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81.
半粒稻米直链淀粉测定方法的研究及应用   总被引:7,自引:0,他引:7  
杨金华  宋文昌 《作物学报》1992,18(5):366-372
本文提出一个简便易行的分析方法,用1粒稻米既可测出其中的直链淀粉含量,还可用以繁种,便于在育种早代选择优良个体、提高效率,加快进程。用本方法测得的直链淀粉含量与用中华人民共和国国标法GB_(7648-87),测得的结果经t检验,差异不显著。利用本法分析了F_1代种子及其亲本的直链淀粉含量,结果表明,在非糯品种与糯稻品种的两  相似文献   
82.
本文以黄淮地区6个夏大豆品种(系)通过双列杂交保留下来的F_3代材料,研究大豆6个形态性状的遗传特性.结果表明,株高、有效分枝数、主茎节数、主茎荚丛数和茎粗5个性状均符合加性—显性模型.而底荚高则存在非等位基因之间的互作效应.株高、有效分枝数、主茎节数和主茎荚丛数为部分显性,茎粗存在超显性现象.主茎节数和主茎荚丛数可能有相似的遗传特点.豫豆8号大豆带有较多的控制株高的显性基因,油84-30大豆带有较多的控制分枝和茎粗的显性基因,而尖顶大白角大豆控制主茎节数和美丛数的显性基因较多.  相似文献   
83.
小麦随机多交后代中抗条锈(Puccinia striiformis)性的选择   总被引:1,自引:1,他引:1  
冯锋  曾士迈 《作物学报》1991,17(2):107-114
本试验用16个被认为可能具有水平抗性的小麦品种为基础材料,采用乙烯利化学杀雄或太谷核不育为手段进行随机多交,以相对抗病性综合指数(RRCI)表示抗病性强度,研究了小麦条锈病水平抗性的遗传力及人工选择下的遗传进度,结果指出:1)随机多交的后代系统中,出现了一些抗条锈性显著高于优良亲本的系统。2)抗条锈性的遗传力较高:化  相似文献   
84.
大豆化学诱变育种及其规律的研究   总被引:12,自引:0,他引:12  
应用化学诱变剂处理大豆种子,对M_1代植株的生育及形态均有强烈的抑制作用.M_1代所产生的形态变异主要是由于化学物质扰乱了植株生理而产生生理损伤所致.在M_2代植株各性状中以分枝数、株高、单株荚数的遗传变异系数较大,说明这些性状选择的潜力是大的,通过选择容易达到预期目标.诱变M_3代绝大多数性状仍在分离.加强选择,能选出早熟、大粒、农艺性状好、丰产的新品系.  相似文献   
85.
基于遗传算法的泵汽蚀试验数据拟合   总被引:1,自引:2,他引:1  
唐平  李金伴  张荣标 《排灌机械》2002,20(1):37-39,46
文章对标准的遗传算法进行改进,采用了浮点数直接编码方式最优保留策略、算术交叉和非一致性变异算法等方法,并对泵汽蚀试验数据拟合问题进行分析,引入了此改进的遗传算法。最后给出了一组汽蚀试验数据,分析采用常规方法拟合和基于遗传算法拟合。结果说明了本文提出方法的可行性。  相似文献   
86.
This paper reports the outcomes of a deliberative workshop comparing land-use plans proposed by land-manager or domain experts with those derived using a computer-based decision support system (DSS). The DSS integrates four main components, a geographic information system, land-use systems simulation models, impact assessments and land-use planning tools. The land-use planning tools draw on the other components to generate and evaluate alternative patterns of land use and management. Since the land-use planning tools are based on multi-objective genetic algorithms (mGAs) it is possible to generate a range of alternative plans that define the structure of the trade-off between the objectives. The workshop tasked the delegates with specifying land-use plans that achieved the best compromise between two objectives known to be non-commensurable and conflicting. The nature of the best compromise was dependent on their individual perspectives. The delegates proposed allocations both as individuals and in researcher-facilitated sub-groups. The mGA allocations were then compared with those derived by delegates and were found to be broadly similar in performance. Differences in the range of allocations considered feasible were explained by the hard and soft constraints on allocations agreed between the delegates and articulated within the workshop process. The hypothesis that part of the difference in performance between the mGA and delegate allocations was due to the delegates blocking together fields with the same land use for convenience of management was proved. The analysis of the group allocations revealed that the decision-making process had failed to improve on the individual allocations. From these results it was concluded that there was a potential role for mGA based land-use planning tools in researching into, and deliberating on, the possible impacts of policy or other factors affecting land-use systems. It was further concluded that the tools should not be used in isolation since there was the need for stake-holder inputs to adequately define the range of feasible and practical land-use plans.  相似文献   
87.
Remotely sensed (RS) data is a major source to obtain spatialdata required for hydrological models. The challenge for thefuture is to obtain besides the more direct observable data(landcover, leaf area index, digital elevation model andevapotranspiration), non-visible data such as soilcharacteristics, groundwater depth and irrigation practices.In this study we have explore the option of using inversemodeling to obtain these non-RS-visible data. For a commandarea in Haryana, India, we applied for the 2000–2001 rabiseason a RS-GIS-combined inverse modeling approach to derivenon-RS-visible data required in the regional application ofhydrological models. A Genetic Algorithm loaded stochasticphysically based soil-water-atmosphere-plant model (SWAP) wasdeveloped for the inverse problem and used in the study. Theresults showed good agreement with the inventoried data suchas soil hydraulic properties, sowing dates, groundwaterdepths, irrigation practices and water quality. The deriveddata could be used to predict the state of the system at anytime in the cropping season, which can be used to evaluateoperational management strategies.  相似文献   
88.
遗传算法在离心泵叶片优化设计中的应用   总被引:2,自引:3,他引:2  
对遗传算法在流体机械优化设计中的应用现状作了较为全面的总结;提出了将遗传算法应用于离心泵叶片优化设计中,分析了遗传算法在离心泵优化设计中应用的可行性以及存在的问题;对离心泵优化设计的发展提出了一些新建议和尝试。  相似文献   
89.
遗传神经网络在温室黄瓜霜霉病预测中的应用   总被引:5,自引:0,他引:5  
在神经网络结构的优化、连续权重的训练中采用遗传算法的方法对日光温室黄瓜霜霉病进行预测,并对其发生程度进行了拟合,计算值与实际值接近,表明该模型具有良好的预测效果。  相似文献   
90.
Improving Drought Tolerance of Rice by Designed QTL Pyramiding   总被引:4,自引:0,他引:4  
Drought is the most important factor limiting rice yields in the rainfed areas of Asia. To overcome the problem, we developed a new strategy 'designed QTL pyramiding' to more efficiently develop drought tolerant (DT) rice cultivars. In the first phase of this strategy, we developed large numbers of introgression lines (ILs) in elite backgrounds using backcross (BC) breeding, each of which carries multiple genomic segments for improved DT from a known donor. Then, we genotyped all ILs with SSR markers to track the genomewide pattern of introgression in the DT ILs of 16 BC populations derived from crosses between 2 recipients (IR64 and Teqing) and four different donors. X^2 tests and linkage disequilibrium analyses of introgression in the DT ILs revealed significant frequency shifts at many loci across the genome and non-random associations at the multilocus level as a result of selection for DT in the ILs, which led us to the discovery of putative genetic networks underlying DT in the ILs. The networks each containing all DT loci detected in ILs from a BC population showed some interesting features.  相似文献   
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