玉米杂交种丹玉34号选育及栽培技术要点

丹玉34号是丹东农业科学院以外引系H185为母本,自选系丹598为父本组配成的玉米单交种,各级试验示范结果表明:该品种具有高产、稳产、抗逆性强、生育期适中、品质优良和适应性广等特点,深受广大农民欢迎。     

基于1:50 000土壤数据库并结合PKB方法估算中国浙江省土壤有机碳储量的研究

Soil organic carbon(SOC) is an important component of farming systems and global carbon cycle. Accurately estimating SOC stock is of great importance for assessing soil productivity and modeling global climate change. A newly built 1:50 000 soil database of Zhejiang Province containing 2 154 geo-referenced soil profiles and a pedological professional knowledge-based(PKB) method were used to estimate SOC stock up to a depth of 100 cm for the Province. The spatial patterns of SOC stocks stratified by soil types,watershed(buffer analysis), topographical factors, and land use types were identified. Results showed that the soils in Zhejiang covered an area of 100 740 km2 with a total SOC stock of 831.49 × 106 t and a mean SOC density of 8.25 kg m-2, excluding water and urban areas. In terms of soil types, red soils had the highest SOC stock(259.10 × 106t), whereas mountain meadow soils contained the lowest(0.15 × 106t). In terms of SOC densities, the lowest value(5.11 kg m-2) was found in skel soils, whereas the highest value(45.30 kg m-2) was observed in mountain meadow soils. Yellow soils, as a dominant soil group, determined the SOC densities of different buffer zones in Qiantang River watershed because of their large area percentage and wide variation of SOC density values.The area percentages of various soil groups significantly varied with increasing elevation or slope when overlaid with digital elevation model data, thus influencing the SOC densities. The highest SOC density was observed under grassland, whereas the lowest SOC density was identified under unutilized land. The map of SOC density(0–100 cm depth) and the spatial patterns of SOC stocks in the Province would be helpful for relevant agencies and communities in Zhejiang Province, China.     

HBV水文预报模型在白龙江流域的应用研究

[目的]在白龙江流域武都站以上区域构建HBV水文模型,通过对区域日径流模拟研究,来评估模型在该区域的适用性。[方法]在参数敏感性分析的基础上,对模型参数进行率定和验证,并分析径流和降水量的年际变化特征。[结果](1)在率定期Nash—Sutcliffe效率系数Ens=0.65,确定性系数R2=0.74,验证期Ens=0.60,R2=0.70,HBV模型在该流域模拟精度较高,具有较好的适用性;(2)降水量与模拟径流变化趋势对应,HBV模型较好地模拟出了洪水对降水的响应过程。[结论]HBV模型可进一步用于研究气候变化对白龙江流域水资源的影响。     

小麦TaSPP基因的克隆及表达分析

为明确磷酸蔗糖磷酸酶基因(SPP)的表达特征和生物学功能,进一步了解SPP参与蔗糖生物合成的调控机制。以小麦抗旱品种晋麦47的cDNA为模板克隆出3个位于第5同源群上的TaSPP同源基因,分别命名为TaSPP-5A、TaSPP-5B和TaSPP-5D。并利用生物信息学对小麦TaSPP的理化性质、基因结构、顺式作用元件、系统进化树和蛋白保守结构域等进行分析,通过qRT-PCR分析基因TaSPP的表达模式。结果表明,TaSPP-5A、TaSPP-5B、TaSPP-5D都包含8个外显子和7个内含子,TaSPP-5A和TaSPP-5D编码422个氨基酸,TaSPP-5B编码413个氨基酸。系统进化分析显示,小麦TaSPP基因与小麦的近缘物种在进化上处于同一分支,相似度较高。qRT-PCR表达分析结果显示,TaSPP基因在根、茎秆、旗叶、叶鞘、颖花、种子中均表达,其中在旗叶和茎秆中表达量较高;ABA、PEG-6000、NaCl和IAA胁迫均能诱导TaSPP基因的表达,表明小麦TaSPP基因可能在逆境胁迫过程中发挥重要作用。     

西南地区1902—2018年干旱时空演变特征分析

鉴于西南地区干旱的危害程度及其严峻形势,定量刻画干旱时空特征、揭示干旱发展规律,已成为抗旱防灾、保障农业健康发展的迫切要求。基于1902—2018年标准化降水蒸散指数(SPEI)数据,统计了西南地区不同等级干旱发生频率及干旱强度,并采用Sen趋势分析、Mann-Kendall检验法和经验正交函数(EOF)分析方法研究了西南地区干旱的时空演变特征,以期为西南地区干旱变化及生态维护提供科学依据。结果表明:(1)1902—2018年西南地区SPEI12整体呈下降趋势,下降速率为0.025/10 a,其中1954—1974年呈干旱—湿润的频繁交替,发生多次不显著突变;(2)西南地区干旱强度均呈增强趋势,其中中旱和重旱强度增强趋势显著;(3)西南地区干旱发生频率存在空间分布差异,其中轻旱发生频率最高,极端干旱最低;(4)西南地区干旱变化趋势以不显著下降为主,占研究区面积的68.22%,表明西南地区百年来呈干旱化趋势;(5)干旱时空模态分析中,3种模态分别反映了研究区干旱全区相同、南北相反、东西相反的分布特征。综上所述,揭示了西南地区干旱的时空变化基本特征。     

几种藜科盐生植物吸盐能力及生态学意义

  【目的】  聚盐能力是评价盐生植物对盐碱地生物改良能力的一个重要参考指标。针对不同的盐碱地类型,有目的地选择生物量大且聚盐能力强的盐生植物,是实现盐碱地快速改良的关键。比较不同盐生植物的盐离子吸收类型及能力,可为盐碱地生物改良选择适宜的植物材料提供参考。  【方法】  试验选取7种藜科盐生植物进行人工种植试验,包括野榆钱菠菜(Atriplex aucheri)、高碱蓬(Suaeda altissima)、盐地碱蓬(Suaeda salsa)、盐角草(Salicornia europaea)、红叶藜(Chenopodium rubrum)、驼绒藜(Ceratoides latens)和四翅滨藜(Atriplex canescens)。试验地土壤以粉粘粒为主,根层土壤(0—40 cm)平均含盐量为45.57 g/kg。在生育末期采样测定植物地上部生物量和Na+、K+、Ca2+、Mg2+、Cl–、SO₄2–浓度。  【结果】  7种藜科植物地上部生物量为野榆钱菠菜(35077 kg/hm2)>盐地碱蓬(19507 kg/hm2)>高碱蓬(16160 kg/hm2)>驼绒藜(12421 kg/hm2)>四翅滨藜(10798 kg/hm2)>红叶藜(10134 kg/hm2)>盐角草(9576 kg/hm2)。高碱蓬、野榆钱菠菜、盐地碱蓬、盐角草和红叶藜5种植物组织内Na+、Cl–和SO₄2–浓度显著高于其他离子(P<0.05),而驼绒藜和四翅滨藜体内K+、Cl–和Na+浓度较高。7种藜科植物地上部Na+、Cl–和SO₄2– 3种盐离子累积总量为野榆钱菠菜(3835 kg/hm2)>盐地碱蓬(3145 kg/hm2)>盐角草(2749 kg/hm2)>高碱蓬(2253 kg/hm2)>红叶藜(615 kg/hm2)>四翅滨藜(367 kg/hm2)>驼绒藜(220 kg/hm2)。  【结论】  盐生植物可在重度盐碱地上存活并产生一定的生物量,野榆钱菠菜、盐地碱蓬、盐角草和高碱蓬均表现出较强的吸盐能力,但对不同离子的吸收累积能力不同。盐地碱蓬地上部SO₄2–吸收量显著高于其他几种植物,适宜于硫酸盐或氯化物–硫酸盐盐渍土的改良;盐角草对Cl–表现出极强的吸收能力,适宜氯化物盐渍土的改良。     

农用微生物菌剂修复退化天然草地技术规程

为农用微生物菌剂在退化天然草地的使用提供标准化的技术指导,从根本上促进草地生态系统的可持续发展,根据前期使用微生物菌剂修复退化天然草地的经验,从适用范围、规范性引用文件、术语和定义、基本原则、修复方法和注意事项等方面规范应用农用微生物菌剂修复退化天然草地的关键技术。     

预测水泥砒砂岩强度的Markov灰色残差模型

为了研究Markov-灰色残差GM(1,1)模型预测水泥固化砒砂岩抗压强度的精准度和适用性,先对抗压强度数据进行了一系列的处理,建立灰色GM(1,1)模型和灰色残差GM(1,1)模型,然后基于马尔克夫过程构建Markov-灰色残差GM(1,1)模型,并以此模型来估算水泥固化砒砂岩的抗压强度.结果表明,灰色残差GM(1,1)模型的检验精度得到了很大的提升且各项检验指标基本上都达到了1级,明显优于灰色GM(1,1)模型.马尔克夫过程便于确定残差修正值的正、负号,采用Markov-灰色残差GM(1,1)模型对不同水泥掺量下90 d龄期的水泥固化砒砂岩的抗压强度进行了预测,相对误差由原来的1.77%~4.01%降低至0.60%~2.36%,平均相对误差由2.63%减小至1.25%,模型的预测精度明显提高.该研究可以为水泥固化砒砂岩以及其他水泥基工程材料抗压强度的预测提供一种简易而可靠的新方法.     

水淹胁迫下的水竹根系生理响应与适应特征

水竹(PPhyllostachys heteroclada Oliv.)是优良的笋材两用竹种,对其研究多围绕其丰产培育技术开展,关于水竹对水淹胁迫的适应特征与响应机制尚不清楚.为探究水淹胁迫下水竹的根系泌H+特征等生理响应及适应特征,通过人工模拟胁迫梯度,采用非损伤微测技术(NMT),测定水竹根系在全淹及半淹条件下的H+流速、抗氧化酶活性、内源激素含量以及非结构性碳水化物含量等变化规律.结果表明:水竹遭受水淹胁迫后根系所处环境的酸碱水平发生改变,根系泌H+现象明显,随胁迫时间延长,通过自身调节适应胁迫逐渐使得H+外排现象回落.水竹根系超氧化物歧化梅(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性整体随胁迫程度增强而上升.另外,根系的淀粉和可溶性糖含量随水淹胁迫时间延长逐渐下降,水淹胁迫短时间内影响了水竹体内非结构性碳水化合物的含量,但含量仍在正常范围之内.综上,水竹遭受水淹胁迫后根系所处环境的酸碱水平发生改变,短时间内影响了水竹体内碳水化合物的含量,显著提高了根系抗氧化能力以清除活性氧(ROS);通过内源激素的协同作用,抑制自身生长以适应淹水环境.     

Winter wheat yield estimation based on assimilated Sentinel-2 images with the CERES-Wheat model

Assimilating Sentinel-2 images with the CERES-Wheat model can improve the precision of winter wheat yield estimates at a regional scale. To verify this method, we applied the ensemble Kalman filter(EnKF) to assimilate the leaf area index(LAI) derived from Sentinel-2 data and simulated by the CERES-Wheat model. From this, we obtained the assimilated daily LAI during the growth stage of winter wheat across three counties located in the southeast of the Loess Plateau in China: Xiangfen, Xinjiang, and Wenxi. We assigned LAI weights at different growth stages by comparing the improved analytic hierarchy method, the entropy method, and the normalized combination weighting method, and constructed a yield estimation model with the measurements to accurately estimate the yield of winter wheat. We found that the changes of assimilated LAI during the growth stage of winter wheat strongly agreed with the simulated LAI. With the correction of the derived LAI from the Sentinel-2 images, the LAI from the green-up stage to the heading–filling stage was enhanced, while the LAI decrease from the milking stage was slowed down, which was more in line with the actual changes of LAI for winter wheat. We also compared the simulated and derived LAI and found the assimilated LAI had reduced the root mean square error(RMSE) by 0.43 and 0.29 m2 m–2, respectively, based on the measured LAI. The assimilation improved the estimation accuracy of the LAI time series. The highest determination coefficient(R2) was 0.8627 and the lowest RMSE was 472.92 kg ha–1 in the regression of the yields estimated by the normalized weighted assimilated LAI method and measurements. The relative error of the estimated yield of winter wheat in the study counties was less than 1%, suggesting that Sentinel-2 data with high spatial-temporal resolution can be assimilated with the CERES-Wheat model to obtain more accurate regional yield estimates.