提莫菲维小麦与葡萄牙野燕麦远缘杂交后代的SRAP分析

采用SRAP技术分析提莫菲维小麦与葡萄牙野燕麦远缘杂交后代的真实性及其特点。结果表明,22对SRAP引物中,20对引物在双亲间扩增出多态性条带,其多态性比率为73.81%。me4-em1、me3-em5、me4-em3和me3-em3四对引物在提莫菲维小麦与葡萄牙野燕麦杂交F3株系中扩增出双亲特异带,表明该F3株系具有双亲的遗传物质,该F3株系是提莫菲维小麦和葡萄牙野燕麦成功属间杂交的真实杂种后代。在F3株系的扩增结果中部分双亲带型消失,并且提莫菲维小麦消失的带数远少于野燕麦的;同时有非父母标记新带型出现。杂种后代DNA序列的这种变化可能有利于新形成异源多倍体小麦的快速进化、遗传协调和遗传稳定性。     

提莫菲维胞质普通小麦雄性育性恢复的改良

小麦育种的一项重要任务仍然是培育可行的商用杂交小麦。获得充足的异花授粉的有效方法有赖于胞质雄性不育系(A系)与优良恢复系(R-系)的结合。有70多种雄性不育胞质，能引起普通小麦的雄性不育。其中，提莫菲维(T.tumopheevii)、Aegilop Kotschyi和Ae.ventricosa胞质在小麦杂种优势利用中最为广泛，前者(T-型胞质雄性不育，T-     

蓝粒小麦育种衍生材料染色体的C带检测

本研究应用改良的C-带技术,对供试蓝粒小麦衍生后代11个株系共94个单株进行了分析检测,结果表明:94个单株中有25个单株检测到了长穗偃麦草的4 Ag染色体,导入率为26.60％.本研究结果可为蓝粒小麦育种后代的选育提供理论参考.     

西藏小麦及半野生小麦异染色质分化的C-带研究

以Giemsa C-带技术研究了西藏小麦、西藏半野生小麦和中国春的异染色质分化。它们之间的带型没有很大的差异,但出现了C-带多态性。多态性主要表现在A、B组染色体和分布于染色体臂的中部及端部。以中国春C-带为标准的比较表明,半野生小麦的多态性所属染色体主要为A组的2A、6A和7A,B组的2B、3B、4B和7B,西藏小麦为2A、7A和7B。推测它们同属一个类群,西藏半野生小麦比西藏小麦和中国春原始,并非是来自栽培小麦的杂交后裔。     

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.     

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.     

植物染色体C-显带技术及其在小麦育种中的应用研究进展

本文就染色体C－显带技术及其在小麦近缘种属中的核型分析、亲缘关系和染色体组进化及外源染色质的鉴定等方面国内外研究新近动态做一简述和探讨。     

一粒小麦染色体高分辨显带

AMD 法显带技术对一粒小麦的染色体进行染色体高分辨显带,经过放线菌素 D 预处理、Ohnuki′s 溶液低渗、固定液中捣碎涂片法制片、Wright-Giemsa 染色等显带程序,可以在一粒小麦的所有染色体上成功地显示丰富的高分辨带纹,并对其进行了分析与配对,平均每条染色体上有20多条深带,整个染色体组共显143条带纹。这将对一粒小麦染     

节节麦-黑麦双二倍体的染色体C-带分析

通过对节节麦-黑麦双二倍体及其亲本节节麦、黑麦的C-分带研究,表明节节麦-黑麦双二倍体含有其双亲完整的染色体组,其C-带带型与亲本的C-带带型基本一致,从细胞学水平上证实了该种质是人工合成的一种新的异源多倍体。     

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.     

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.     

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     

Further Studies on the Restoration of Fertility in Triticum durum×T. timopheevi Hybrids

Twenty one F₁ hybrids involving three Triticum durum cultivars and eleven forms of T. timopheevi were backcrossed to their respective durum parents. Backcross fertility (BC₁ grain set) of these sterile hybrids improved with the rise in temperature at the time of pollination. A mean temperature of less than 20 °C results in poor seed set while higher mean temperatures around 24 °C result in increased seed set. It is suggested that a large number of backcross seeds can be produced by pollinating these hybrids late in the season, i.e., after 20th of March in northern India.     

Cytogenetic analysis of a long-term Triticum timopheevii (Zhuk.) Zhuk. cell suspension culture

In vitro culturing of plant cells can cause changes in karyotype. Chromosome variations following long-term propagation in suspension culture of Triticum timopheevii (Zhuk.) Zhuk. were studied by routine staining and C-banding. The culture was highly heterogeneous with respect to the number and structure of chromosomes. The modal class cells had a lower chromosome number than T. timopheevii (2n= 28). This data was confirmed by cytophotometric analysis of nuclear-DNA content. Frequencies of chromosome loss varied for different homoeologous groups. A^t genome chromosomes tended to be preferentially eliminated in cells of different ploidy levels. Deletions, insertions, translocations, telocentric chromosomes, isochromosomes and dicentrics and their derivatives were observed in cultured cells. Chromosomes of various homoeologous groups differed in the frequencies and spectra of re—arrangements, but most aberrations occurred in the G-genome chromosomes. In vitro chromosome modifications did not correspond to in vivo variation. Presumably, this difference was caused by differences in the mechanisms of adaptation to the environment at the levels of the cell and the whole organism. G-genome chromosomes were more frequently involved in this process, both in vivo and in vitro.     

Comparative Analysis of High-Molecular-Weight Glutenin Subunit Composition in Various Triticum Species

Variation in high-molecular-weight glutenin subunit composition amongst Triticum durum cvs. of different origins was investigated by SDS-PAGE and compared with that reported for T. dicoccum and T. aestivum. Tetraploid wheat collections (408 cvs.) were found to carry nearly twice as many Glu-A1 and Glu-B1 alleles as a hexaploid wheat sample of comparable size. In each of the taxa considered, allelic variation at the Glu-B1 locus was markedly greater than that observed for Glu-A1. However, because all the Glu-B1 subunits so far discovered exhibit a restricted and distinctive mobility range during. SDS-PAGE, it is suggested that they are derived from a single source, possibly from Aegilops searsii. Most durum cvs. carried a ‘null’Glu-A1 allele and therefore fewer subunits than dicoccums and common wheats. It is argued that differences in the frequency of occurrence of ‘null’Glu-1 alleles between taxa probably resulted from random samplings made by early agriculturalists and breeders, rather than from an inherent tendency of polyploid wheats to suppress the activity of “redundant” genes.     

Partial asynapsis involving specific chromosomes in intervarietal hybrids of Triticum aestivum L.

Summary Metaphase I chromosome association of the monosomic F1 and the backcross progenies made to develop a monosomic line in the Spanish common wheat Pané-247 was analyzed using a Giemsa C-banding technique. This permits the unequivocal identification of nine meiotic chromosomes (4A, 7A and the seven chromosomes of the B genome). The average frequencies of pairing per arm and of univalents for these nine pairs per arm and of univalents for these nine pairs indicate a difference between arms. The F1 showed asynapsis with univalents in 18.5 per cent of PMC's in intervarietal hybrids. This mainly involved chromosomes 4A, 1B and 6B which also have the largest amount of constitutive heterochromatin. The possible causes of reduced metaphase I association and its rapid decrease during backcrossing are discussed in relation to polymorphism between heterozygous homologous chromosomes.