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一种基于Heat Map的地理标签数据可视化表达的研究 被引量:21
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作者 赵婷 华一新 +2 位作者 李响 李翔 杨飞 《测绘工程》 CSCD 2016年第6期28-32,共5页
地理标签数据是指蕴含在网页、照片、微博等信息媒介中的地理空间信息,其表现形式通常是经纬度坐标。通过分析地理标签数据的研究现状,对地理标签数据进行分类,并归纳地理标签数据具有属性数据非结构化、海量信息分布不均、强调位置相... 地理标签数据是指蕴含在网页、照片、微博等信息媒介中的地理空间信息,其表现形式通常是经纬度坐标。通过分析地理标签数据的研究现状,对地理标签数据进行分类,并归纳地理标签数据具有属性数据非结构化、海量信息分布不均、强调位置相对关系等特点。针对其中一个特点,通过对K-means算法进行改进,结合计算机图形学相关知识,利用热力图表达地理标签数据的分布特征。最后,通过与ArcGIS核密度图、散点图进行比较,得出该热力图算法具有表达效果明显、用户体验好等优点。 展开更多
关键词 地理标签数据 可视化 热力图 K-MEANS聚类
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云环境下基于MapReduce的用户聚类研究与实现 被引量:7
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作者 樊同科 《电子设计工程》 2016年第10期35-37,41,共4页
基于大数据背景下海量数据人们无法理解,聚类效率低下等问题,采用MapReduce编程模型将Canopy聚类算法和K-means聚类算法在云环境中相结合,使之能够充分利用Hadoop集群的计算和存储能力。以淘宝网上海量的购买用户聚类作为应用背景,通过... 基于大数据背景下海量数据人们无法理解,聚类效率低下等问题,采用MapReduce编程模型将Canopy聚类算法和K-means聚类算法在云环境中相结合,使之能够充分利用Hadoop集群的计算和存储能力。以淘宝网上海量的购买用户聚类作为应用背景,通过使用Hadoop平台的数据挖掘组件Mahout对用户聚类进行了实例研究,并给出了使用Mahout进行挖掘的一般步骤。结果表明,基于MapReduce的聚类算法在大规模数据集上具有较好的聚类质量和运行速度。 展开更多
关键词 HADOOP mapREDUCE 聚类算法 Mahout
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基于MapReduce的SimRank算法在图聚类中的应用 被引量:3
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作者 冷泳林 鲁富宇 《电子设计工程》 2015年第6期9-11,15,共4页
由Jeh和Widom提出的Sim Rank算法是一种普适"结构相似度"计算模型。由于Sim Rank算法采用迭代方式计算图节点间相似性,因此时间复杂度和空间复杂度都非常高。随着数据量的激增,单机运算能力不能满足大规模数据的计算要求。本... 由Jeh和Widom提出的Sim Rank算法是一种普适"结构相似度"计算模型。由于Sim Rank算法采用迭代方式计算图节点间相似性,因此时间复杂度和空间复杂度都非常高。随着数据量的激增,单机运算能力不能满足大规模数据的计算要求。本文提出了基于Map Reduce计算模型的分布式Sim Rank算法,利用该算法对RDF图进行相似度度量,然后利用分布式的AP聚类算法对图节点进行聚类分析。实验结果表明,该方法能够高效的完成图节点的相似度度量,实现图的有效聚类。 展开更多
关键词 SIM RANK map REDUCE RDF AP聚类
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低质量图像基于散射图SEM估计的MAP像素聚类方法 被引量:3
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作者 薛景浩 章毓晋 林行刚 《电子学报》 EI CAS CSCD 北大核心 1999年第7期95-98,共4页
直方图是最常用的图像灰度统计分布的表示方法,二维直方图包括共生矩阵,灰度边界值散射图,灰度平均灰度散射图等.本文提出了一种采用SEM算法完成对灰度平均灰度的二维正态分布假设的参数估计,然后采用最大后验概率(MP... 直方图是最常用的图像灰度统计分布的表示方法,二维直方图包括共生矩阵,灰度边界值散射图,灰度平均灰度散射图等.本文提出了一种采用SEM算法完成对灰度平均灰度的二维正态分布假设的参数估计,然后采用最大后验概率(MPA)准则进行像素无监督聚类的图像分割算法.测试结果显示,我们的算法性能良好,尤其是对低对比度、有阴影和重噪声的低质量图像的分割效果要远优于其他基于散射图的阈值化方法. 展开更多
关键词 像素聚类 图像阈值化 二维直方图 SEM算法 map准则
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一种基于MapReduce的知识聚类与统计机制 被引量:1
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作者 徐小龙 李永萍 《电子与信息学报》 EI CSCD 北大核心 2016年第1期202-208,共7页
网络文献知识库中的海量资源及其分类的粗粒度,导致学习者容易在文献检索和阅读过程出现认知迷航和知识过载问题。该文提出一种基于Map Reduce的知识聚类与统计机制:首先,提出基于Map Reduce的共现矩阵构建算法MR-Co Matrix;其次,将共... 网络文献知识库中的海量资源及其分类的粗粒度,导致学习者容易在文献检索和阅读过程出现认知迷航和知识过载问题。该文提出一种基于Map Reduce的知识聚类与统计机制:首先,提出基于Map Reduce的共现矩阵构建算法MR-Co Matrix;其次,将共现矩阵与相似度系数结合构建相似度矩阵;然后,通过Z Scores对相似度矩阵进行标准化;最后,使用离差平方和法(Ward,s method)对相似度矩阵进行聚类,生成树状的知识聚类谱系图;基于聚类结果,提出基于Map Reduce的知识文献统计算法MR-Statistics,对每个分类的知识属性进行统计。实验结果表明:将MR-Co Matrix和MR-Statistics方法应用于网络文献知识库进行知识聚类和统计,达到较理想的聚类精度和计算效率,实现了细粒度知识聚类和多维统计,同时减少了时间开销。 展开更多
关键词 数据挖掘 聚类 知识 共现矩阵 统计 map REDUCE
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基于L-ISOMAP降维的快速模糊聚类算法 被引量:2
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作者 孙丽萍 丁男 +1 位作者 王云中 马洪连 《计算机工程与应用》 CSCD 北大核心 2011年第24期182-185,190,共5页
模糊C-均值聚类算法是非监督模式识别中广泛应用的算法之一。但是,FCM算法在迭代过程中需要大量的计算,尤其当特征向量维数较高时,使用聚类分堆训练,不仅效率低下,还有可能导致"维数灾难"。针对该问题,分析模糊C-均值聚类算... 模糊C-均值聚类算法是非监督模式识别中广泛应用的算法之一。但是,FCM算法在迭代过程中需要大量的计算,尤其当特征向量维数较高时,使用聚类分堆训练,不仅效率低下,还有可能导致"维数灾难"。针对该问题,分析模糊C-均值聚类算法在高维特征分析过程中,聚类中心的求解问题是一个np-hard问题,为了提高模糊C-均值聚类算法在高维特征分析中的实时性与有效性,结合界标等距映射(L-ISOMAP)算法,提出了改进算法FCM-LI,先对样本初步分析,利用聚类结果及样本数据相关性,使用界标等距映射(L-ISOMAP)算法降维,在此基础上进一步分析,获得最终分析结果。通过实验证明,FCM-LI算法在高维数据分析过程中的有效性与实时性。 展开更多
关键词 模糊C-均值聚类 等距映射 非线性降维
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基于改进的Map/Reduce及模式空间划分的数据挖掘 被引量:4
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作者 刘骞 陈明 《微电子学与计算机》 CSCD 北大核心 2011年第8期140-142,共3页
为通过Map/Reduce基于键/值对以处理数据集与模式集的多对多的对应关系的方式实现数据挖掘,解决在较复杂的类型的模式的挖掘中存在的由组合爆炸导致的模式集过大的问题,提出了通过模式空间划分实现将处理数据集与模式集的对应关系的问... 为通过Map/Reduce基于键/值对以处理数据集与模式集的多对多的对应关系的方式实现数据挖掘,解决在较复杂的类型的模式的挖掘中存在的由组合爆炸导致的模式集过大的问题,提出了通过模式空间划分实现将处理数据集与模式集的对应关系的问题转化为处理数据集与子模式集的集合的对应关系的问题的方法,并对Map/Reduce集群的调度机制及组织、处理键/值对的方式进行了改进,增强了Map/Reduce执行模式挖掘任务的能力.在Map/Reduce集群上采用该思路实现某些较复杂类型的模式的挖掘算法时的并行度高于Map/Reduce化的传统算法. 展开更多
关键词 改进的map/Reduce 集群 多对多映射 模式空间划分 模式编码 数据挖掘
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大数据环境下基于MapReduce的网络舆情热点发现 被引量:15
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作者 王书梦 吴晓松 《软件》 2015年第7期108-113,共6页
大数据环境下的网络舆情分析更侧重于在海量数据的采集、存储、清洗和文本聚类,因此传统的仅依据数据统计的舆情分析方法不再适用。文章对大数据网络舆情分析的相关文献进行总结研究,归纳出网络舆情分析的基本流程框架,并阐明了在大数... 大数据环境下的网络舆情分析更侧重于在海量数据的采集、存储、清洗和文本聚类,因此传统的仅依据数据统计的舆情分析方法不再适用。文章对大数据网络舆情分析的相关文献进行总结研究,归纳出网络舆情分析的基本流程框架,并阐明了在大数据环境下网络舆情分析中文本聚类的各个阶段如何运用Map Reduce进行分布式计算,以此提高网络舆情分析的准确度与及时性。 展开更多
关键词 大数据 舆情热点 map REDUCE 文本聚类
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Background dominant colors extraction method based on color image quick fuzzy c-means clustering algorithm 被引量:2
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作者 Zun-yang Liu Feng Ding +1 位作者 Ying Xu Xu Han 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第5期1782-1790,共9页
A quick and accurate extraction of dominant colors of background images is the basis of adaptive camouflage design.This paper proposes a Color Image Quick Fuzzy C-Means(CIQFCM)clustering algorithm based on clustering ... A quick and accurate extraction of dominant colors of background images is the basis of adaptive camouflage design.This paper proposes a Color Image Quick Fuzzy C-Means(CIQFCM)clustering algorithm based on clustering spatial mapping.First,the clustering sample space was mapped from the image pixels to the quantized color space,and several methods were adopted to compress the amount of clustering samples.Then,an improved pedigree clustering algorithm was applied to obtain the initial class centers.Finally,CIQFCM clustering algorithm was used for quick extraction of dominant colors of background image.After theoretical analysis of the effect and efficiency of the CIQFCM algorithm,several experiments were carried out to discuss the selection of proper quantization intervals and to verify the effect and efficiency of the CIQFCM algorithm.The results indicated that the value of quantization intervals should be set to 4,and the proposed algorithm could improve the clustering efficiency while maintaining the clustering effect.In addition,as the image size increased from 128×128 to 1024×1024,the efficiency improvement of CIQFCM algorithm was increased from 6.44 times to 36.42 times,which demonstrated the significant advantage of CIQFCM algorithm in dominant colors extraction of large-size images. 展开更多
关键词 Dominant colors extraction Quick clustering algorithm clustering spatial mapping Background image Camouflage design
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基于Mapping方法的京沪高速铁路区域景观规划分析 被引量:10
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作者 邓敬 邱建 殷荭 《中国园林》 北大核心 2019年第5期96-101,共6页
高速铁路的快速发展在改变人们出行方式、缩短“时空距离”、提高工作效率的同时,也在急剧改变着城市景观风貌和区域景观格局,这为风景园林规划设计提出了新的研究课题,需要拓宽研究视野、拓展研究方法。景观都市主义的Mapping方法,一... 高速铁路的快速发展在改变人们出行方式、缩短“时空距离”、提高工作效率的同时,也在急剧改变着城市景观风貌和区域景观格局,这为风景园林规划设计提出了新的研究课题,需要拓宽研究视野、拓展研究方法。景观都市主义的Mapping方法,一直在研究如何让景观更有效地介入空间、生态和社会的发展进程,用多种方式对空间或地理坐标基础上的信息进行可视化操作。通过Mapping的“层-组-群”方法,以穿越与连接了多地域、多层次区域景观的京沪高速铁路为研究对象,研究京沪高铁沿线的相关层级信息、叠组的关联与群化关系,展示出网络化与可视性的景观因素与特征。研究结果旨在为跨区域高速铁路的景观规划提供参考。 展开更多
关键词 风景园林 景观都市主义 区域景观规划 mapping方法 “层-组-群” 京沪高铁
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Clustering of Major Genes Conferring Blast Resistance in a Durable Resistance Rice Cultivar Gumei 2 被引量:4
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作者 WuJian-li CHAIRong-yao +4 位作者 FANYe-yang LIDe-bao ZHENGKang-le HeiLEUNG ZHUANGJie-yun 《Rice science》 SCIE 2004年第4期161-164,共4页
By using 304 recombinant inbred lines derived from indica rice cross Zhong 156/Gumei 2, a linkage map consisting of 177 marker loci and covering 12 rice chromosomes was constructed and employed for mapping genes confe... By using 304 recombinant inbred lines derived from indica rice cross Zhong 156/Gumei 2, a linkage map consisting of 177 marker loci and covering 12 rice chromosomes was constructed and employed for mapping genes conferring blast resistance in rice. Genomic location of gene Pi25(t) conferring neck blast resistance to the Chinese isolate 92-183 (race ZC15) was verified to be located between markers A7 and RG456 on chromosome 6, with genetic distances of 1.7 cM and 1.5 cM to A7 and RG456, respectively. Leaf blast resistance of Gumei 2 to the Philippine isolate Ca89 (lineage 4) was found to be controlled by a single gene. The gene tentatively designated as Pi26(\) was located between makers B10 and R674 on chromosome 6, with genetic distances of 5.7 cM and 25.8 cM to B10 and R674 respectively. Resistant alleles at both gene loci were derived from Gumei 2, indicating an existence of resistance gene cluster in Gumei 2. 展开更多
关键词 blast resistance molecular mapping gene cluster RICE
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大数据挖掘中的MapReduce并行聚类优化算法研究 被引量:21
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作者 吕国 肖瑞雪 +1 位作者 白振荣 孟凡兴 《现代电子技术》 北大核心 2019年第11期161-164,共4页
针对传统数据挖掘算法只适用于小规模数据挖掘处理,由于数据规模不断增大,其存在计算效率低、内存不足等问题,文中将MapReduce用于数据挖掘领域,对大数据挖掘中的MapReduce进行了并行化改进,并设计相应的并行化实现模型,以期满足大数据... 针对传统数据挖掘算法只适用于小规模数据挖掘处理,由于数据规模不断增大,其存在计算效率低、内存不足等问题,文中将MapReduce用于数据挖掘领域,对大数据挖掘中的MapReduce进行了并行化改进,并设计相应的并行化实现模型,以期满足大数据分析需求,完成低成本、高性能的数据并行挖掘与处理。 展开更多
关键词 大数据 mapREDUCE 并行化处理 聚类算法 数据挖掘 map任务
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Improved clustering method based on artificial immune 被引量:1
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作者 Lin Zhu Bo Li 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第6期1111-1115,共5页
An improved clustering method based on artificial immune is proposed. To obtain the better initial solution, the initial antibody network is introduced by self organizing map (SOM) method. In the process of the clus... An improved clustering method based on artificial immune is proposed. To obtain the better initial solution, the initial antibody network is introduced by self organizing map (SOM) method. In the process of the clustering iteration, a series of optimization and evolution strategies are designed, such as clustering satisfaction, the threshold design of scale compression, the learning rate, the clustering monitoring points and the clustering evaluations indexes. These strategies can make the clustering thresholds be quantified and reduce the operator’s subjective factors. Thus, the local optimal and the global optimal clustering simultaneously are proposed by the synthesized function of these strategies. Finally, the experiment and the comparisons demonstrate the proposed method effectiveness. 展开更多
关键词 artificial immune system (AIS) clusterING self organizing map (SOM).
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Clustering Seismic Activities Using Linear and Nonlinear Discriminant Analysis 被引量:4
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作者 H Serdar Kuyuk Eray Yildirim +1 位作者 Emrah Dogan Gunduz Horasan 《Journal of Earth Science》 SCIE CAS CSCD 2014年第1期140-145,共6页
Identification and classification of different seismo-tectonic events with similar character- istics in a region of interest is one of the most important subjects in seismic hazard studies. In this study, linear and n... Identification and classification of different seismo-tectonic events with similar character- istics in a region of interest is one of the most important subjects in seismic hazard studies. In this study, linear and nonlinear discriminant analyses have been applied to classify seismic events in the vicinity of Istanbul. The vertical components of the digital velocity seismograms are used for seismic events with magnitude (Md) between 1.8 and 3.0 that occurred between 2001 and 2004. Two, time dependent pa- rameters, complexity and S/P peak amplitude ratio are selected as predictands. Linear, quadratic, diag- linear and diagquadratic discriminant functions are investigated. Accuracy of methods with an addi- tional adjusted quadratic models are 96.6%, 96.6%, 95.5%, 96.6%, and 97.6%, respectively with a vari- ous misclassified rate for each class. The performances of models are justified with cross validation and resubstitution error. Although all models remarkably well performed, adjusted quadratic function achieved the best success rate with just 4 misclassified events out of 179, even better compared to com- plex methods such as, self organizing method, k-means, Gaussion mixture models that applied to same dataset in literature. 展开更多
关键词 discriminant analysis clustering analysis self organizing map K-MEANS Gaussion mix- ture models.
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Mapping the hotspots and coldspots of ecosystem services in conservation priority setting 被引量:20
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作者 LI Yingjie ZHANG Liwei +4 位作者 YAN Junping WANG Pengtao HU Ningke CHENG Wei FU Bojie 《Journal of Geographical Sciences》 SCIE CSCD 2017年第6期681-696,共16页
Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services (ES) conservation. However, little research has identified and tested the compactness and effic... Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services (ES) conservation. However, little research has identified and tested the compactness and efficiency of their ES hotspots and coldspots, which may weaken the effectiveness of ecological conservation. In this study, based on the RUSLE model and Getis-Ord Gi* statistics, we quantified the variation of annual soil conservation services (SC) and identified the statistically significant hotspots and coldspots in Shaanxi Province of China from 2000 to 2013. The results indicate that, 1) areas with high SC presented a significantly increasing trend as well, while areas with low SC only changed slightly; 2) SC hotspots and coldspots showed an obvious spatial differentiation--the hotspots were mainly spatially ag- gregated in southern Shaanxi, while the coldspots were mainly distributed in the Guanzhong Basin and Sand-windy Plateau; and 3) the identified hotspots had the highest capacity of providing SC, with 29.6% of the total area providing 59.7% of the total service. In contrast, the coldspots occupied 46.3% of the total area, but only provided 17.2% of the total SC. In addition to conserving single ES, the Getis-Ord Gi* statistics method can also help identify multi-functional priority areas for conserving multiple ES and biodiversity. 展开更多
关键词 ecosystem services mapping soil conservation spatial clustering Getis-Ord Gi* statistics Shaanxi Province
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基于MAP-REDUCE的大数据不一致性解决算法
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作者 范令 《微型机与应用》 2015年第15期18-21,25,共5页
大数据时代悄然而至,数据质量也引起人们的关注。在提高数据质量方面,很重要的一部分是解决数据不一致性问题。针对大数据情况下的数据不一致问题,本文提出了在MAP-REDUCE框架下的聚类算法。本文在MAP-REDUCE框架下对K-MEDOIDS聚类算法... 大数据时代悄然而至,数据质量也引起人们的关注。在提高数据质量方面,很重要的一部分是解决数据不一致性问题。针对大数据情况下的数据不一致问题,本文提出了在MAP-REDUCE框架下的聚类算法。本文在MAP-REDUCE框架下对K-MEDOIDS聚类算法进行了改进,增强了算法的适用性和精确性,并通过仿真实验验证了在大数据环境下该算法的并行性和有效性。 展开更多
关键词 大数据 数据质量 数据不一致性 map-REDUCE 聚类算法
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Pattern recognition of seismogenic nodes using Kohonen selforganizing map: example in west and south west of Alborz region in Iran
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作者 Mostafa Allamehzadeh Soma Durudi Leila Mahshadnia 《Earthquake Science》 CSCD 2017年第3期145-155,共11页
Pattern recognition of seismic and mor- phostructural nodes plays an important role in seismic hazard assessment. This is a known fact in seismology that tectonic nodes are prone areas to large earthquake and have thi... Pattern recognition of seismic and mor- phostructural nodes plays an important role in seismic hazard assessment. This is a known fact in seismology that tectonic nodes are prone areas to large earthquake and have this potential. They are identified by morphostructural analysis. In this study, the Alborz region has considered as studied case and locations of future events are forecast based on Kohonen Self-Organized Neural Network. It has been shown how it can predict the location of earthquake, and identifies seismogenic nodes which are prone to earthquake of M5.5+ at the West of Alborz in Iran by using International Institute Earthquake Engineering and Seismology earthquake catalogs data. First, the main faults and tectonic lineaments have been identified based on MZ (land zoning method) method. After that, by using pattern recognition, we generalized past recorded events to future in order to show the region of probable future earthquakes. In other word, hazardous nodes have determined among all nodes by new catalog generated Self-organizing feature maps (SOFM). Our input data are extracted from catalog, consists longitude and latitude of past event between 1980-2015 with magnitude larger or equal to 4.5. It has concluded node D1 is candidate for big earthquakes in comparison with other nodes and other nodes are in lower levels of this potential. 展开更多
关键词 clustering - Earthquake prediction ~ Self-organizing feature maps (SOFM)
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The Uniform Convergence Topology On Multi-valued Mapping Space
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作者 辛玉梅 谢鸿政 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1996年第2期1-5,共5页
Some convergences of topology are discussed. The definitions of almost uniform convergence topology and compatible topology are given. It is shown that the quasiuniform convergence and generalized uniform convergence ... Some convergences of topology are discussed. The definitions of almost uniform convergence topology and compatible topology are given. It is shown that the quasiuniform convergence and generalized uniform convergence have no compatible topology,but the almost uniform convergence has compatible topology. Moreover, the description of all uniform convergence limits and their mutual relation are investigated[1]. 展开更多
关键词 ss: TOPOLOGICAL SPACE MULTI-VALUED mapping limit-cluster line
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Customer Segmentation of Credit Card Default by Self Organizing Map
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作者 Hui Wu Chang-Chun Wang 《American Journal of Computational Mathematics》 2018年第3期197-202,共6页
In this paper we applied the technique of Self Organizing Map (SOM) to segment individuals based on their credit information. SOM is an unsupervised machine learning method that reduces data complexity and dimensional... In this paper we applied the technique of Self Organizing Map (SOM) to segment individuals based on their credit information. SOM is an unsupervised machine learning method that reduces data complexity and dimensionality while keeping sits original topology, which is superior to other dimension reduction methods especially when features in data have unclear nonlinear relations. Through this method we provide more clear and intuitive segmentation that other traditional methods cannot achieve. 展开更多
关键词 Self ORGANIZING map clustering Machine Learning CREDIT DEFAULT
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Cytogenetic Mapping of Disease Resistance Genes and Analysis of Their Distribution Features on Chromosomes in Maize 被引量:2
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作者 Li Li-jia, Song Yun-chun Key Laboratory of MOE for Plant Developmental Biology, Wuhan University, Wuhan 430072, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第04A期1167-1172,共6页
Cytogenetic maps of four clusters of disease resistance genes were generated by ISH of the two RFLP markers tightly linked to and flanking each of maize resistance genes and the cloned resistance genes from other plan... Cytogenetic maps of four clusters of disease resistance genes were generated by ISH of the two RFLP markers tightly linked to and flanking each of maize resistance genes and the cloned resistance genes from other plant species onto maize chromosomes, combining with data published before. These genes include Helminthosporium turcium Pass resistance genes Ht1, Htn1 and Ht2, Helminthosporium maydis Nisik resistance genes Rhm1 and Rhm2, maize dwarf mosaic virus resistance gene Mdm1, wheat streak mosaic virus resistance gene Wsm1, Helminthosporium carbonum ULLstrup resistance gene Hml and the cloned Xanthomonas oryzae pv. Oryzae resistance gene Xa21 of rice, Cladosporium fulvum resistance genes Cf-9 and Cf-2.1 of tomato,and Pseudomonas syringae resistance gene RPS2 of Arabidopsis. Most of the tested disease resistance genes located on the four chromosomes, i.e., chromosomes1, 3, 6 and 8, and they closely distributed at the interstitial regions of these chromosomal long arms with percentage distances ranging 31.44(±3.72)-72.40(±3.25) except for genes Rhm1, Rhm2, Mdm1 and Wsm1 which mapped on the satellites of the short arms of chromosome6. It showed that the tested RFLP markers and genes were duplicated or triplicated in maize genome. Homology and conservation of disease resistance genes among species, and relationship between distribution features and functions of the genes were discussed. The results provide important scientific basis for deeply understanding structure and function of disease resistance genes and breeding in maize. 展开更多
关键词 MAIZE four clusters of resistance genes in situ hybridization cytogenetic mapping distribution features
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