平邑甜茶后代双胚苗的倍性鉴定及核型分析   总被引：1，自引：0，他引：1  

王颖  周攀  魏鑫  王玉霞  董文轩 《果树学报》2009,26(2)

为了确定平邑甜茶双胚苗的倍性特征和核型特点,采用压片和流式细胞仪观测的方法对平邑甜茶后代中双胚苗进行染色体倍性观察和核型分析。结果表明:4株供试材料均为三倍体,2n=3x=51,染色体为小型,染色体长度比差异不大;核型组成由中部着丝点染色体(m)和亚中部着丝点染色体(sm)组成;株系8-1、8-2、12-1和12-2的核型公式分别为2n=3x=45m+6sm,2n=3x=48m+3sm,2n=3x=27m+24sm,2n=3x=33m+18sm;染色体相对长度和着丝点指数的变异范围分别为1.21%～2.68%和34.19%～42.37%,1.44%～2.63%和35.59%～44.08%,1.36%～3.02%和32.85%～42.18%,1.43%～2.87%和34.23%～44.02%;核型分别属于1B、1A、2B和1B类型,表现为株系之间的核型不完全相同。本研究为丰富无融合生殖型砧木的育种理论,获得新的苹果无融合生殖型砧木提供有益的借鉴。  相似文献   

中国野生葡萄抗黑痘病基因RAPD标记的克隆、序列分析及辅助育种应用   总被引：4，自引：0，他引：4  

张剑侠  王跃进  张艳艳  周邦军 《果树学报》2009,26(4)

对中国野生葡萄抗黑痘病基因RAPD标记OPS03-1300进行了克隆、测序及序列分析,结果表明该标记实际长度是1354bp,因此更名为OPS03-1354,其GenBank登录号为DQ350885。该标记序列与99条来自欧洲葡萄的EST有同源性,其中与1条来自赤霞珠叶片感染葡萄皮尔斯病病原菌后获得的EST同源性为82%,与2条来自赤霞珠果实在不同发育期获得的EST同源性分别为80%和85%。该序列与1条来自中国野生华东葡萄白河-35-1叶片接种霜霉病病原菌后获得的EST同源性为67%。该序列编码葡萄的一种假定蛋白。此外,应用该标记对中国野生葡萄与欧洲葡萄的种间杂交广西-1×京可晶F1代339株、白河-35-1×佳利酿F2代207株进行了辅助选择。  相似文献   

Image processing-based study of soil porosity and its effect on water movement through Andosol intact columns     

B. Prado  C. Duwig  P. Delmas  J. James 《Agricultural Water Management》2009,96(10):1377-1386

The soil pore network and marcoporosity are important factors affecting water and solute transport. The transfer of contaminants to water resources is of particular importance in the Valle de Bravo watershed as it provides 10% of the drinking water for the 20 million inhabitants of Mexico City. This watershed is composed mainly of Andosols with unique mineralogical and physical characteristics. Soil porosity is usually examined on thin sections, using various image analysis techniques. We propose a novel methodology combining image analysis and a displacement experiment to study relationships between soil structure and water tracer transport parameters. H₂¹⁸O displacement experiments were conducted through intact soil columns sampled at three depths from a representative cultivated Andosol profile. The soil structure and pore characteristics were obtained by image analysis on thin sections obtained from each column at the end of the displacement experiment. The total 2D porosity (for pores larger than 50 μm) varied from 80% of the total section area in the topsoil to around 60% in the subsoil. Tubular pores were the most abundant in the soil profile, but ploughing of the topsoil had destroyed sections of these pores and replaced them with packing pores. Water transport in the intact subsoil columns was always in physical non-equilibrium, showing the existence of preferential flow pathways. In the topsoil, one column out of three showed no preferential flow, demonstrating that soil ploughing also homogenised pore connections. Pore connectivity was larger in the ploughed topsoil than in their deeper soil horizon counterparts. Our methodology offers a 2D quantitative characterisation of the macroporous network at 50 μm resolution and the determination of water transport parameters on the same intact soil samples. 3D characterisation of soil porosity using X-ray computed tomography (CT) gives a better picture of pore connection but usually has lower spatial resolution and a larger cost.  相似文献   

FSWM: A hybrid fuzzy-stochastic water-management model for agricultural sustainability under uncertainty     

Y.P. Li  G.H. Huang  G.Q. Wang  Y.F. Huang 《Agricultural Water Management》2009,96(12):1807-1818

A hybrid fuzzy-stochastic water-management (FSWM) model is developed for agricultural sustainability under uncertainty, based on advancement of a multistage fuzzy-stochastic quadratic programming (MFSQP) approach. In MFSQP, uncertainties presented in terms of fuzziness and randomness can be incorporated within a multilayer scenario tree, such that revised decisions are permitted in each time period based on the realized values of the uncertain events. Moreover, fuzzy quadratic terms are used in the objective function to minimize the variation of satisfaction degrees among the constraints; it allows an increased flexibility in controlling the system risk in the optimization process. Results of the case study indicate that useful solutions for the planning of agricultural water management have been obtained. In the FSWM model, a number of policies for agricultural water supply are conducted. The results obtained can help decision makers to identify desired water-allocation schemes for agricultural sustainability under uncertainty, particularly when limited water resources are available for multiple competing users.  相似文献   

Estimating the impacts of water pricing on smallholder irrigators in North West Province, South Africa   总被引：1，自引：0，他引：1  

Stijn Speelman  Jeroen Buysse  Stefano Farolfi  Aymen Frija  Marijke D&#x;Haese  Luc D&#x;Haese 《Agricultural Water Management》2009,96(11):1560-1566

Worldwide growing water scarcity has increased the call for economic instruments to stimulate rational water use in agriculture. Furthermore, cost-recovery is now widely accepted as a cornerstone of sustainable water management. In many developing countries, where agricultural water use is often still subsidised, water pricing policies are developed for allocating water efficiently and achieving sustainability of water systems. However, the impacts of water pricing policies on irrigation water use and on farm production systems is mostly unknown. We introduce an innovative two-stage methodology that allows estimating these effects at farm level. Applying the method to small-scale irrigators in South Africa, we show that water demand is quite responsive even to small changes in water price. In addition, the introduction of a water price significantly decreases farm profit. This appears to be a problem primarily for the poorer farmers.  相似文献   

草方格铺设机器人多体动力学仿真与试   总被引：2，自引：1，他引：1  

刘晋浩  潘海兵  舒庆 《农业机械学报》2009,40(6):153-157

采用Pro/E和ADAMS软件相结合的方法,建立了草方格铺设机器人动力学模型,同时探讨了二者联合建模仿真的一般步骤.模型添加必要的边界条件后,对纵向压轮和横向插刀正常动作时的草方格铺设机器人振动状态进行了仿真.通过仿真,得到了牵引车、纵向铺设机构、横向铺设机构、纵向压轮和横向插刀质心的位移、速度以及加速度曲线.分析了这些曲线出现波动的原因,为进一步的优化提供了数据.通过试验,得到实际状态下的试验曲线,并与仿真曲线进行对照,证实了草方格铺设机器人仿真模型和仿真结果的合理性和可靠性.  相似文献   

实现连架杆给定角位移的机构综合方     

钱卫香  韩建友 《农业机械学报》2009,40(5):222-226

对于给定的两连架杆4组对应角位移,可综合得到无穷多个机构解,要求设计者快速、准确地从中选取位置点、综合出满足各项设计要求的最优机构比较困难.为此,根据映射理论,提出把无限的布氏曲线所形成的无穷多机构解表示在有限的区间内,进而通过机构解分析得到感兴趣的所有机构属性直观图,包括机构的类型分布、缺陷分布、最小传动角和杆长比等.同时,为避免位置点及机构选取的盲目性,可考虑施加约束条件构成可行机构解区间,在此区间上绘制机构性能分析图,并确定满足实际工程需要的最优机构解.  相似文献   

发酵方法对柿果醋中香气成分的影   总被引：5，自引：2，他引：3  

鲁周民  郑皓  赵文红  白卫东 《农业机械学报》2009,40(9):148-154

采用顶空固相微萃取法、结合气相色谱质谱联用技术,对自然发酵和常规发酵柿果醋中香气成分进行了分离与分析比较,分别从2种柿果醋中分离鉴定出挥发性化合物63种,均含有酯类、羧酸类、醇类、烃类、醛酮类、酚类及少量其他化合物.常规发酵柿果醋香气成分中含有酯类33.78%、醇类32.38%和烃类1.08%,高于自然发酵柿果醋的含量;自然发酵柿果醋香气成分中含有羧酸类61.25%、醛酮类9.66%和酚类6.13%,高于常规发酵柿果醋的含量.采用常规发酵法生产的柿果醋具有较好的感官质量.  相似文献   

基于倍四元数和Groebner基的6R机械手的位置反解     

倪振松  廖启征  魏世民  李瑞华  乔曙光 《农业机械学报》2009,40(2):190-194

提出了一般6R机械手的位置反解的新算法,该算法是把齐次变换矩阵转以倍四元数形式表示,建立了倍四元数形式的串联6R机械手运动学方程,再通过线性消元和两次应用分次字典序Groebner基消去5个变元,得到一个一元16次方程.此方法没有增根,是一种对空间任意尺寸6R机械手进行建模和求解的新算法.其中求解Groebner基采用了计算机代数系统进行有理数运算,目前的求解速度尚不是很高,需进一步改进.  相似文献   

永磁式涡流缓速器制动性能影响因素敏感性分析     

赵小波  姬长英  赵国柱 《农业机械学报》2009,40(10):18-23

在分析永磁式涡流缓速器制动力矩与结构参数关系的基础上,将均匀设计和回归分析方法引入到永磁式涡流缓速器制动性能影响因素敏感性分析中。以某型号的永磁式涡流缓速器为例,建立了制动力矩随转子鼓内半径、永磁体周向长度、气隙宽度、转子鼓轴向宽度和永磁体高度5个结构参数变化的回归模型,重点讨论了结构参数间交互作用以及各结构参数对制动力矩的影响程度,基于均匀试验设计和制动性能敏感性分析的结果,采用全排列法对结构参数进行了优化。  相似文献