水稻多基因型种群品种不同生态稻区的适应性研究

旨在探究水稻多基因型种群品种在不同生态稻区的适应性和稳定性,为多基因型种群品种的推广提供依据。选用参试品种‘尤群6号’、‘南八糯’和对照品种‘红优7号’开展田间试验,通过抗病性、农艺性状等指标进行综合评价。结果表明：参试品种‘尤群6号’(0.40~0.95 kg/m2)和‘南八糯’(0.81~1.04 kg/m2)在4个稻区产量显著高于对照品种（尤群6号在文山地区表现除外）;田间发病总体较轻,个别品种在局部试验点表现有差异,‘尤群6号’在文山稻瘟病发生 (DI=48.66)和粳稻区楚雄稻曲病发生相对较重,仍需继续种植综合观察;品种生育期随试验点海拔的升高而缩短,株高随月平均气温升高而增高,品种内株高变异系数介于1.97~6.13之间。研究表明参试品种在籼粳混栽区红河表现最佳,籼稻区德宏表现较好,在文山、楚雄田间表现有待继续评价;总体上,表现出较好适应性和稳定性。     

黑龙江垦区耕地占补平衡存在的问题及对策研究

为了健全非农建设项目占用耕地的补偿机制,保障国家粮食战略后备基地储粮充足。本研究运用空间分析、实证研究等方法,对黑龙江垦区各管理局2000-2014年耕地增减变动情况进行分析。发现其在耕地占补平衡政策实施过程中存在制度缺失、“占优补劣”、农民不合理利用土地以及自然条件的局限等问题。通过借鉴建三江管理局耕地占补平衡的创新经验,完善垦区专门性制度规范,不单纯以数量作为耕地占补平衡衡量标准、借助现代技术手段实现对表土的充分利用,形成体系化改革。助力垦区乃至全国其他地区全面实现耕地占补平衡,从而实现耕地的可持续发展,保障国家粮食安全。     

气候因子和地表覆盖对沿海滩涂土壤盐分动态的影响

为探明气候因子对沿海滩涂表层土壤盐分季节性变化规律的影响,并探讨植被和秸秆覆盖对滩涂土壤脱盐效果及控盐的作用。2014年5月—2015年5月,在江苏沿海滩涂盐碱地(中重度盐分),设置4种处理进行田间试验,分别为对照(裸地,CK)、秸秆覆盖(覆盖量为15 t·hm-2,SM)、植被覆盖(PC)和植被+秸秆覆盖(覆盖量为7.5 t·hm-2,PC+1/2SM),监测了气候因子和表层土壤盐分的季节性动态变化。结果表明:1)在沿海滩涂裸地中,土壤盐分具有一定程度的季节性规律,表现为在10—12月具有明显的积盐效果,且在10月EC1︰5达到最大值为3.90 d S·m-1。2)相关分析表明:采样前7 d降雨累积量与土壤盐分变化有着极密切负相关关系;气候因子的多因子及互作逐步分析表明:降雨量增加可以促进土壤脱盐作用,大气温度升高可加剧土壤盐分表聚,降雨量和大气温度的互作效应增加会对土壤盐分累积产生正效应。3)地表覆盖(包括PC和SM)显著地改变了气候因子对土壤盐分动态变化的影响,累积降雨量和大气平均温度与土壤盐分无显著相关性,且大量秸秆覆盖对滩涂表层土壤脱盐具有更明显的效果。因此,在沿海气候向暖湿方向发展的趋势下,综合考虑脱盐及控盐作用,选择适量秸秆覆盖(如覆盖量15 t·hm-2)或适量秸秆覆盖结合植被种植覆盖,同时充分利用沿海地区降雨量集中的特点,可能是未来滩涂盐碱盐渍土快速脱盐和土壤改良的重要措施。     

亚洲中部干旱区降水异常的大气环流特征

亚洲中部干旱区(中亚五国和新疆)是地中海气候与东亚季风气候的过渡带,区域天气气候与欧洲和东亚季风区迥异,具有世界独特的干旱区生态气候模式,即山地森林草原—盆地平原绿洲寓于荒漠,并与荒漠共存的生态气候地理格局。天气气候受高、中、低纬环流的共同影响,区域内部差异很大,形成多背景、多因子、多尺度影响下的极具代表性的气象灾害孕育和成灾环境。亚洲中部干旱区光热资源丰富、蒸发量大、气温变化剧烈,而降水稀少,且分布极不均匀,天山山脉的中西段是降水高值区,近百年来整体表现为增暖、增湿趋势。高、中、低纬系统和中亚低值系统的活跃,共同造就了中亚东部(新疆)降水年代际和年际异常增多。西亚西风急流是联系高、中、低纬环流系统相互作用的纽带。目前,该区域气象综合观测网建设不能满足应对气候变化的需求,同时对区域特有的环流系统、灾害性天气气候发生规律和形成机理、高分辨率区域数值模式、地—气相互作用对区域天气气候的影响、气候变化预估等方面的研究也较薄弱,开展上述研究对"丝绸之路经济带"可持续发展具有重要科学意义和战略价值。     

Local and scientific knowledge to assess plot quality in Central Spain

Farmers’ land management is a key factor for sustainable agriculture, yet the traditional knowledge which constitutes its base is seldom incorporated in the land and soil academic literature. The need for a hybrid approach that combines local (farmers’) and scientific knowledge is formally recognized. Plot quality criteria are a component of both sources of knowledge, playing an important role in shaping land management practices. Yet there are few case studies comparing the criteria used by farmers and soil scientists when assessing plot quality, particularly in developed countries. We compare the plot quality assessment done by a sample of 31 farmers in a semiarid area of Spain with an edaphic quality index (EQI) obtained through laboratory analyses of soil samples from 61 farm plots. There is a coincidence between farmer and laboratory assessments in 70% of cases. Plots identified by farmers as being of good quality have a significantly higher EQI than those identified as bad quality. The two key differentiating parameters were clay content (average 21% in good versus 18% in bad quality plots) and soil organic carbon content (1.6 and 1.3%, respectively), both closely related to soil water retention ability. A holistic land vision, a higher level of education and large differences in EQI between good and bad plots as assessed by farmers have a positive influence in the degree of coincidence between farmers’ and laboratory assessments.     

Ground-active arthropod response to distance from the Mediterranean seashore in coastal sand areas of western Israel

Information on the effects of distance from the seashore on soil biotic communities is limited and restricted to soil arthropods and microarthropods. The aim of this study, conducted in a sand-dune area, was to distinguish the changes of a ground-active arthropod community along a 4-km-transect from the seashore going inland. Pitfall traps were set up in open spaces at four locations (L1, through L2, L3, and L4 going inland) through the year. The abiotic gradient from the seashore going inland was found to be mostly dependent on seasonality. Group richness was found to be remarkably greater at the L2, L3, and L4 locations compared with the L1 location in winter, and at the L2 and L3 locations compared with the L1 location in spring. The Fisher α index was 0.32?±?0.21, 3.51?±?0.87, 5.04?±?0.70, and 4.86?±?0.54 in winter and 3.29?±?0.55, 13.79?±?1.49, 10.12?±?1.24, and 5.06?±?0.62 in spring at the L1, L2, L3, and L4 locations, respectively. Regarding abundance and group richness, the trophic relationships between predators, phytophages, omnivores, and saprophages were remarkably affected by both location and seasonality. The dominant groups and dominant index distribution of ground-active arthropod communities were found to follow a similar pattern. Soil organic carbon content was found to be the key factor driving the ground-active arthropod community structure along a coastal gradient going inland in winter and spring. We conclude that the distribution, trophic composition, and diversity index are affected by both location and seasonality, while total abundance is consistently affected by location across all three seasons.     

半干旱区玉米行距调整增密对群体冠层结构及产量的影响

为增加玉米种植密度,构建不同的群体冠层结构,以玉米不同行距配置为基础,研究乳熟期玉米群体的光能利用情况,分析不同行距配置对冠层结构及产量、产量构成因素的影响。结果表明,玉米产量与群体消光系数达到显著相关,且为负相关。在吉林省半干旱区玉米宽窄行行距70-30 cm和宽窄行行距80-30 cm配置下玉米群体对光能资源的利用达到最佳,且有效提高玉米群体产量,增产分别达到8.06%和22.82%。     

不同区域对谷子农艺性状的影响

为明确两个谷子品种的高产优势区,并探讨如何通过光温获得目标性状,本研究以山西7个典型地域:山西五台县(A1)、山西定襄县(A2)、山西平定县(A3)、山西省农科院高粱所(山西晋中市,A4)、山西省农科院经济作物所(山西汾阳市,A5)、山西省农科院谷子所(山西长治市,A6)和山西高平市(A7)为试验地点,以农大8号和长农35号为材料,对农艺性状进行研究分析。结果表明,不同地域显著影响谷子生育期、主茎高、留苗密度和穗粒重以及产量。品种差异是造成千粒重与穗长的主要因素。农大8号生育期显著小于长农35。由于谷子的分蘖能力可以随环境而自我调节,使得不同地域谷子穗数差异不显著,也使得不同地域谷子穗数与留苗密度的相关性不明显。本试验中穗重与穗粒重是构成产量的主要因素。农大8号的穗粒重与主茎高对地域反应很敏感且跟纬度呈正相关关系。在产量、千粒重、穗数与穗长方面农大8号在7个地域均表现适应,且综合评价结果明显好于对照品种,而长农35号的穗长在山西五台县表现最好,长农35在主茎高方面综合评价优于农大8号。除主茎高方面外,农大8号的抗逆性高于长农35号。在栽培过程中可以通过对光温的控制与调节来协调各因素以调整谷子农艺性状。     

黄淮南片小麦高分子量谷蛋白亚基组成及其与品质的关系

为了解小麦高分子量谷蛋白亚基(HMW-GS)组成与品质之间的关系,对177份黄淮南片地区小麦品种(系)的HMW-GS组成及其品质进行了检测。结果表明,177份材料在Glu-A1位点上有3种亚基类型(N、1、2*),在Glu-B1位点上有5种亚基类型(7+8、7+9、14+15、17+18、13+16),在Glu-D1位点上有3种亚基类型(2+12、5+10、5+12),1、14+15、5+10亚基的出现频率分别为73.45%、11.86%和48.02%。1、7+8、17+18、5+10亚基对蛋白质含量、湿面筋含量、峰值曲线面积、峰高、SDS沉淀值、8min带高、8min曲线面积、形成时间、稳定时间都具有较大的正向效应。共检测到19种不同的亚基组合类型,其中1/7+8/5+10亚基组合的小麦品种(系)各项品质指标均较优,其次是1/7+8/2+12亚基组合品种(系),N/7+9/2+12和N/14+15/5+10亚基组合类型小麦的品质较差。     

滨海台地典型森林类型土壤可溶性有机碳季节变化

针对海南文昌滨海台地3种森林类型(人促更新次生林、次生林、椰子林)土壤可溶性有机碳含量进行测定。结果表明:次生林、人促更新次生林和椰子林土壤可溶性有机碳含量在0~100 cm剖面随土层加深而下降,且季节动态变化一致,表现为旱季高于雨季。旱季可溶性有机碳分配比例波动在1.2%~3.6%,随着土层深度增加比值不断增大,至40~100 cm土层变为2.6%~3.6%,表现为深层土壤高于表层土壤。土壤可溶性有机碳氮比值在不同森林类型间存在显著差异,且越往土层深处,差异越显著。说明滨海台地土壤可溶性有机碳、氮含量受雨水淋溶强度大,不同森林类型之间土壤可溶性有机碳含量对降雨强度的敏感性存在较大差异。