【作者】 王睿辉；

【导师】 李立会；

【作者基本信息】 中国农业科学院 ， 作物遗传育种， 2004， 博士

【摘要】 本研究通过形态学、细胞学、分子生物学方法及田间抗病性鉴定,对20个小麦-冰草二体附加系开放授粉后代的细胞学稳定性、形态学、条锈病和白粉病抗性以及冰草染色体与小麦染色体之间的部分同源关系进行了分析。 在所检测的20个小麦-冰草异源二体附加系后代中,细胞学稳定性存在较大的差异。在10个材料中检测到2n=44植株,平均频率为74.78%,变异范围在33.3%～100%。在10个材料的后代植株中,其染色体组成主要以2n=42为主,没有检测到2n=44的植株。通过GISH分析,在这些后代中检测到1个代换系5111-1和1个易位系5112-4。这一结果表明,冰草P基因组能够较为容易地与小麦A、B、D基因组发生易位,从而将冰草的优异基因转移进普通小麦。因此,加强对附加系后代的检测,有助于从中选出携带冰草优异基因的代换系或易位系材料。 根据形态学和农艺性状调查,将其中10个2n=44植株占不同比例的材料归为5类。Ⅱ-4-2、Ⅱ-5-1、5038,Ⅱ-21-2、Ⅱ-21-6,Ⅱ-9-3、Ⅱ-11-1,Ⅱ-29-2(ⅱ)、Ⅱ-30-5,等9个附加系可分别归作4类,Ⅱ-8-1(ⅰ)单独归为一类。每一类都有其自身的典型特征。2n=42为主的材料较之2n=44,表现出茎秆较粗,穗子较长,株高较高,穗下茎节较长等特点。在籽粒颜色上,二者也表现出明显的不同。 用小麦的SSR引物对10个小麦-冰草二体附加系及其亲本Z559、Fukuho的扩增结果表明,小麦的SSR引物可以从冰草的基因组DNA中扩增出多态性的标记:在101对多态性SSR引物中,有24对引物可以在附加系中扩增出冰草特异的片段。从每个部分同源群各选择1个SSR标记,可以初步建立起不同附加系中冰草染色体与小麦染色体间的部分同源关系。同时发现,随着SSR标记数量的增加,可以揭示出冰草P基因组在遗传演化中所发生的复杂变化,以及冰草P基因组与普通小麦A、B、D基因组关系的复杂性。 在受鉴定的20个小麦-冰草二体附加系和4份附加系衍生材料中,有3份附加系材料表现条锈病抗性,4份附加系材料表现白粉病抗性,2个附加系的4份衍生系都至少表达了对其中一种病害的抗性反应。 结合对附加系Ⅱ-21-2、Ⅱ-21-6的比较分析,认为附加系亲本之一的四倍体冰草的2个P基因组之间可能存在一定的遗传分化,这种分化不仅导致了Ⅱ-21-2与Ⅱ-21-6在细胞学上的差异,也可能与小麦-冰草二体附加系数目多于理论值相关联。Ⅱ-21-2中较高频率出现的多价体表明,该附加系中的冰草染色体可能是影响到小麦染色体联会的原因。更多还原

【Abstract】 Morphological, cytological, molecular methods and pathological screening were employed to analyze the cytological stability, agronomic characters and homoeologous relationship between bread wheat and wheatgrass (Agropyron cristaum) (2n=4x=28) chromosome of 20 wheat-A. cristaum chromosome disomic addition lines.Among the 20 addition lines analyzed, great variations of cytological stabilities existed. Plants with chromosome constitution of 2n=44 varied greatly between open-pollinated progenies of 10 wheat-A. cristaum addition lines, ranging from 33.3% to 100%, with average 74.78%. In the remaining 10 addition lines, no plants with 2n=44 were observed while the plants with 2n=42 predominated. However, GISH analysis for progenies with 2n=42 of 4 disomic addition lines showed that one translocation line and one substitution line between A. cristatum and wheat chromosomes were recovered. It is suggested that translocation or substitution between A. cristatum and wheat chromosomes occurred readily. Therefore, strengthening detection for the alien chromatin in the progenies of disomic addition lines can be helpful for the recovery of translocation or substitution lines with desirable genes from A. cristatum genome.According to the similarities of morphological and agronomic characters, ten disomic addition lines can be divided into five groups, with which each group has its typical characteristics. For the progenies with chromosomal constitution of 2n=42, they displayed thicker stems, longer spikes, taller height and longer internode length underneath spike than those of the counterpart plants with 2n=44. Obvious difference of seed color was observed on the two types of plants with different chromosomal constitutions.SSR results showed that SSR primer sets from wheat (Triticum aestivum) and Aegilops tauschii, can amplified A.cristatum chromosome-specific bands from A. cristaum genome. Among 101 polymorphic primers between Fukuho and Z559, which are the wheat and A. cristatum parents respectively, 24 primer sets can amplify wheatgrass-specific bands from the wheat-A. cristatum disomic addition lines. With one SSR marker from each homoelogous group, the homoeologous relationship between wheat and A. cristatum chromosomes can be established readily. However, with the increasing of SSR markers, such homoeologous relationship displayed complicated tendency. This may imply structurally intricate changes occurring during the evolution of P genome in A. cristatum.From the 24 lines derived from progenies of wheat and A. cristatum cross, several lines were identified as resistant lines to either wheat powdery mildew or yellow rust pathogen isolates. Three and four disomic addition lines displayed resistant to powdery mildew and yellow rust, respectively. Four derivatives from two addition lines were screened as resistant lines to the both pathogens above-mentioned.Cytological analysis combined with molecular analysis on the lines of II-21-2 and II-21-6,更多还原