Deep Root Water Uptake Ability and Water Use Efficiency of Pearl Millet in Comparison to Other Millet Species

Abstract

Pearl millet is better adapted to hot and semi-arid conditions than most other major cereals. The objective of this study was to compare the deep water uptake ability and water use efficiency (WUE) of pearl millet among millet species. First, the WUE of six millet species was evaluated in pots under waterlogging, well-watered (control), and drought conditions. Secondly, the water uptake from deep soil layers by pearl millet and barnyard millet, which showed the highest drought and waterlogging tolerance, respectively, was compared in long tubes which consisted of three parts (two loose soil layers separated by a hardpan and a Vaseline layer). Soil moisture was adjusted to well-watered and drought conditions in the upper (topsoil) layer, while the lower (deep) layer was always kept wet. WUE was significantly reduced in all millet species by waterlogging but not by drought. The ratio of WUE to the control condition indicated that pearl millet had the highest and lowest resistances to drought and waterlogging conditions, respectively, while barnyard millet was the most stable under both conditions. The deuterium concentration in xylem sap water, relative water uptake from deep soil layers, and water uptake efficiency of deep roots were significantly increased in barnyard millet but not in pearl millet by drought in topsoil layers. In conclusion, the drought resistance of pearl millet is explained by higher WUE but not by increased water uptake efficiency in deep soil layers as compared to barnyard millet, another drought-resistant millet species.     

基于灰色灾变理论的开封旱涝趋势分析

根据开封市气象局提供的气象数据,借助灰色灾变理论建立干旱和雨涝的GM(1,1)预测模型,分别对2001年的干旱和2003的雨涝进行预测结果验证,吻合性良好。并对2009~2020年的旱涝情况做出预测。预测结果显示,20102、015、2020年是未来的3个干旱年,20112、0182、025年是未来的3个雨涝年。研究结果可对开封地区抗旱防涝,促进农业生产发展提供科学指导。     

基于决策树和随机森林模型的湖北油菜产量限制因子分析

利用1961-2014年湖北省主产县油菜产量统计资料及同期气象观测资料,采用决策树和随机森林模型,对影响油菜产量的气候因子进行分析。结果表明：温度、日照时数及干旱、湿渍害对油菜产量均有不同程度的影响,且因生育期不同而存在差异。油菜开花期以前对低温敏感,开花期以后对高温敏感;苗期和蕾薹期对干旱较敏感,开花期和角果期对湿渍害更敏感;日照时数对油菜产量的影响受水分状况的制约,在干旱状况下日照偏多不利于产量形成,偏湿状况下则表现为日照越多越有利于产量形成。在各限制因子中,以湿渍害发生频率对油菜产量的影响最高,其次是干旱和冻害。湿渍害对产量的影响以高湿寡照的次生灾害影响较土壤偏湿的直接影响更大     

花后渍水、高温及其复合胁迫对小麦籽粒蛋白质含量和面粉白度的影响

2011-2012和2012-2013年小麦生长季, 利用盆栽模拟试验研究了花后土壤渍水、高温及其复合胁迫对小麦籽粒蛋白质组分含量和面粉白度的影响。结果表明, 花后渍水、高温及其复合胁迫均导致小麦粒重的下降, 2011-2012年度使郑麦366千粒重分别下降10%、23%和16%, 而郑麦004 分别下降7%、27%和32%, 处理间差异显著; 2012-2013年度粒重变化与上一年度趋势一致, 但降幅较小。渍水使两品种蛋白质及其组分含量降低, 高温使蛋白质及其组分含量增加。渍水和高温复合胁迫对两品种的影响不同, 郑麦004籽粒总蛋白质及其组分含量两年度均显著增加, 而郑麦366在2011–2012年度无显著影响, 在2012–2013年度显著下降。在3种胁迫条件下, 郑麦366面粉亮度分别下降0.9%、1.2%和1.9%, 郑麦004面粉亮度分别下降0.2%、2.1%和1.7%; 郑麦366红度分别增加15%、33%和43%, 郑麦004红度分别增加0.3%、77.0%和42.0%; 郑麦366灰度分别增加4%、2%和11%, 郑麦004灰度分别增加4%、7%和8%。相关分析表明, 籽粒蛋白质和麦谷蛋白质含量与面粉亮度呈极显著负相关, 而与红度和灰度呈显著正相关。     

Assessment of surface and sub-surface waterlogged areas in irrigation command areas of Bihar state using remote sensing and GIS

Satellite remote sensing coupled with Geographical Information Systems (GIS) offers an excellent alternative to conventional mapping techniques in monitoring and mapping of surface and sub-surface waterlogged areas. In the present study, pre-monsoon and post-monsoon surface waterlogged areas were delineated in all the 132 irrigation command areas of the Bihar State, India using Indian Remote Sensing (IRS-1D) Linear Imaging Self Scanning Sensor (LISS-III) data acquired during the period 2002–2003. Normalized Difference Water Index (NDWI) was used primarily to delineate surface waterlogged areas. Perennial waterlogged and seasonal waterlogged areas were identified for the study area by integrating the waterlogged areas derived for both the pre- and post-monsoon seasons under GIS environment. Results show that the total surface waterlogged area in Bihar is 628 × 10³ ha, which is 10.57% of command area (5939 × 10³ ha) and spread over 132 command areas. Perennial surface inundation covers 2.95% of the waterlogged area in all the command areas. Maximum waterlogged area is observed in Gandak command (212 × 10³ ha) followed by Eastern Kosi irrigation scheme (116 × 10³ ha) and Sone modernization scheme (82 × 10³ ha), respectively. Further, waterlogged areas induced by rise in groundwater level were also assessed spatially under GIS environment using the ground water level data pertaining to pre- and post-monsoon seasons of the year 2002–2003 which were spread all over the study area. The analysis of pre- and post-monsoon groundwater levels indicates that the area under non-critical category during pre-monsoon period was reduced from 4287 × 10³ ha (72.72% of command) to 1391 × 10³ ha (23.42%) in the post-monsoon. Area under most critical category during post-monsoon period increased from 0.083 × 10³ ha of command area in pre-monsoon period to 50 × 10³ ha. The study demonstrates utility of integration of remote sensing and GIS techniques for assessment of waterlogged areas particularly in regions where waterlogging conditions occur both due to excessive irrigation and accumulation of rain and floodwaters.     

淹水胁迫对不同紫花苜蓿品种产量和品质的影响

为确定淹水胁迫下适应性相对较强的苜蓿(Medicago sativa)品种,以‘金皇后’(B1)、‘阿尔金刚’(B2)、‘维多利亚’(B3)、‘巨能551’(B4)和‘巨能耐湿’(B5)为材料,研究了淹水处理对不同苜蓿品种群体质量和品质的影响。结果表明,随着淹水时间增加,不同苜蓿品种草产量之间差异显著,与0d相比1d淹水处理下B3,B4,B5的产量增加,随水淹胁迫时间的增加产量逐渐下降,而B1,B2则随淹水时间延长持续降低,5d时各品种草产量表现为B5B1B4B3B2;短期淹水对B1,B3,B5株高有促进作用,之后随时间延长逐渐降低,淹水5d时明显高于B2,B4。淹水5d时,B1,B4,B5的叶片数显著高于B2,B3,而B5的生长速率较0d仅降低15.38%,生长速率显著高于其他品种,其节间数、分枝数、根长和根重也均显著高于其他各品种;同时淹水5d时,B5光合能力显著强于其他品种,表现为B5B1B4B2B3;而品质上,B1,B4,B5在水淹胁迫后牧草品质均显著优于B2和B3。综上所述,‘巨能耐湿’(B5)在淹水胁迫下抗逆和恢复能力表现较好,群体质量相对较高,对产量品质影响较小,适宜在我国淮河以南多雨地区推广种植。     

氮肥后移促进受渍夏玉米根系形态恢复和提高花后光合性能

江淮地区受梅雨影响,玉米苗期易发生渍害,如何通过合理运筹氮肥达到减灾效果值得研究。以夏玉米品种‘隆平206’为试验材料,研究不同氮肥运筹方式[氮肥全部基施(N1)、基肥70%+拔节肥30%(N2)、基肥50%+拔节肥50%(N3)和基肥30%+拔节肥50%+大喇叭口肥20%(N4)]对苗期受渍夏玉米根系形态和花后光合性能恢复的影响,以期为苗期受渍夏玉米合理施肥提供理论依据。结果表明,苗期渍水7 d抑制根系生长,根重、根长度、根表面积和根直径均显著降低,渍水对根系形态指标抑制效应表现为:根长度根表面积根直径。氮肥后移对渍水后根系生长有显著的补偿效应,氮肥后移量增加,根重、根长度和根表面积显著增加。渍水胁迫解除后18 d,N1-N4处理根长度较渍水前提高1.9~5.1倍,根表面积提高6.3~10.3倍,根直径提高0.7~1.0倍,氮肥后移对根系形态指标补偿生长效应强弱表现为:根表面积根长度根直径。渍水使群体叶面积系数降低9.3%~22.5%,氮肥后移可提高群体叶面积系数,较全部基施处理提高3.2%~20.7%。苗期渍水7 d显著降低灌浆期间穗位叶片的光合能力,净光合速率下降,灌浆中期和末期净光合速率分别下降16.1%和28.9%,灌浆后期光合能力下降幅度高于对照,非气孔限制是导致渍水胁迫下净光合速率下降的主要原因。渍水胁迫下,氮肥后移处理改善了穗位叶光合性能,光合能力优于氮肥前移处理。在苗期易导致渍害的地区适当减少基肥比例,后移氮素至拔节期和大喇叭口期,能够对受渍夏玉米起到较好的补偿生长效应。     

淹水胁迫对香根草生理生化特性的影响

采用完全随机化试验设计研究了不同淹水胁迫对香根草生理生化特性的影响。结果表明:全淹(Y3)、半淹(Y2)条件下POD活性随时间延长均升高,根淹(Y1)条件下先升高后降低;全淹、半淹条件下MDA含量随时间延长均减少,根淹条件下增加;全淹条件下相对电导率随时间延长变化不明显,半淹、根淹条件下降低;全淹条件下叶绿素含量随时间延长先升高后降低,半淹下升高,根淹下先下降后升高。淹水50d,各处理POD活性、相对电导率、叶绿素含量均高于对照(CK);全淹、半淹的MDA含量低于对照,根淹高于对照。     

湿涝胁迫对不同种质花生生长和农艺性状的影响

研究了花生营养生长末期至开花期根部淹没处理对18个不同耐涝性品种的影响.结果表明, 湿涝使多数花生品种株高降低, 单株分枝数、总果数与饱果数减少, 而果、仁生长得以促进且饱满度提高.经过湿涝处理后, 基于性状变化的品种聚类分析结果与基于产量变化的品种耐涝性分类有较高统一性(18个品种可归类为6个性状变化类型), 又有一定差异性, 即多数湿涝敏感品种的果、仁数量或重量性状不同步变化, 而经过湿涝生态压力选择选育的绝大多数耐性品种表现为株型变小, 果、仁数量或重量性状同步增长, 且饱果数率、饱果重率提高.说明耐湿涝生态育种是有成效的.在需水较多的生育期(营养生长末期至开花期), 只要有流水通过且花生植株顶部不被淹没, 湿涝的影响是有限的, 对多数耐涝品种甚至可促进果仁发育.因此, 对花生受洪涝灾害影响的评估, 应因湿涝程度、发育时期、品种耐性而异.     

两种核桃砧木的生长发育规律及耐涝性分析

对铁核桃、黑核桃生长发育规律及耐涝性进行了分析,结果表明:(1)与铁核桃相比,黑核桃萌发期偏迟,但新稍封顶早、落叶早。(2)铁核桃在整个观测期生长迅速,5—6月生长速度最快,而黑核桃主要生长期集中在5—7月,7月中旬以后生长量偏小;(3)极端高温天气、水分不足是黑核桃在引种区生长较差的主要因素;(4)黑核桃耐涝性强于铁核桃。