共查询到19条相似文献,搜索用时 421 毫秒
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陶建基 《江西农业大学学报》1987,(2)
果蝇属(Drosophila)分为八个亚属,共有九百多个种。在 Sophophora 亚属中的普通果蝇(D.melanogaster)是遗传学及细胞学研究中应用得最多的一个种。例如 果蝇的唾腺染色体,不仅是大学遗传学实验和中学生物学实验用作观察巨形染色体(macro chromoso-me)和多线染色体(Polytene chromosome)的典型材料,而且在遗传学上,可以根据唾腺 相似文献
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盐酸解离是果蝇唾腺染色体制片中的关键步骤,研究了盐酸浓度与处理时间对染色体解聚合与制片效果的影响.解离不充分时,压片后唾腺染色体仍团聚在一起;解离过度时,染色体结构受损,二者都达不到制片的要求.用2 mol/L盐酸处理20 min或者用3 mol/L盐酸处理15 min,染色体解聚适度,染色体分散,染色体臂及横纹均清晰可见,制片效果理想.用3 mol/L盐酸解离,所需时间短,更适合于制片观察. 相似文献
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果蝇唾腺染色体为多线染色体,其上的每一条横纹带就是一个具有多个相同DNA序列的基因集合体,这个集合体至少相当于一个基因的克隆。本研究利用8.8NHCl打断果蝇唾腺染色体的间带区,使每条横纹带相互分离,实现了天然基因克隆的切割。本方法简单易行,为开发转基因动物和转基因植物提供了新的研究途径。 相似文献
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采用CMA(chromomycin A3,CMA)和DAPI(4′,6-diamidino-2-phenylindole,DAPI)双荧光染色方法,分析了沙田柚实生苗根尖染色体的荧光带型和核型结构。结果表明:沙田柚实生苗染色体存在6种不同类型的CMA荧光带型,即染色体臂两端及近着丝粒部位均有荧光带(A型)、染色体臂一端及近着丝粒部位共有2处荧光带(B型)、染色体臂两端有荧光带(C型)、仅染色体臂一端有荧光带(D型)、染色体臂一端有较弱荧光带(E型)及染色体上无荧光带(F型)。大部分实生苗染色体的CMA带型公式是2n=18=3A+1B+2C+4D+8F,其他实生苗的染色体组成是2n=18=3A+1B+2C+4D+4E+4F、3A+1B+2C+4D+8E、2n=18=2A+2B+2C+4D+8F和2n=18=2A+2B+2C+4D+4E+4F。染色体的DAPI带型与CMA带型有相反带纹,并存在不同程度的弱带。同时观察到体细胞染色体联会现象和2~4个染色体脆性位点。 相似文献
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Development of EST-PCR Markers for the Chromosome 4V of Haynaldia villosa and Their Application in Identification of 4V Chromosome Structural Aberrants 下载免费PDF全文
ZHAO Ren-hui WANG Hai-yan JIA Qi XIAO Jin YUAN Chun-xia ZHANG Ya-jun HU Qing-shan WANG Xiu-e 《农业科学学报》2014,13(2):282-289
EST-PCR based molecular markers specific for alien chromosomes are not only useful for the detection of the introgressed alien chromatin in the wheat background, but also provide evidence of the syntenic relationship between homoeologous chromosomes. In the present study, in order to develop high density and evenly distributed molecular markers on chromosome 4V of Haynaldia villosa, a total of 607 primer pairs were designed according to the EST sequences, which were previously located in 23 different bins of wheat chromosomes 4A, 4B and 4D. By using the Triticum durum-H, villosa amphiploid and T. aestivum-H, villosa alien chromosome lines involving chromosome 4V, it was found that 9.23% of the tested primers could amplify specific bands for chromosome 4V. Thirty and twenty-six specific markers could be assigned to chromosome arms 4VS and 4VL, respectively. These 4V specific markers provided efficient tools for the characterization of structural variation involving the chromosome 4V as well as for the selection of useful genes located on chromosome 4V in breeding programs. 相似文献
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Hao-jie SUN Jing-jing SONG Jin XIAO Tao XU Xing WEI Chun-xia YUAN Ai-zhong CAO Li-ping XING Hai-yan WANG Xiu-e WANG 《农业科学学报》2018,17(8):1720-1726
Expressed sequence tags-derived polymerase chain reaction (EST-PCR) molecular markers specific for alien chromosomes can be used to not only monitor the introgressed alien chromatin in wheat background, but also provide the evidence of the syntenic relationship between homoeologous chromosomes. In the present study, in order to develop high density and evenly distributed molecular markers specific for chromosome 6VL of Dasypyrum villosum, 297 primer pairs were designed based on the expressed sequence tags (EST) sequences, which were previously mapped in different bins of the long arms of wheat homoeologous 6AL, 6BL, and 6DL. By using the Triticum aestivum, D. villosum, T. durum-D. villosum amphiploid, and T. aestivum-D. villosum alien chromosome lines involving chromosome 6V, it was found that 32 (10.77%) primers could amplify specific bands for chromosome 6V, and 31 could be allocated to chromosome arm 6VL. These 6VL specific markers provided efficient tools for the characterization of structural variation involving the chromosome 6VL in common wheat background as well as for the selection of useful genes located on 6VL in breeding programs. 相似文献
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秋水仙素诱导细叶百合多倍体研究 总被引:2,自引:0,他引:2
为获得具有优良观赏性状和农艺性状的细叶百合四倍体植株,并为百合的新品种选育提供性状优良的杂交亲本,以细叶百合种子(2n=2x=24)为试验材料,通过秋水仙素浸泡种子的方法,研究了不同秋水仙素浓度和处理时间对细叶百合染色体加倍的诱导效果.结果表明:以0.1%秋水仙素处理24 h诱导效果最佳,变异率最高,达30%.经根尖染色体鉴定,四倍体植株染色体数目为2n=4x=48.四倍体植株气孔密度减少,气孔增大;前期生长势缓慢,叶片短缩增宽,叶色加深;后期生长健壮,叶片增大明显.通过对经秋水仙素诱导获得的变异植株形态、气孔的观察测定以及染色体倍性鉴定,成功获得了细叶百合的多倍体植株. 相似文献
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为探讨性别、年龄和季节对麋鹿(Elaphurus davidianus)行为的影响,2006年9月-2007年10月,作者采用焦点取样法和瞬时记录法,将麋鹿昼间活动归为采食、饮水、运动、休息、警觉、其他行为等六大类型,每月6-8 d对湖北石首麋鹿国家级自然保护区麋鹿种群的昼间活动时间分配进行了跟踪观察.结果表明:麋鹿有晨、昏两个采食高峰和一个午间休息期,各种行为类型所占比例依次是:休息53.40%(±5.59%)、采食22.36(±8.34%)、运动11.23%(±0.63%)、警觉5.03%(±1.76%)、其他行为4.42%(±2.06%),饮水2.65%(±0.74%).不同季节,时间分配变化明显.非参数Kruskal Wallis H检验结果显示(n=120),季节、年龄和性别显著影响麋鹿的活动时间分配.除运动行为(x2=16.856,df=3,P>0.05)和饮水行为(x2=7.667,df=3,P>0.05)无显著差异外,采食(x2=15.657,df=3,P<0.01)、休息(x2=13.173,df=3,P<0.01)、警觉(x2 =13.887,df=3,P<0.01)和其他行为(x2=16.317,df=3,P<0.01)在不同季节所占时间百分比均有极显著差异.对不同性别年龄组的活动时间分配采用两个独立样本的Mann-Whitney U检验,各性别-年龄组间的运动行为所占时间比例有极显著差异(P<0.01),雄鹿与雌鹿之间的警觉行为有极显著差异(P<0.01),雄鹿花较多时间用于警觉.幼鹿与成年鹿及亚成年鹿之间的采食行为时间有极显著差异(P<0.01).不同性别、年龄组在不同季节的昼间活动时间分配的差异采用方差(ANOVA)分析后发现:所有年龄组,夏季与冬季饮水、春季与夏季警觉均存在显著性差异(P<0.01);成体和亚成体麋鹿,春季与冬季警觉、夏季与冬季运动均存在显著性差异(P<0.01). 相似文献
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Molecular and biological characterization of melon-infecting squash leaf curl China virus in China 下载免费PDF全文
It has been reported that squash leaf curl China virus (SLCCNV) infects some Cucurbitaceae crops except for melon (Cucumis melo L.). A new disease of melon exhibiting severe leaf curl and dwarfing was observed in Hainan Province of China. In this study, the pathogen was identified as SLCCNV through biological and molecular characterization. The isolate (SLCCNV-HN) possess a bipartite genome, DNA-A (HM566112.1) with the highest nucleotide identity (99%) to SLCCNV-Hn (MF062251.1) pumpkin and SLCCNV-Hn61 (AM260205.1) squash isolates from China, whereas DNA-B (HM566113.1) with the highest nucleotide identity (99%) to SLCCNV-Hn (MF062252.1). Phylogenetic analyses based on the full-length SLCCNV-HN DNA-A and -B sequences indicated that SLCCNV-HN melon isolate is clustered with SLCCNV-Hn pumpkin, SLCCNV-Hn61 and SLCCNV-SY squash isolates from southern China, forming an independent cluster. Infectious clone of SLCCNV-HN was constructed and the melon plants were inoculated and the infection rate is 100%, the systemic symptoms in melon showed identical to those of melon plants infected in fields. Additionally, melon plants transmission of this virus by Bemisia tabaci with a transmission rate of 95% (19/20) showed leaf curl and dwarf symptoms 15 days post transmission, thereby fulfilling Koch's postulates. Analysis of genomic organization and phylogenetic trees indicated that SLCCNV-HN melon isolate belongs to the Begomovirus genus. To the best of our knowledge, this is the first characterization of melon-infecting SLCCNV through its genome, infectious clone and transmission. 相似文献
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新疆野苹果的不同种下类型染色体核型分析 总被引:1,自引:0,他引:1
【目的】新疆野苹果(Malus sieversii)是新疆伊犁地区的主要野生苹果种质资源,是中国苹果资源中的独特分支,加强该资源的研究对保护苹果种质资源的丰富性具有重大意义。对新疆野苹果的不同种下类型进行细胞学分类,探讨新疆野生苹果种下类型之间的亲缘关系,为新疆野苹果资源的保护、开发与利用提供科学依据。【方法】以采自伊犁的新疆野苹果24个种下类型为研究对象,在4月初至4月中旬,选取其幼嫩的茎尖,采用改进的适合新疆野苹果核型分析的染色体制片方法进行压片,并根据不同种下类型染色体数目及其相对长度、平均臂比等核型指标,观察分析新疆野苹果24个种下类型染色体的核型特征。【结果】(1)新疆野苹果24个种下类型均为二倍体,染色体数目为34条,所有种质染色体相对长度平均值为3.23 μm,属小染色体。从着丝点位置观察,多数类型均含有不同数量的m和sm染色体,个别类型只有m染色体,核型公式为2n=2x=34=34m、2n=2x=34=30m+4sm、2n=2x=34=28m+6sm、2n=2x=34=32m+2sm等4种类型。从染色体长度观察,除了香酸野苹果和长柄红霞果以外,其他的类型均含有不同数目的长染色体(L)、中长染色体(M2)、中短染色体(M1)以及短染色体(s)等4种类型,没有发现随体。(2)染色体结构特征方面,新疆野苹果24个种下类型染色体的平均臂比为1.27-1.56,核型不对称系数为56.01%-63.39%。核型类型大部分为1A和1B型,也有个别的2A和2B;1A、1B、2A、2B所占的比例分别为41.67%、37.5%、8.33%和12.50%。(3)进化趋势图显示,黄圆野苹果最为特殊,其核型不对称系数最高(63.39%),其进化程度最高,其次是霍城圆果野苹果和清香野苹果,小花野苹果的进化程度最低(56.01%);其余20个种下类型进化趋势具有较高的一致性,趋势较为集中;其中,大扁心野苹果的进化程度最低。(4)聚类分析显示,24个种下类型分为3类,第一类包括9个种下类型,它们具有较高的核型特征相似性,大多数类型的平均臂比大于其他类型,结合进化趋势结果,发现它们的进化趋势比别的类群较高;第二类包括11个,核型类型大多数为1B、2A、2B;第三类4个类型,它们的平均臂比和核型不对称系数最小,核型类型属于1A和1B,说明这类群的遗传相对稳定。【结论】新疆野苹果24个种下类型的核型特征有一定差异,根据核型特征,可以对其进行分类;与传统分类方法比较,其揭示的种下类型之间的亲缘关系更加明晰,聚类结果更能反映出类型之间的一致性与差异性。结合核型特征可初步判断种下类型的进化趋势,这对进一步研究新疆野苹果种下类型的系统进化有重要参考作用。 相似文献