同于ORYZA2000的默认设置, 修订后的最适温度为38~40°C, 高于默认值。在10~20°C的低温段, 修订后的温度影响系数低于默认值。从WAGT模拟值的相对误差看, 修订后较修订前平均降低约3.3%。本研究为改进干物质模拟精度和分析不同品种光合作用的温度依存性提供了重要参考。     

庆阳市气候四季变化分析及对作物种植的影响

应用中国气象局2012年发布的气候季节划分标准QX/T152-2012,利用庆阳市8站1981——2016年的逐日平均气温资料对庆阳市气候四季进行了划分,得出该区常年气候分为无夏季区和四季分明区。入春时间在4月中旬末至下旬初,西南早东北迟;入夏时间(四季分明区)在6月底至7月下旬,西北早中南迟;入秋时间在7月中旬末至8月中旬,东早西迟;入冬时间在10月中旬末至下旬初,东北早西南迟。采用线性相关分析法对四季分明区的入季日期进行分析得出：入春、入夏日期逐年呈现提前趋势,入冬日期呈现推后趋势,秋季持续天数呈现延长趋势,冬季持续天数呈现缩短趋势。为应对气候变化,该区近年来调整种植结构,引进了耐寒抗旱的藜麦,扩大紫花苜蓿的种植,发展畜牧业,大力发展苹果产业,加大设施农业投入。     

小兴安岭红松苗木物候期变化特征及气象影响因子分析

为了探究红松苗木物候期的变化规律,为适时播种、采种、造林、培育等林业生产提供科学依据。利用1991—2014 年小兴安岭红松苗木物候期资料及同期气候资料,采用相关分析及最优子集回归方法,分析探讨了红松苗木物候期对气象条件的响应。结果表明：（1）红松苗木芽开放始期、新梢木质化盛期有所推迟,展叶始期和新枝形成盛期都有提前趋势,整个生长季延长。（2）除芽开放始期和顶芽形成盛期外,其他物候期与期间的日照时数呈显著正相关;顶芽形成盛期与气温呈显著负相关;≥10℃积温和日最低气温是影响整个生长期长短的2 个主要影响因子,其次是日照时数和平均气温。利用最优子集回归方法建立了红松苗木物候期与气象要素的回归方程。     

Carbon Isotope Discrimination, Leaf Ash Content and Grain Yield in Bread and Durum Wheat Grown under Full-Irrigated Conditions

Integrative physiological criteria, such as carbon isotope discrimination (Δ) and (mineral) ash content (m_a) have been found to be very useful, under drought conditions, to elucidate the association between yield gains and variation of photosynthesis‐related traits and orientate future breeding efforts. Information on this association is scarce under irrigated conditions. The relationships between Δ, m_a and yield were studied in bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. var. durum) under optimal (drip) irrigation in the arid conditions of north‐west Mexico. Carbon isotope discrimination was analysed on leaves at booting stage and anthesis and on grain at maturity, whereas ash content was measured on the flag leaf at anthesis and maturity. At anthesis, there were differences between bread and durum wheat during grain filling for Δ, but not for m_a. No relationship was found between grain yield and Δ. Leaf ash content at anthesis and maturity showed a broad variability within each species and were associated with grain yield. These results suggest that ash content in leaves could be also used as predictive criteria for yield not only under drought, but also under irrigated conditions, particularly when evaporative demand is high.