普通小麦与沙生冰草、根茎冰草属间杂种的产生及其细胞遗传学研究

 通过幼胚拯救，首次获得了普通小麦与沙生冰草、根茎冰草两组合的属间杂种。在幼胚拯救时发现，无盾片的幼胚是不能产生杂种苗的。对获得的两组合杂种植株进行了壮苗和破蘖培养繁苗，使来自同一胚的杂种植株数目增加。在获得的F#-1杂种中，幼苗形态和穗型似普通小麦栽培种。在花粉母细胞减数分裂中期Ⅰ，中国春×沙生冰草、根茎冰草两组合杂种F#-1的染色体配对频率远远超出了期望值。对杂种F#-1用四倍体和六倍体小麦回交，都能很容易获得种子，平均结实率都在15%以上。特别值得注意的是两组合的属间杂种均具有自交可育性，自交结实率分别为0.46%和0.15%。文章讨论了：⒈杂交成功的经验；⒉P与A、B、D染色体组间特殊遗传关系的理论分析；⒊F#-1自交结实的原因；⒋壮苗培养和破蘖培养繁苗在小麦远缘杂交中的重要作用。小麦属与冰草属间自交和回交后代的首次获得，在理论上对前人所认为的P染色体组在小麦族中的高度独立遗传性，提供了直接的相反证据；在实践上，使产生异源附加系、代换系甚至易位系、进而为利用P染色体组中的期望基因变得相对的容易。     

三种鹅鸡草的生物系统学研究

通过对鹅观草属犬草组长芒鹅观草、缘毛鹅观和鹅观草３个种及春种间杂种的形态变异、染色体配对行为和繁育特性进行研究,探讨这３个种的亲缘关系。Ｆ１植株的外形趋于两亲本之间。在减数分裂过程中,亲本种染色体配对正常。杂种Ｆ１的染色体配对数较高,平均构型：Ｒ．ｐｅｎｄｕｌｉｎａ＊Ｒ．ｄｏｌｉｃｈａｔｈｅｒａ为０．５６１Ⅰ＋１３．７２Ⅱ;Ｒ．ｄｏｌｉｃｈａｔｈｅｒａ＊Ｒ．ｋａｍｏｊｉ为７．５８Ⅰ＋１３．５８Ⅱ＋     

A synthetic hexaploid (2n = 42) oat from the cross of Avena strigosa (2n = 14) and domesticated A. magna (2n = 28)

A synthetic hexaploid oat was produced by chromosome doubling of a sterile triploid hybrid between cultivated Avena strigosa (2n = 14) cv. Saia and a domesticated form of A. magna (2n = 28). The synthetic hexaploid was intermediate between its parents in panicle shape and lemma color, similar to the tetraploid parent in spikelet structure, and to the diploid parent in having a single, albeit partially shriveled seed per spikelet, and low protein content. By the third generation, plants with yellowish lemmas, mostly two seeds per spikelet and better filled grains had been selected. Rust resistance of the diploid parent was retained in the synthetic hexaploid, but not tolerance to barley yellow dwarf virus disease (BYDV). Chromosome associations at meiosis in the triploid hybrid was low, with over 60% of them being univalents. Bivalent association was the rule in the synthetic hexaploid with an occasional one or two quadrivalents. Regular meiosis with 21 bivalents was observed in further generations. The preferential pairing of homologous chromosomes in the synthetic hexaploid was probably contributed by the A. strigosa genome which exhibits this tendency in artificial allopolyploid situations. Selection of yellow lemma color and two seeds per spikelet suggests that the genes controlling these traits are located on the chromosomes involved in quadrivalents in the synthetic hexaploid. The potential and limitations of utilizing the synthetic hexaploid in oat research and breeding are briefly discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Transfer of Thinopyrum-Derived Leaf-rust Resistance from Common Wheat to Durum Wheat.

The leaf rust resistance gene on chromosome 7AL of ‘Chinese Spring’ transfer no. 12 derived from Thinopyrum ponticum, was transferred to durum wheat by standard backcrossing. In ‘Agatha’ and ‘Indis’ a leaf rust resistance gene from Thinopyrum ponticum and Thinopyrum ponticum respectively, is found on a translocated segment on chromosome arm 7DL. The use of the ‘Langdon’ disomic D-chromosome substitution lines for 7A and 7B resulted in the recovery of tetraploid leaf-rust resistant lines from the crosses with ‘Agatha’ in the B₂F₁ generation. Tetraploid lines carrying the ‘Indis’ translocation segment were recovered in the B₂F₂ generation. The F₂ segregation ratios for rust resistance after selfing or back-crossing generally fitted a 1: 1 ratio indicating non-transmission of the translocation segments in the male gametes. Homozygous resistant plants were not obtained. Meiotic instability was observed in 28 chromosome B₂ F₂ derivatives of the crosses between ‘Chinese Spring’ transfer no. 12 and durum wheat.     

小麦PH基因系的研究及应用

小麦中存在着抑制部分同源染色体配对的两个主效基因ＰＨ１和ＰＨ２。此外,还携带有许多微效的抑制或促进配对基因。小麦染色体配对过程是受一个多基因系统控制,相当复杂。ＰＨ基因制约减数分裂前当染色体的联会。     

普通小麦与黑麦的杂交亲和性及其杂种F_1染色体配对行为的研究

以普通小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ２ｎ＝６ｘ＝４２）为母本和奥地利黑麦（Ｓｅｃａｌｅｃｅｒｅａｌｅ,２ｎ＝２ｘ＝１４）杂交,对其杂交亲和性和杂种Ｆ１的染色体配对行为进行了观察,结果表明,供试２２个品种的杂交亲和性存在明显差异,４个品种的杂交结实率大于５０％,其可能基因型为ｋｒ１ｋｒ１ｋｒ２ｋｒ２,４个品种的杂交结实率介于３０％～５０％之间,其基因型可能为ｋｒ１ｋｒ１Ｋｒ２Ｋｒ２,４个品种的杂交结实率介于１０％～３０％之间Ｋｒ１Ｋｒ１ｋｒ２ｋｒ２,７个品种杂交结实率小于５％;基因型可能为Ｋｒ１Ｋｒ１Ｋｒ２Ｋｒ２;杂种Ｆ１ＰＭＣ的染色体配对能力与亲本杂交亲和性无明显相关,相关系数为０．０１２１,但不同组合存在一定差异,８６４１０１２／黑麦Ｆ１具有最好的配对能力（平均交叉结数＝１．３）,而碧蚂４号／黑麦等具有较差的配对能力（平均交叉结数为０）,其它品种（系）介于二者之间。８６４１０１２是具有较好亲和性和较高Ｆ１ＰＭＣ染色体配对水平的综合性状优良的小麦品系,可进一步用于小麦的远缘杂交以转移外源遗传物质。     

飞行控制系统的动态相对增益方法研究

提出一种分析多变量飞行控制系统的动态相对增益方法。从基于时间和基于频率两个方面分别计算了飞行器线性化模型的动态相对增益,通过基于时间的动态相对增益可以得到动态模型在其时间范围内输入量和输出量的关联度,而不是局限于最终稳态点的关联度,通过对一定工作频率范围的基于频率动态相对增益的求取,可对输入/输出量进行合理的配对,以便来分析和设计具有合适的频率特性的飞行控制系统。通过实例求解表明,两种方法所得配对结果一致,将时域和频域方法结合可以得到全面的分析结果。     

Development and Molecular Characterization of Wheat-Aegilops peregrina Introgression Lines with Resistance to Leaf Rust and Stripe Rust

A wild non-progenitor species from wheat (Triticum aestivum L.) tertiary gene pool, Aegilops peregrina (Hack.) Maire & Weiller accession pau3519 (UUSS), was used for introgression of leaf rust (caused by Puccinia triticina) and stripe rust (caused by Puccinia striiformis f. sp. tritici) resistance in bread wheat. The accession was crossed and backcrossed with hexaploid wheat line Chinese Spring Ph^I to develop two homozygous BC₂F₆ wheat-Ae. peregrina introgression lines (ILs), viz., IL pau16058 and IL pau16061, through induced homoeologous recombination. Homozygous lines were screened against six Puccinia triticina and two Puccinia striiformis f. sp. tritici pathotypes at the seedling stage and a mixture of prevalent pathotypes of both species at the adult plant stage. IL pau16061 showed resistance to leaf rust only, whereas IL pau16058 was resistant to both leaf and stripe rust pathotypes throughout plant life. Molecular profiling of these ILs with simple sequence repeat (SSR) markers indicated that alien introgressions were mainly terminal and very few were interstitial. Identification of linked markers with advanced genomic technologies will aid in marker-assisted pyramiding of alien genes in cultivated wheat background.     

Cytogenetic studies of the interspecific hybrids between Hystrix longearistata in Japan and Hystrix duthiei in China

Cytogenetic studies of Hystrix duthiei (2n=28) from China, Hystrix longearistata (2n=28) from Japan and their artificial hybrids were carried out. The F1 hybrids showed a very high degree of bivalent pairing at the meiotic Metaphase-I. No multivalents were found. Partial fertility of the hybrids was observed. The results indicated that they shared two highly homologous genomes and were closely related.     

两个鹅观草与披碱草属间杂种的染色体配对分析

通过人工远缘杂交,成功获得老芒麦(Elymus sibiricusL.,2n=4x=28)与大鹅观草(Roegneria grandisKeng,2n=4x=28)及鹅观草(R.kamojiOhwi,2n=6x=42)与Wawawai披碱草(E.wawawaiensisJ.R.Carlson&Barkworth,2n=4x=28)属间杂种F1植株。分析杂种减数分裂染色体配对行为显示:E.sibiricus×R.grandis染色体配对构型为17.90Ⅰ+4.90Ⅱ+0.10Ⅲ;R.kamoji×E.wawawaiensis的构型为11.02Ⅰ+11.96Ⅱ+0.02Ⅲ。结果表明:老芒麦与大鹅观草存在一个染色体组的部分同源关系(St),鹅观草与Wawawai披碱草具有2对同源的染色体组(St和H)。本试验结果与前人细胞学报道一致,支持大鹅观草具有StY染色体组。鹅观草属与披碱草属具有不同的染色体组组成,应为两个独立的属。