不同水(陆)稻品种(系)干旱胁迫效应分析评价

为了扩大水稻抗旱资源的应用,提高水稻抗旱育种效率,对来自17个不同国家105份水(陆)稻品种(系)进行干旱胁迫效应评价。采用了同异分析法,在干旱胁迫下,株高、单株有效穗、穗长、每穗实粒数、每穗总粒数、结实率、千粒重、单株谷重8项农艺及经济性状,进行了综合评价分析。结果表明:105份水(陆)稻品种(系),分析评语"差"的有60个品种,占57.1%;"一般"的评语共有22个品种,占21%;"较好"和"好"的评语各有10个品种,占9.5%;"优良"的只有4个品种,占3.8%,分别为IR77298-14-1-2-13、IR77298-5-6-18、CACHO PRETO、IR77298-5-6-11,均为籼稻品种。由此得出,籼稻品种抗旱性明显高于粳稻品种,抗旱同异评语的级别与每穗实粒数、结实率、单株谷重3个性状密切相关。     

基于村民参与式的乡村人居环境评价研究

乡村人居环境改善是城乡统筹发展的重要内容,也是美丽乡村建设的关键所在。笔者着眼于“以人为本”的视角,以重庆市铜梁区南城街道鱼溅村为例,通过村民参与式与数学模型定量的研究方法,研究乡村人居环境村民的满意度和优化方向。研究结果显示：鱼溅村人居环境的整体满意度水平一般,人居软环境系统的社会环境与经济环境满意度为一般和不满意,硬环境系统的设施环境和生态环境对整体满意度贡献率较高,结论表明鱼溅村亟需加强对人居软环境系统的优化;同时,研究还显示鱼溅村人居环境满意度的空间分布差异较大,这说明人居环境的优化需要合理布局、整体筹划。笔者最后提出了优化的对策,对山地丘陵地区的乡村人居环境建设具有普遍借鉴意义。     

长江中下游中籼杂交稻区试品种产量成因性状分析

基于2008—2012年南方稻区国家水稻品种区试数据,运用相关分析、通径分析和主成分分析方法,分析了长江中下游地区中籼杂交水稻5年220个参试品种的农艺性状与产量形成的关系,结果表明,有效穗数、每穗总粒数与结实率对产量显著正相关,其中对产量贡献最大的是结实率,千粒重与产量极显著负相关。在长江中下游杂交稻育种过程中,应以每穗总粒数和结实率为中心兼顾有效穗数和千粒重,协调优化产量构成因素的关系,建立良好的群体结构,发挥中籼品种产量的潜力。综合各种分析及结合长江中下游杂交中籼的9t/hm²以上的的高产组合,得出其产量结构是：有效穗数达到255万/hm²左右,株高在122cm以下,每穗总粒数达到180~200粒,结实率80%以上,千粒重27g左右。     

完全信息静态博弈下农业保险分析——以甘肃省为例

为促进甘肃省农业保险政策的完善及提高农户对农业保险的有效需求,进而促进甘肃省农业保险的可持续发展,本研究针对农业保险市场上政府、保险公司和农户三大利益主体之间的相互影响关系,采用完全信息静态博弈理论对各个利益主体的收益进行博弈分析,同时结合甘肃省实地调研数据,选取逻辑回归分析方法提取影响农户参与农业保险的主要因素。分析得出：在保险公司和农户的博弈中,保险公司在农户有投保意愿时应当做出的积极回应为不经营策略,如果选择经营,则会损失更多(-M-P+C<0),其中,C为农户的投保金额,M为出险后农户获得的保险金,P为保险公司的经营成本;农户在保险公司做出经营策略的时候,应当积极投保,这样才能获得收益,如果保险公司选择不经营,农户无论做出什么选择,都会损失预防灾情的资金N,并且如果农户选择投保还会损失更多;在政府与保险公司的博弈中,可以看出,政府的最佳收益为0,说明政府不支持保险公司进行农业保险业务是最佳策略;而对保险公司来说,只有在政府支持的情况下,才能获得最佳收益（-M-P C Q),其中,Q表示政府对保险公司的支持成本,这说明,只有在政府支持的情况下,保险公司经营农业保险的积极性才能提高。逻辑回归分析表明文化程度、务农人数、耕地面积、农业收入占家庭收入比重、了解农业保险程度对农户农业保险购买行为具有显著的影响。     

转MvNHX1和MvP5CS基因棉花耐盐抗旱性比较与育种价值分析

通过对花粉管通道法获得的T7转MvNHX1基因的10个棉花株系和转MvP5CS基因的3个棉花株系与对照非转基因棉花D5在温室内盐和干旱胁迫下的发芽率、生理生化指标以及田间花期干旱胁迫下农艺性状和纤维品质进行分析发现:温室内盐和干旱胁迫后,转基因棉花叶片叶绿素含量、脯氨酸含量均高于对照,而丙二醛含量低于对照;田间花期干旱胁迫下,2种转基因植株果枝数、有效果枝数、铃数、有效铃数、铃重、子棉、皮棉、衣分、子指和衣指均高于对照,说明转MvNHX1基因和转MvP5CS基因植株在干旱逆境下的产量高于非转基因;经花期干旱胁迫后,2种转基因棉花的纤维断裂伸长率、短纤维率、马克隆值和纺纱一致性指数优于非转基因棉花D5。综合分析表明:2种转基因棉花的耐盐抗旱性均有提高,其中转MvNHX1基因棉花的耐盐性优于转MvP5CS基因棉花植株,而转MvP5CS基因棉花植株的抗旱性优于转MvNHX1基因棉花植株。     

The genetic relationship between popping expansion volume and two yield components in popcorn using unconditional and conditional QTL analysis

Popping expansion volume (PEV) is the most important quality trait in popcorn, while its germplasm is inferior to normal dent/flint corn in yield. In this study, 259 F_2:3 families, developed from the cross between a dent corn inbred Dan232 and a popcorn inbred N04, were evaluated for their PEV, grain weight per plant (GWP) and 100-grain weight (100 GW) in two environments. The genetic relationship between PEV and GWP, and 100 GW on individual gene loci were evaluated using unconditional and conditional QTL mapping methods. In total, five, one and three unconditional QTL were identified for PEV, GWP, and 100 GW, respectively. The positive alleles of all QTL for PEV were from N04, while positive alleles of all QTL for GWP and 100 GW were from Dan232. In conditional mapping, one and two QTL failed to be detected, and all four additional QTL were detected. Nevertheless, three QTL were identified, which controlled PEV independently from GWP/100 GW. They seemed to be potential candidates in popcorn breeding to increase PEV without decreasing GWP/100 GW. The results suggested that for significantly correlated traits, the conditional QTL mapping method could be used to dissect the genetic interrelationship between traits at the level of individual QTL, as well as reveal additional QTL that were undetectable by unconditional mapping.     

Predicting spring barley yield from variety-specific yield potential, disease resistance and straw length, and from environment-specific disease loads and weed pressure

For low-input crop production, well-characterised varieties increase the possibilities of managing diseases and weeds. This analysis aims at developing a framework for analyzing grain yield using external varietal information about disease resistance, weed competitiveness and yield potential and quantifying the impact of susceptibility grouping and straw length scores (as a measure for weed competitiveness) for predicting spring barley grain yield under variable biotic stress levels. The study comprised 52 spring barley varieties and 17 environments, i.e., combinations of location, growing system and year. Individual varieties and their interactions with environments were analysed by factorial regression of grain yield on external variety information combined with observed environmental disease loads and weed pressure. The external information was based on the official Danish VCU testing. The most parsimonious models explained about 50% of the yield variation among varieties including genotype-environment interactions. Disease resistance characteristics of varieties, weighted with disease loads of powdery mildew, leaf rust and net blotch, respectively, had a highly significant influence on grain yield. The extend to which increased susceptibility resulted in increased yield losses in environments with high disease loads of the respective diseases was predicted. The effect of externally determined straw length scores, weighted with weed pressure, was weaker although significant for weeds with creeping growth habit. Higher grain yield was thus predicted for taller plants under weed pressure. The results are discussed in relation to the model framework, impact of the considered traits and use of information from conventional variety testing in organic cropping systems.     

价格、价值与稳定的博弈——农村宅基地抵押的多视角分析

旨在分析不同得益主体对宅基地利用效益追求的侧重点,以三者统一为出发点,思考如何在宅基地产权缺失的背景下,处理国家、金融机构及农户的利益分配问题。利用SPSS 软件,选择二元Logistic模型,采用Wald法,分为3 个层面对不同效益进行量化,并从中选出显著性较高的不同指标。通过对其结果的分析,可以得出以下结论：首先,农户行为具有“理性经济人”的一般特征,但盲目性较大,难以维持稳定发展的趋势;其次,金融机构无法在相关法律法规框架内实现对宅基地抵押的实际操作,同时难以对宅基地进行客观的价值评估;第三,政府需要健全宅基地入市相关法律法规,加大基础设施建设,提升农村土地资产价值,提高农户抵御风险和偿还贷款的能力;第四,破解宅基地抵押入市的切入点应在于法的建立及权的确定。     

Calibration of Nonlinear Dynamical Analysis for RC Frame-wall Structure with Slender Coupling Beams Considering Stiffness Reduction

Two 16-storey frame-wall structures with slender coupling beams in regions of Intensity 8(0.2 g),with and without considering the stiffness reduction of the coupling beams,were designed.Nonlinear dynamic response analyses of two typical frame-wall structures subjected to several ground motions were carried out.The analyses were based on the quasi-tridimensional program for nonlinear dynamic response analysis TS-EPA.The analyses led to the following conclusions: Under rare earthquake actions,the coupling beams in framewall structures yield first.This shows that the coupling beam in frame-wall structures is the member at the forefront of earthquake resistance.Comparison of the analytic results of two couples with and without considering the stiffness reduction of the coupling beam found that,in view of the dynamic response to and the requirement for ductility under rare earthquake motions,reducing stiffness causes a minor unfavorable influence on the dynamic response of frame-wall structures.     

Site selection for a measuring and controlling device of initial phase based on maximum elevation angle

We introduced a site selection method based on the modified maximum elevation angle intended for mountains possibly affecting the measurement and control of the initial phase in a launching port located in mountainous areas. To use the former analysis results, the method, along the helices whose center is the launcher's project point, analyze each point's visibility on the helices. The visible area can be obtained by comparing the visibility at each moment in the initial phase. Finally, there can be three points in the above visible area with distances longer than required.