淡黄花百合根尖染色体C-带分析

利用Giemsa C-带方法对淡黄花百合(Lilium sulphuFeum Baker)进行了研究.结果表明:淡黄花百合(Lilium sulphureum)的染色体数目为2n=2x=24,每条染色体上都显示出特征带,带纹的深浅差异明显,其带 .型公式为:2n=24:2CI+2I+4CI++2CI++8I++2I+T++2IT++2I+N.染色体F有两条强弱不同的中间带和一条次缢痕带.通过Cdemsa C-带方法可以将淡黄花百合(Lilium sulphureum Baker)的每条染色体区分开.     

三个卷瓣组百合的根尖染色体C-带比较

利用染色体组型分析进行种和种质资源的识别是一种有效的手段.本文利用Gemisa C-分带方法对三个卷班组百合南川百合(L.rosthornii)、川百合(L.davidii)和金佛山百合(L.jinfushanense)根尖染色体进行了研究.南川百合的带型公式为:2n=24=10C 8CI 2I 2N 2,川百合的带型公式为:2n=24=4C 2CI 2I 6I 2I 2I T 2T 2CNT 2,金佛山百合的带型公式为:2n=24=4C 4CI 4CI 4L 2I 2I 2I T 2.通过GemisaC-分带方法不但可以很好的区分各种的各条染色体,而且可以很好的区分这三个卷瓣组野生百合.     

百合染色体细胞学研究进展

百合属绝大多数种是2n=24的二倍体,其核型具有稳定性,一般为3B型,存在少数多倍化现象,但广泛存在B染色体,百合染色体核型的差异正是环境因素和结构变异共同作用的结果。通过百合属C-带带型中单套染色体条带数及特征染色体可以清晰地区分形态学相似的百合属植物,但采用尿素法进行G带带纹的鉴定有更高的分辨率。原位杂交技术已运用于百合属植物的区分和杂种后代的鉴定,而GISH较FISH更适用于杂种百合的鉴定。     

杉木根尖细胞染色体C带及荧光带型的研究

对杉木的根尖有丝分裂中期染色体进行研究,结果发现,杉木的染色体核型为2n=22=20m(2SAT) 2sm,10对染色体均为中间着丝粒染色体,只有1对(最小一对)为近中着丝粒染色体,第3对为具随体的染色体,核型不对称性属于1B型.对杉木的Giemsa C-带进行研究发现,有8对染色体有C带出现,只有3对染色体无C带,C带纹均出现在染色体的两臂.且利用C带在杉木11对染色体上的分布情况,能够较容易地辨认出11对中的5对染色体.而荧光分带研究的结果则为在杉木根尖细胞的中期分裂相中,只有CMA(色霉素A3)在带有随体的染色体的次缢痕和随体处有专一的荧光带纹,而DAPI无带.CMA带比DAPI带更适宜杉木的分带研究.最后讨论了C带与荧光带的在杉木染色体研究中的应用.     

二倍体野燕麦染色体的C-带分析

采用C-带技术对二倍体野燕麦根尖细胞染色体进行了带型分析,以研究该野燕麦染色体的C-带特点.结果表明:二倍体野燕麦具有7对染色体,其上共有35条带,其中长臂具有带纹19条,包括13条中间带(I),6条末端带(T);短臂具有8条带纹,包括2条中间带(I),6条末端带(T),另外还有l条随体带(S)以及7条着丝点带(C),其带型公式为2 n=14=2CIT+ +2 CIT+8 CI+ T+2 CI+ T+S.二倍体野燕麦染色体组成为CC,核型为2A,属于较对称核型,进化指数为7.     

提莫菲维小麦染色体的C-带分析

对提莫菲维小麦的根尖细胞染色体进行C-带分析,以明确提莫菲维小麦的染色体C-带带型特点。结果表明:提莫菲维小麦具有14对染色体,其染色体带型公式为:2 n=28=4 IT++4 IT++6 CIT++6 I+2 IT+2 CI+2 CIT+S+2 CIS,共包括98条带,其中长臂具有57条带纹,包括50条中间带(I),7条端带(T);短臂具有35条带纹,包括30条中间带(I),3条端带(T),2条随体带(S);另外还有着丝点带(C)6条。提莫菲维小麦G组染色体的异质化程度明显高于A组染色体,G组染色体的C-带带型与普通小麦B组染色体非常相似,因此G组染色体可能与B组染色体存在部分同源性。     

二倍体栽培棉45 S rDNA-FISH作图及核型比较

以45SrDNA为探针,获得了草棉体、亚洲棉体细胞染色体的荧光原位杂交(FISH)资料。从rDNA FISH实验结果看,草棉有6个杂交信号,也显示了3对核仁组织区(NOR),分别位于第3、9、13对同源染色体上;亚洲棉有4个杂交信号,显示了2对NOR,分别位于第6、13对同源染色体上。草棉、亚洲棉基于45SrDAN FISH的核型分别为:2n=2x=26=20m(4sat) 6sm(2sat)和2n=2x=26=26m(4sat)。     

一个普通小麦-大赖草易位系T01的选育与鉴定

将抗赤霉病的普通小麦-大赖草Lr.2染色体单体异附加系花粉经过60Co-γ射线处理, 然后给感赤霉病的普通小麦品种“扬麦5号”授粉, 杂交后代连续2年进行赤霉病抗性单株接种鉴定, 从中选育出一个普通小麦-大赖草异易位系。 经过染色体荧光原位杂交和Giemsa C-分带鉴定, 易位发生在普通小麦4B染色体长臂和大赖草第2条染色体(L     

一个普通小麦-大赖草易位系T01的选育与鉴定

将抗赤霉病的普通小麦-大赖草Lr.2染色体单体异附加系花粉经过60Co-γ射线处理, 然后给感赤霉病的普通小麦品种“扬麦5号”授粉, 杂交后代连续2年进行赤霉病抗性单株接种鉴定, 从中选育出一个普通小麦-大赖草异易位系。 经过染色体荧光原位杂交和Giemsa C-分带鉴定, 易位发生在普通小麦4B染色体长臂和大赖草第2条染色体(L     

花生的荧光显带和rDNA荧光原位杂交核型分析

建立花生准确而详细的核型对于阐明其起源和开展其基因组研究十分重要。本研究采用DAPI显带和5S、45S rDNA探针双色荧光原位杂交对花生有丝分裂中期染色体进行了分析。结果表明,花生的单倍基因组总长度为(81.06±3.74) μm,最长染色体为(4.72±0.15) μm,最短染色体为(2.62±0.14)μm;有15对染色体显示了着丝粒区DAPI⁺带,其中10对为强带,5对为弱带;有2对5S rDNA位点和5对45S rDNA位点,其中1对5S与1对45S位点同线。综合染色体测量数据、DAPI⁺带和rDNA杂交信号,对花生染色体进行了准确配对和排列,建立了详细的分子细胞遗传学核型。花生的核型公式为2n=4x=40=38m+2sm(SAT),核型不对称类型属于2A型。     

45S rDNA基因在新麦草染色体上的分布

分析rDNA基因位点在染色体上的分布可以对新麦草染色体进行识别和分析其基因组特征。利用FISH和顺序C-分带-FISH技术将45S rDNA定位于新麦草细胞分裂中期染色体上,结果表明,45S rDNA在二倍体新麦草染色体上有6个主要分布位点,另外几条染色体在两臂中部或长臂末端还显示出较弱的杂交信号,信号强度显示蒙农4号新麦草基因组具有一定杂合性。分析确定新麦草的45S rDNA基因主位点分别位于N1染色体短臂末端、N3染色体短臂末端以及N5染色体短臂末端,推测这3对染色体是NOR染色体。     

Molecular cytogenetic characterization and SSR marker analysis of a leaf rust resistant wheat line carrying a 6G(6B) substitution from <Emphasis Type="Italic">Triticum timopheevii</Emphasis> (Zhuk.)

A disease (powdery mildew, leaf rust) resistant line was selected from the progenies of a Triticum aestivum × Triticum timopheevii amphiploid produced at Martonvásár. This line was previously identified with C-banding as a 6G(6B) substitution. In order to detect the 6G chromosome in a wheat background, fluorescence in situ hybridization (FISH) and microsatellite marker analysis were used. Ten microsatellite markers of the 43 tested generated PCR products that were polymorphic between chromosomes 6B and 6G, and four showed length-polymorphism. The FISH hybridization pattern of 6G from T. timopheevii was identified using a combination of four repetitive DNA probes (Afa-family, pSc119.2, pTa71, (GAA)₇). Genomic in situ hybridization (GISH) technique, capable of labelling the A^t and G genomes separately, was used on the same slides to differentiate the A^t and G genomes in T. timopheevii. The A^t and G genomes of T. timopheevii were grouped on the basis of the GISH patterns and a cyclic intergenomic translocation involving 6A^t-1G-4G was detected in T. timopheevii accession TRI667. The presence of 6G in the substitution line was demonstrated using FISH with the four repetitive DNA probes. Chromosome 6G was clearly identified and its FISH pattern was different from that of 6B in the parental wheat cultivar Fleischmann-481. According to field tests, the 6G(6B) substitution line has resistance to leaf rust.     

河南紫斑牡丹的细胞学研究

本文研究了河南紫斑牡丹的核型、Ag-NORs和Giemsa C带带型.核型为2n=2x=10=6m+2sm+2st;C带所显示的端(T)带和Ag-NORs的数目和位置相同.作者认为,紫斑牡丹染色体的T带,实际上应为N带(NOR带);常规染色显示的所谓随体,实际上是端部NORs.     

小麦-中间偃麦草部分双二倍体"中5"的外源染色体的鉴定

应用染色体分带（Ｃ－带）分子原位杂交技术对普通小麦－中间偃麦草（Ｔｈｉｎｏｐｙｒｍｉｎｔｅｒｍｅｄｉｕｍ２ｎ＝４２）Ｅ１Ｅ１Ｅ２Ｅ２ＸＸ）部分双二倍体“中５”（２ｎ＝５６）的外部染色体进行了鉴定分析,染色体分带结果表明：“中５”的７中间偃麦草当色体不显带或显示出与受体小麦亲本染色体相似的带型,单靠型很难准确地鉴定出这７对外源染色体,分带处理后进行人子原位杂交鉴定出“中５”的７对外源染色体,并发现共     

利用原位杂交及CAPS标记分析芸薹属A、B和C基因组间的关系

以来源于Brassica rapa基因组(AA)的重复序列(151 bp)为探针, 分别同二倍体白菜型油菜(AA, 2n=20)、甘蓝(CC, 2n=18)和异源四倍体芥菜型油菜(AABB, 2n=36)的中期染色体杂交, 白菜型油菜和甘蓝的所有染色体上都有杂交信号, 芥菜型油菜的染色体上显示出20个明显的信号, 其余染色体上信号很弱或无, 可以区分出A和B基因组。对来源于油菜3个基本种与3个复合种FAE1基因进行CAPS分析表明, 3个基本种表现出不同的酶切式样, 用Mbo I和Msp I酶切表现出多态性, 基因组A和C非常相似, 而基因组B与A、C关系较远, 同时3个复合种也并不是2个基本种的简单相加, 表明异源四倍体在长期进化过程中可能发生了重排和重组。     

小麦-黑麦代换系间、代换系与易位系间杂交后代染色体易位系的选育

为了选育有经济价值的易位系,探讨小麦-黑麦间产生易位的频率,本研究以小麦-黑麦代换系DS5R/5A和DS6R/6A为母本,以小麦-黑麦易位系克珍(Kezhen)和带有杀配子染色体的代换系DSGC1为父本,分别进行田间杂交。结果表明:DS5R/5A、DS6R/6A与DSGC1(2S)杂交结实率低,平均为27.7%,与克珍(T3B.3R)杂交结实率高于前者,平均结实率为59.3%,二者均好于远缘杂交的结实率,这也表明带有杀配子染色体的亲本影响结实率;对选出的54株DS5R/5A×DSGC1、DS6R/6A×DSGC1杂种后代与80株DS5R/5A×克珍、DS6R/6A×克珍杂种后代进行C-分带、原位杂交和分子标记鉴定后发现,二者的易位频率分别为11.1%和8.8%,并且多为染色体端部小片段易位,这种小片段易位可能是代换系间杂交部分同源染色体交换产生的。此外,也表明杀配子染色体在引起染色体断裂后可发生染色体易位。本研究共获得T5RL.5AS、T5RS.5DL、T5RS.5BL、T6RL.6DS、6RL.6BS以及T6RS.6BL等13个易位系,平均易位频率为9.6%。     

Metaphase-I analysis of a Triticum aestivum x T. monococcum hybrid by the C-banding technique

Summary The meiotic pairing behaviour at metaphase I of a Triticum aestivum×Triticum monococcum hybrid has been studied by means of the C-banding technique to ascertain the homology between the chromosomes in the A genome of the two species. The technique allowed the A and B genome chromosomes and the 2D, 3D and 5D chromosomes to be identified. Differences in the level of chromosome pairing in the A genome were noted. The T. monococcum 4A chromosome did not pair with any of the T. aestivum chromosomes in any of the metaphase I cells analysed. Two reciprocal translocations between the 2B and 2D chromosomes on one side and the 2A and 3D on the other side have been identified. The usefulness of the C-banding technique in the study of chromosome homology among species related to wheat is discussed.     

Fluorescence in situ hybridization polymorphism using two repetitive DNA clones in different cultivars of wheat

Twenty‐two wheat cultivars and a wheat line were analysed with two‐colour fluorescence in situ hybridization (FISH) using the pSc119.2 and pAs1 repetitive DNA clones to detect if polymorphism could be observed in the hybridization patterns of different wheat cultivars. The FISH hybridization pattern of ‘Chinese Spring’ was compared with wheat cultivars of different origins. Differences were observed in the hybridization patterns of chromosomes 4A, 5A, 1B, 2B, 3B, 5B, 6B, 7B, 1D, 2D, 3D and 4D. Although a low level of polymorphism exists in the FISH pattern of different wheat cultivars, it is possible to identify 17 pairs of chromosomes according to their hybridization patterns with these two probes. This study will help to predict the expected variation in the FISH pattern when analysing wheat genetic stocks of different origin. It is presumed that variation in hybridization patterns are caused by chromosome structural rearrangements and by differences in the amount and location of repetitive sequences in the cultivars analysed.     

A new secondary reciprocal translocation discovered in Chinese wheat

A new wheat-rye secondary reciprocal translocation involving T1RS·7DL and T7DS·1BL was detected by chromosome C-banding and genomic in situ hybridization (GISH). The meiotic configuration analysis combined with C-banding and GISH on F₁ hybrids of this newly discovered translocation with T1RS·1BL and Chinese Spring Dt7DS indicated that the new translocation probably resulted from a secondary reciprocal translocation between the primary translocation T1RS·1BL and 7D in the progenies of Aifeng3//Mengxian201/Neuzucht. On the basis of the cytological analysis of progenies and recombinant inbred lines (RILs) (derived from a cross between T1RS·7DL, T7DS·1BL and T1RS·1BL), the translocation chromosomes T1RS·7DL and T7DS·1BL transmitted readily, and appeared in most of the progenies.     

Analysis of stability for some characters in Kabuli Chickpea

Summary The meiotic behaviour of a hybrid between Triticum aestivum and the amphiploid Hordeum chilense x T. turgidum conv. durum, was studied using a C-banding staining method. This hybrid has the genome formula of AA BB D Hch with 2n=6x=42 chromosomes. The durum wheat chromosomes (genomes A and B) were easily recognized, whereas the D and Hch chromosomes were recognized as a whole. Meiotic pairing was homologous, as expected (14 bivalents from A and B genomes +14 univalents from D and Hch genomes). However, some pollen mother cells at metaphase-I presented pseudobivalents that could have been caused by either homoeologous or autosyndetic pairing amongst D and Hch chromosomes.