The New Zealand apple genome mapping project   总被引：2，自引：0，他引：2  

Susan E. Gardiner  Ji Mei Zhu  Heather C. M. Whitehead  Charlotte Madie 《Euphytica》1994,77(1-2):77-81

Summary This project was initiated three years ago to support the New Zealand apple breeding programme at HortResearch and is funded by both the New Zealand Foundation for Research, Science and Technology and the New Zealand Apple and Pear Marketing Board. Our initial goal is to construct a linkage map comprising RFLP, RAPD and isoenzyme markers as well as characters of importance to our breeders and this will enable the breeders to use marker assisted selection to identify the most promising seedlings within progeny populations at an early age. Characters of interest in the shorter term include resistances to scab, powdery mildew, woolly apple aphid and silver leaf, and in the longer term more complex traits such as early and late fruit maturity, fruit quality characters, low temperature tolerance and rootstock influences such as dwarfing and precocity are under consideration. We are currently developing long-term plans for isolation of apple genes in association with other molecular biologists in Hort Research. We have used a cDNA library from apple flesh as a prolific source of RFLP probes and detect their hybridization to Southern blots using a chemiluminescent method. We have screened our mapping line of seedlings for more than 160 markers so far (1/3 RFLP, 2/3 RAPD). Detection of in situ hybridization of key RFLP probes to metaphase chromosome preparations for the purpose of associating marker linkage groups with physical chromosomes is by a digoxygenin or biotin linked immunoassay. The project has collaborative links to apple genome mapping projects in America and Europe.  相似文献   

Genetic Control of Vernalization, Day-length Response, and Earliness per se by Homoeologous Group-3 Chromosomes in Wheat   总被引：3，自引：0，他引：3  

H. Miura  A. J. WOrland 《Plant Breeding》1994,113(2):160-169

To identify homoeologous group-3 chromosomes that carry genes for vernalization, day-length responses, and earliness per se, a series of aneuploid lines (mono-somics and tetrasomics) and chromosome-substitution lines in ‘Chinese Spring’ (CS) were surveyed under different vernalization and day-length regimes in controlled environments. The results indicated that genes on all three chromosomes of group 3 can have striking effects on ear-emergence time. The replacement of CS 3B by its homologues in ‘Lutescens 62’ and ‘Cheyenne’ produced an increased insensitivity to vernalization, while 3B homologues from ‘Ceska Presivka’ gave CS a remarkable sensitivity to vernalization. This provided evidence for multiple allelism at a new Vrn locus on chromosome 3B. A negative association between gene dosage and day-length response was found in CS 3D which was thought to carry a gene for promoting insensitivity to day-length. The behaviour of CS monosomic 3A and CS (Timstein 3A), in reducing numbers of days to heading independently of environmental stimuli, suggested the presence of earliness per se genes on this chromosome.  相似文献   

Ploidy determination of some yam species (Dioscorea spp.) by flow cytometry and conventional chromosomes counting   总被引：1，自引：0，他引：1  

F. Gamiette  F. Bakry  G. Ano 《Genetic Resources and Crop Evolution》1999,46(1):19-27

Chromosomes counting and flow cytometry were used for assessing the ploidy level of various yam accessions of the INRA collection located in Guadeloupe. About 85 different clones were evaluated in the D. alata and D. cayenensis-rotundata and four other wild species related to D. cayenensis-rotundata. All the studied clones fitted in 4x, 6x and 8x ploidy levels. No diploid clone was found. Chromosomes counts and flow cytometry data led to the same results. The flow cytometry histograms for D. cayenensis-rotundata were not separated from those of its related wild species. Polyploidisation by fusion of 2n+n gamets was found to be unlikely for the two species D. cayenensis-rotundata and D. alata. Moreover, these results lead to the conclusion that the D. cayenensis-rotundata cultigens and the wild species analysed in this study may belong to the same gene pool.  相似文献   

玉米粗线期染色体G带及螺旋的研究     

何凤发  田丰炉 《西南大学学报(自然科学版)》1995,17(5):404-406

用风油精活体诱导玉米花粉母细胞粗线期染色体Ｇ带和螺旋的结果表明。Ｇ带带纹众多，分布于整要体上，带纹数目与染色体收缩程度相关。相同时期不同细胞的Ｇ带数量和位置稳定并可重复。同源染色体联会后的二阶体在纵向上的螺纹数与二价体的收缩程度有关，螺旋的方向具有多样性。  相似文献   

苎麻多倍体诱导研究——Ⅰ. 苎麻多倍体诱导的基础研究     

董延瑜  郑思乡  洪亚辉  任春梅  刘国民  邓明其  程尧楚 《湖南农业大学学报(自然科学版)》1992,(3)

5个苎麻品种经秋水仙碱处理后,在形态学和细胞学上均发生了明显变化。与对照株相比,变异株子叶肥厚,色深绿,叶表皮毛明显增多、变粗,幼叶表面气孔增大,而单位面积气孔数减少。染色体数目鉴定结果:正常株2n=2x=28,变异株为2n=4x=56,甚至出现2n=8x=112的重复加倍现象本研究探讨了苎麻诱变的细胞学基础、细胞分裂动态有丝分裂指数,确定了分裂盛期。同时还比较了各种诱变方法及其效果。借助光学和电子显微镜就秋水仙碱对苎麻诱变在形态学和细胞学上产生的效应进行了初步鉴定,为苎麻多倍体育种奠定了基础。  相似文献   

西农莎能山羊间性个体遗传性别研究     

詹铁生  田玉山  贾维珍 《西北农林科技大学学报(自然科学版)》1992,20(2):27-32

对西农莎能山羊4个年度繁殖的23头间性羊从解剖学、组织学和细胞遗传学三方面研究,发现了各种类型的间性羊,其中性逆转雄性间性及拟雌性假间性属山羊中首次提出的间性类型。它们的性染色体全部是XX型(遗传雌性)。因而间性基因是雄性化基因,使雌性个体向雄性转化。通常所见的异常雄性:短阴茎和性逆转雄性间性(包括小睾丸)是遗传雌性个体。  相似文献   

家猪高分辨G带染色体研究     

夏金星  施启顺  柳小春 《湖南农业大学学报(自然科学版)》1993,(2)

提供了家猪高分辨G 带染色体典型核型和色谱扫描图形,对家猪高分辨染色体相对长度与臂比指数进行了测量和分析,绘制了家猪高分辨G 带染色体577条带模式图,并按SKDP(1988)和ISCN(1981)对其带(亚带)进行了命名编号.采用色谱扫描法,增加了模式图绘制的客观性与方便性,所绘制的577条带模式图,是目前显带最丰富的模式图.  相似文献   

西洋参根尖染色体的核型分析   总被引：2，自引：0，他引：2  

任跃英  孙佰超 《吉林农业大学学报》1994,16(3):43-46

本文进行了西洋参根尖染色体的计数，并对其染色体核型进行了分析研究。结果表明，其染色体数目为４８条。按Ｌｅｖｅｎ等的分类原则，其核型为２ｎ＝２ｘ＝２０ｍ＋２ｂｓｍ＋２ｓｔ，属于Ｓｔａｂｂｉｎ核型的“２Ｂ”型。  相似文献   

芦苇花粉母细胞减数分裂和花粉粒发育的研究     

贾大勇  曹学军 《湖南农业大学学报(自然科学版)》1996,22(1):41-45

芦苇的染色体数目约为２ｎ＝７０．同一花序的不同部位，以顶端第三或第四小穗发育最快．花序上每节具有一短柄和一长柄小穗，二者发育时期基本一致．同一小穗内的不同小花，发育时期不同；而同一小花内的不同花药，发育时期基本一致；  相似文献   

油菜远缘杂交的遗传育种研究Ⅵ.芥菜型油菜几个基因的染色体组定位研究     

刘忠松  官春云 《湖南农业大学学报(自然科学版)》1997,(1)

芥菜型油菜×甘蓝型油菜种间杂种后代遗传研究表明，芥菜型油菜Ａ和Ｂ染色体组各有１对控制芥酸含量的等位基因，黄籽基因可能位于Ｂ组染色体，叶色受位于Ａ染色体组的１对具有剂量效应的基因控制．  相似文献