节节麦与普通小麦杂交后代的遗传多样性分析

运用SSR标记的方法,对节节麦SQ-214与普通小麦杂交后代的BC1F2群体的64份材料和高代系群体的147份材料在D基因组上的68个SSR位点的遗传多样性进行了分析.结果表明:68对SSR引物在杂交后代的两个群体等位变异位点较多,BC1F2群体共检测到67个位点有变异,等位变异数为212个,主要集中在3D染色体上.高代系中58个位点有变异,等位变异数为184个,等位变异位点多集中在2D上.BC1F2和高代系群体在D基因组的7条染色体上遗传多样性的表现不一致,BC1F2在7条染色体上的遗传多样性显著高于高代系,等位变异分布较高代系均衡.BC1F2材料间的遗传多样性高于高代系.由此可知,节节麦与普通小麦杂交衍生后代具有较高的遗传多样性,可用于进一步改良小麦;同一衍生亲本的衍生后代具有较大的遗传分化,尤其是在随机群体;经过选择后的群体遗传多样性会明显的降低.     

STUDY ON D GENOME OF TRITICUMAESTIVUM SSP. YUNNANENSE KING

<正> Two accessions of Aegilops tauschii Cosson. one collected from the Middle East and the other from Henan Province of China. were crossed with Triticum aestivum ssp. yunnanense King. Chromosome pairings were analysed at metaphase Ⅰ. Meiotic configurations of the hybrids were 14.14Ⅰ+5.32 ring Ⅱ+1.52 rod Ⅱ for the Middle East Ae. tauschii x T. aestivum ssp. yunanense; 14.06Ⅰ+5.29 ring Ⅱ+1.69 rod Ⅱ for Henan Ae. tauschii x T. aestivum ssp. yunnanense. The frequencies of cells which had 7Ⅱ+14Ⅰconfiguration were 87.04％ and 97.05％ for the Middle East Ae. tanschii x T. aestivum ssp. yunnanense and Henan Ae. tauschii x T. asetivum ssp. yunnanense. respectively. The results indicated that D genome of T. aestivum ssp. yunnanense is unchanged compared with the D genome donor.     

小麦与钩刺山羊草杂种的育性,抗病性和细胞遗传学研究

钩刺山羊草高抗条锈、叶锈等病害。以钩刺山羊草为母本与小麦品种鲁麦１５杂交,杂交结实率为５５．２６％,利用鲁麦１５作父本与杂种Ｆ１回交结实率为２２．０９％。Ｆ１和Ｆ２的自交结实率分别为１３．８％和８．２５％。细胞学观察结果表明,Ｆ１、Ｆ２和ＢＣ１ＰＭＣ ＭＩ的平均染色体构型分别为２５．３４Ｉ＋４．２３Ⅱ＋０．１２Ⅲ＋０．２１Ⅳ、１８．６２Ｉ＋９．１３Ⅱ＋０．０７Ⅲ＋０．４２Ⅳ和８．５６Ｉ＋１６．８１     

Resistance to wheat leaf rust in Aegilops tauschii Coss. and inheritance of resistance in hexaploid wheat

A collection of 164 Aegilops tauschii accessions, obtained from Gatersleben, Germany, was screened for reaction to leaf rust under controlled greenhouse conditions. We have also evaluated a selection of synthetic hexaploid wheats, produced by hybridizing Ae. tauschii with tetraploid durum wheats, as well as the first and second generation of hybrids between some of these resistant synthetic hexaploid wheats and susceptible Triticum aestivum cultivars. Eighteen (11%) accessions of Ae. tauschii were resistant to leaf rust among which 1 was immune, 13 were highly resistant and 4 were moderately resistant. Six of the synthetic hexaploid wheats expressed a high level of leaf rust resistance while four exhibited either a reduced or complete susceptibility compared to their corresponding diploid parent. This suppression of resistance at the hexaploid level suggests the presence of suppressor genes in the A and/or B genomes of the T. turgidum parent. Inheritance of leaf rust resistance from the intercrosses with susceptible bread wheats revealed that resistance was dominant over susceptibility. Leaf rust resistance from the three synthetics (syn 101, syn 701 and syn 901) was effectively transmitted as a single dominant gene and one synthetic (syn 301) possessed two different dominant genes for resistance.     

普通小麦与粗山羊草正反交育性机理的胚胎学研究

用石蜡切片和塑料切片法,对中国春与粗山羊草正、反交授粉后不同时间固定的子房进行了胚胎学研究.结果表明,虽然正、反交均能受精发育,但两者的受精率和成胚率相差极大.正交组合的平均受精率和成胚率分别为23.75%和4.58%;而反交组合的平均受精率和成胚率分别为87.08%和82.08%.尽管如此,正交所形成的正常胚的质量比反交形成的     

牡山羊草puroindoline a基因的克隆与表达分析

puroindoline a （Pin a）和puroindoline b（Pin b）是控制小麦籽粒硬度的主效基因。根据已报道的小麦Pin a基因的保守序列,设计合成了1对特异性引物ForA1和RevA1,对六倍体牡山羊草Aegilops juvenalis（UUMMDD）的基因组DNA和胚乳cDNA进行Pin a基因扩增、克隆、序列测定和表达分析,发现了1个新型Pin a（Pin a～allele）,其ORF长4／17bp,编码148个氨基酸残基,具有麦类作物Pin a基因特有的28个氨基酸的信号肽序列和WRWWKWWK的色氨酸结构域基因序列,与软粒小麦cv.capilole的Pina—Dla相比较,其核苷酸同源性和氨基酸同源性分别为98．7％与96．6％。Pin a～allele含有1个紧邻色氨酸结构域的突变位点（Gln 77Leu）。RT～PCR证实了Pin a在籽粒胚乳中的表达。Soulhern Blot分析结果表明,牡山羊草中Pin a基因含有1个拷贝。研究结果表明,山羊草中包含着与小麦差异较大的籽粒硬度控制基因。     

QTL Mapping for Important Agronomic Traits in Synthetic Hexaploid Wheat Derived from Aegiliops tauschii ssp. tauschii

Aegiliops tauschii is classified into two subspecies： Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata. Novel genetic variations exist in Ae. tauschii ssp. tauschii that can be utilized in wheat improvement. We synthesized a hexaploid wheat genotype（SHW-L1） by crossing an Ae. tauschii ssp. tauschii accession（AS60） with a tetraploid wheat genotype（AS2255）. A population consisting of 171 F8 recombinant inbred lines was developed from SHW-L1 and Chuanmai 32 to identify QTLs associated with agronomic traits. A new genetic map with high density was constructed and used to detect the QTLs for heading date, kernel width, spike length, spikelet number, and thousand kernel weight. A total of 30 putative QTLs were identified for five investigated traits. Thirteen QTLs were located on D genomes of SHW-L1, six of them showed positive effect on agronomic traits. Chromosome region flanked by wPt-6133–wPt-8134 on 2D carried five environment-independent QTLs. Each QTL accounted for more than 10% phenotypic variance. These QTLs were highly consistent across environments and should be used in wheat breeding.     

节节麦遗传多样性的SSR标记分析

节节麦是普通小麦的供体祖先种,具有丰富的遗传变异和优良性状,可用于拓宽现代小麦的遗传基础。本试验利用22个小麦D染色体组特异微卫星标记,对国内外的85份节节麦材料进行遗传多样性分析,结果共检测出195个等位变异,平均每个标记8.86个。节节麦染色体间平均等位变异顺序为6D>2D>5D>1D>7D>3D>4D;22个标记揭示的多态性信息指数——PIC值,分布在0.3385和0.8129之间,染色体间大小顺序为1D>5D>2D>4D>3D>6D>7D。研究表明,85份节节麦材料遗传多样性较高,为节节麦的有效利用提供了依据。     

偏凸山羊草的抗条锈病新基因YrG775的AFLP标记

对小麦抗病种质贵农775与西农97148的F2后代人工接种CY32条锈病菌,对其进行了抗性鉴定,通过卡方检测抗感病单株分离比例,确定贵农775携带有2对重叠抗条锈病基因。从128个AFLP引物组合中,筛选到与其中1个抗病基因YrG775共分离的多态性标记M8P15(1 200 bp),该标记仅能在原始亲本偏凸山羊草中检测到。由于已知来源于偏凸山羊草的Yr17苗期不抗CY32条锈病菌,所以根据抗性鉴定和分子生物学试验结果,推断YrG775很可能是1个来自偏凸山羊草,并与已知抗条锈病基因都不同的新基因。     

Au Elements and Their Evolution in Some AIIopolyploid Genomes of Aegilops

To study the sequences of short interspersed nuclear elements （SINEs） evolution in some allopolyploid genomes of Aegilops, 108 Au element fragments （a novel kind of plant SINE） were amplified and sequenced in 10 species of Aegilops, which were clustered into three different groups （A, B and C） based on their related geuome types. The sequences of these Au element fragments were heterogouous in di-, tetra-, and hexa-ploids, and the deudrograms of Au element obtained from phylogenetic analysis were very complex in each group and could be clustered into 15, 15 and 22 families, respectively. In this study, three rules about Au elements evolution have been drawn from the results： i. Most families were composed of Au element members with different host species in three groups; ii. Family 1-6 in Group A, Family 1-6 in Group B, Family 1-4 and Family 6-13 in Group C contained only one, apparently highly degenerate Au dement member （a single representative elemeut）; iii. Elements generally fell into clades that were species-specific with respect to their host species. The potential mechanisms of Au element evolution in Aegilops were discussed.