尾状山羊草与硬粒小麦,普通小麦的杂交及外源染色质检测

尾状山羊草（AegilopscaudataL．）具有丰富的抗病虫和高赖氨酸、高蛋白优良性状,是进行小麦（TriticumaestivumL．）遗传改良的重要遗传资源。合成了硬粒小麦（TriticumdurumDesf．）-尾状山羊草双二倍体、进行了普通小麦与双二倍体的杂交。并以作者克隆的尾状山羊草C基因组特异重复序列PAeca212为探针,对上述杂交后代的花粉母细胞进行了染色体原位杂交检测。证实了新合成的双二倍体中有7对C基因组染色体;在F2中检测到C基因组染色体的自发纯合易位,显示出从C基因组向小麦转移外源基因的光明前景。     

六倍体山羊草与普通小麦杂种F1细胞学研究

粗厚山羊草［Ａｅｇｉｌｏｐｓｃｒａｓｓａ Ｂｏｉｓｓ．（２ｎ＝ ６ｘ＝ ４２,ＤＤＤ２ Ｄ２ＭＣｒＭＣｒ）］、叙利亚山羊草［Ａｅ．ｖａｖｉｌｏｖｉｉ （Ｚｈｕｋ．）Ｃｈｅｎｎ．（２ｎ＝ ６ｘ＝ ４２, ＤＤ ＭＣｒＭＣｒＳＰ ＳＰ）］与普通小麦［Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．（２ｎ＝ ６ｘ＝ ４２, ＡＡＢＢＤＤ）］杂种Ｆ１ 植株形态大多偏向山羊草亲本。４ 个叙利亚山羊草×普通小麦和１ 个粗厚山羊草×普通小麦杂种Ｆ１ 自交结实,结实率在０．１％ —６．５％ 之间。这些种子胚乳很少,生活力较弱,播种后,只有少数种子出苗。杂种Ｆ１ ＰＭＣ减数分裂染色体配对水平较低,出现大量的单价体,二价体低于理论值,并且大多为棒形,说明两种山羊草的Ｄ组染色体已经过很大的修饰。在各杂种Ｆ１ 中还观察到少量的三价体,有些杂种还可见频率很低的四价体和五价体。以山羊草为母本的杂种Ｆ１ 染色体交叉频率优于反交。Ｆ１ 染色体分离极不正常,产生大量的多分孢子和微核。在叙利亚山羊草×冀麦３０ 号中还发现１ 株体细胞染色体为２１ 条的植株,其原因尚需进一步研究确定     

普通小麦与祖山羊草杂种后代的细胞遗传学初步研究

粗山羊草(Aegilops tauschii(Coss.)Schmal.,DD,2n=14)是普通小麦(Triticumaestivum L.,AABBDD,2n=42)D染色体组的供体。粗山羊草中含有丰富的抗病,抗虫,抗逆,优质等优异基因,因此粗山羊草是改良普通小麦的宝贵遗传资源。但有关普通小麦与粗山羊草杂交的研究报道较少。本文试图通过对普通小麦与粗山羊草杂种后代的细胞遗传学和染色体分离规律的研究,探讨转移粗山羊草优异基因的方法和途径。     

粗厚山羊草细胞质对普通小麦遗传效应的初步研究

研究了具有粗厚山羊草（Ａｅｇｉｌｏｐｓｃｒａｓｓａ６ｘ,２ｎ＝６ｘ＝４２,ＤＤＤ２Ｄ２ＭｅｒＭｅｒ）细胞质的普通小麦核质杂种的花粉育性、籽粒蛋白质含量、穗粒数等１０个主要性状的遗传变异,１９９２年～１９９５年连续４年的结果表明：Ａｅ．ｃｒａｓｓａ６ｘ细胞质对普通小麦的产量性状和籽粒蛋白质含量等存在较好的综合效应,对普通小麦的花粉育性、同工酶等性状的表达存在极显著的特异核质嵒プ餍вΑ＃粒澹悖颍幔螅螅幔叮赴试谄胀ㄐ÷蠛酥试又钟攀评煤托坌圆挥档呐嘤确矫婢哂辛肆即蟮那绷Α     

普通小麦远缘杂交F1代表现型研究

小麦远缘杂交试验采用常规杂交方法,不进行胚培养,在自然条件下,实现了普通小麦与小黑麦(6X,AABBRR)、柱穗山羊草(2X,DD)、人工合成六倍体小麦(6X,AABBDD)、CIMMYT人工合成小麦(6X,AABBDD)的杂交.发现在F1代中,出现了2～7种植株表现型、7种性状分离现象;小麦颖壳颜色变化可能受多个加性基因控制;杂交F2代结实率较F1代有数倍或十余倍的增长.     

普通小麦与粗山羊草正,反交的育性研究

普通小麦与粗山羊草杂交需借助幼胚培养方可获得杂种,取授粉１２～１６天的幼胚进行拯拯救,成苗率较高,效果较好。而不同杂交方式对共杂种成胚率、成苗率及思胚拯救率影响很大。以普通小麦为母本,粗山羊草为父杂交时,１５个杂交组合平均杂种成胚率,成苗率及幼胚拯率分别为５．３５％和５８．７３％,而在１２个反交组合中,其平均成胚率,成苗率及幼胚拯救率分别为９８．８８％、１７．１０％和２４．４４％。由此可见,普通小     

普通小麦与粗山羊草属间杂种的染色体构型及其后代的育性特征

利用３个推广品种（莱州９５３、山农辐６３、陕７８５９）分别与原产地不同的抗白粉病的６份粗山羊草［Ａｅｇｉｌｏｐｓｔａｕｓｃｈｉｉ（Ｃｏｓｓ．）Ｓｃｈｍａｌ．］杂交,得到６３个无胚乳的种子,将５６枚幼胚接种到Ｎ６＋０．５ｍｇ／ＬＩＢＡ＋０．２ｍｇ／ＬＮＡＡ的培养基上进行褓姆培养,得到３７个植株。其中莱州９５３与粗山羊草的杂交结实率和成苗率较高,分别平均为８．５８％和４．８２％。粗山羊草对白粉病的抗性     

Hybridization of Aegilops caudata with Triticum durum,Triticum aestivum and the Detection of Alien Chromatins

Aegilops caudata L. carries resistance genes against wheat diseases as well as genes of high crude protein and lysine contents, which can be useful for wheat improvement. An amphiploid of Triticum durum - Ac. caudata was synthesized and the hybridization of T. aestivum with the amphiploid Am 8 was carried out. Chromosome in situ hybridization was carried out for the PMC (pollen mother cell) of the synthesized amphiploid (AABBCC) and ( T. aestivum Beijing 837 × Am 8) F2 by using the pAeca 212 as a probe. The results showed that the 7 bivalents from C genome had hybridization signals in the amphiploid. The detection for F2(Beijing 837× Am 8) indicated that translocation, even (pure) home translocation, occurred in F2 generations spontaneously. The study showed the bright prospect in transferring alien resistance genes from C genome to wheat.     

Cytological Studies on F1 Hybrids Between Hexaploid Aegilops and Triticum aestivum

Morphologcal and cytological studies of hybrids between hexaploid Aegilops crassa Boiss. (2n = 6x = 42, DDD2 D2Mcr Mcr), Ae. vavilovii (Zhuk.) Chen. (2n = 6x = 42, DDMcr McrSp Sp) and Triticum aestivum L. (2n= 6x = 42, AABBDD) were carried out. The results showed that most of the F1 hybrids morphologically resembled their Aegilops parental species. Four Fl hybrids of Ae. vavilovii × T. aestivum and one of Ae. crassa × T. aestivum produced seeds containing few endosperms. The percentage of seed obtained ranged from 0.1% to 6.5 %. These seeds were not vigorous and only a few of them germinated. A large number of univalents appeared at meiosis MI. The frequencies of bivalents were lower than those being theoriticaly estimated. These results indicated that the D genomes in Ae. Crassa and Ae. vavilovii may have been substantially modified. Trivalents were observed in all Fl hybrids. Quadrivalents and pentavalents were also observed in some PMCs during meiosis. The chiasmata frequencies in hybrids using Aegilops species as maternal parents were higher than those in their reciprocal ones. Chromosome segrigations were abnormal at A Ⅰ and A Ⅱ . Polyads and micronuclei appeared frequently at telophase tetrad stage. A plant with 21 chromosomes was obtained in Ae. vavilovii × Jimai 30, although the reason was not yet clear.     

Agronomic Characteristics and Cytogenetic Observation of the Hybrid F1 from Triticum aestivum and Aegilops triuncialis

In order to efficiently introduce the genes of Aegilops triuncialisL. for resistance to powdery mildew into Triticum aestivum L., it is of importance to understand the genetic mechanism of their F 1 hybrid. It was shown that the bivalent frequency was higher than that of the theoretical value. It resulted from the combination of the wheat inhibitors of 5B Ph gene which located respectively on C and U genome of Aegilops triuncialis L. The results of chromosome in situ hybridization with the C genome-specific repetitive sequence, pAeca212, as the probe further indicated that some chromosomes of the C genome of Ae. caudata L. paired with the chromosomes of the other genomes.     

普通小麦与东方旱麦草杂交世代的细胞遗传学研究

对普通小麦（TriticumaestivumL．）与东方旱麦草（Eremopyrumorientale（Ledeb）Jaub．etspach）属间杂种的回交和自交不同世代（BC2F1、BC3F1、BC2F2、BC3F2和BC2F3）进行了细胞遗传学研究。结果表明,BC2F1代（2n＝44）的植株回交产生的BC3F1代分离2n＝43植株的比例较高;为41．09％,2n＝44的植株类型的比例仅为4．11％;从自交后代BC2F2中分离2n=44植株类型的比例较高,为13．21％。回交二代（BC2F1）多数单株花粉母细胞（PMC）减数分裂过程中出现的单价体数较高,且回交结实率和自交结实率分别与该植株平均每PMC中出现的单价体数呈负相关,其相关系数分别为-0．6766和-0．7429。对BC2F3代部分种子进行的基因组原位杂交检测显示,2n＝44的不同植株所含有的外源染色体数目仍有不同。这些结果说明,由于外源染色体的存在,影响了小麦本身同源染色体的正常配对和分离,降低了小麦染色体的遗传稳定性。     

Cytogenetic Studies on the Cross generations Between Triticum aestivum and Eremopyrum orientale

The cytogenetics of the backcross generations and self-bred progenies (BC2F1, BC3F1, BC2F2, BC3F2 and BC2F3) of intergenetic hybrid of Triticum aestivum L. x Eremopyrum orientale (kedeb) Jaub. Et Spach were studied. The results showed that the plants BC3F1 (2n = 43 ) isolated from the backcross generations of the plants (2n = 44 ) accounted for 41.09%, but the plants (2n = 44) isolated was only 4. 11%, and the plants BC2F2 (2n = 44) isolated from self-cross generations of the plants BC2F1 (2n = 44) accounted for 13.21%. The number of univalents in pollen mother cells was higher in some plants (BC2F1) and the averages of univalents were negatively related to the backcross seed-setting and self-cross seed-setting with a related coefficient of － 0.6766* and －0.7429* respectively. The results of genomic in situ hybridization (GISH) showed that some plants of BC2Fs (2n=44) contained different number of alien chromosomes. All those indicated that alien chromosomes caused unusual pairing and segregation of wheat homologous chromosomes and also lowed the hereditary stability of wheat chromosomes.     

A cereal cyst nematode (Heterodera avenae Woll.) resistance gene transferred from Aegilops triuncialis to hexaploid wheat

 The cereal cyst nematode (Heterodera avenae) is an important root parasite of common wheat. A high level of resistance was transferred to wheat from Aegilops triuncialis (TR lines) using the cross [(T. turgidum×Ae. triuncialis)×T. aestivum]. Low fertility (3–5 viable kernels per plant) was observed during the process but the surviving hybrid plants were highly vigorous. To obtain stable resistant lines further crosses to T. aestivum were performed. The resistance in TR lines seems to be transferred from the C genome of Ae. triuncialis (genomes CCUU). Ae. triuncialis was highly resistant to the two Spanish populations of H. avenae tested, as well as to four French races and two Swedish populations. The histological analysis showed a hypersensitive reaction in the roots of a resistant TR line inoculated with the Ha71 pathotype of H. avenae, whereas well-formed syncytia were observed in the roots of the susceptible control. Resistance to the H. avenae Ha71 pathotype seemed to be inherited as determined by a single dominant factor in the crosses between resistant TR lines and susceptible cultivars. Received: 11 November 1997 / Accepted: 9 December 1997     

Hessian fly-resistance gene transferred from chromosome 4Mv of Aegilops ventricosa to Triticum aestivum

 A new Hessian fly (Mayetiola destructor) resistance gene from Aegilops ventricosa and its transfer to hexaploid wheat is described. The 4D(4M^v) substitution line H-93-33 derived from the cross [(Triticum turgidum H-1-1×Aegilops ventricosa no. 11)×Triticum aestivum H-10-15] was highly resistant to the Spanish population tested. Resistance seemed to be inherited as a single dominant factor in the F₂ generation resulting from a cross of H-93-33 with its susceptible parent (H-10-15). Resistance in Ae. venticosa no. 10 was located on chromosome 4M^v using M^v wheat/Ae. ventricosa addition lines. The resistance gene transferred from Ae. ventricosa no. 11 to H-93-33 (H27) is allelic with respect to that of Ae. ventricosa no. 10 and is non-allelic with respect to the genes H3 and H6 from Monon and Caldwell respectively. The assignment of H27 gene to chromosome 4M^v is further supported by its linkage to a gene encoding isozyme Acph-M^v1, previously located on chromosome 4M^v in the line H-93-33. A new marker from homoeologous chromosome group 4 (Amp-M^v2) present in H-93-33 and the 4M^v addition line is described. Received: 12 October 1996 / Accepted: 22 November 1996     

普通小麦和新麦草属间杂种的产生及细胞遗传学研究

进行了普通小麦和华山新麦草属间杂交,运用杂种幼胚培养技术,首次成功地获得了它们的属间杂种。F_1形态趋于中间型,均完全不育。F_1花粉母细胞预期类型(2n=28)的减数分裂中期Ⅰ平均染色体配对构型为26.72Ⅰ+0.62Ⅱ+0.01Ⅲ,后期Ⅰ和后期Ⅱ有落后染色体,多分体具大量微核。结果表明普通小麦和华山新麦草的染色体组间不存在同源或部分同源性。还观察到花粉母细胞异常减数分裂现象。用普通小麦回交,未获得回交后代。     

Molecular Cytogenetic Identification of Triticum aestivum-Secale cereale Substitution and Addition Lines

Two substitution lines, designated as 930498 and 930483, and one addition line, designated as 930029, via Fo immature embryo culture of Triticum aestivum x octoploid triticale ( x Triti-cosecale Wittmack) were identified. Fluorescence in situ hybridization (FISH) using total genomic DNA of rye ( Secale cereale L. ) as probe corroborated the existence of rye chromosomes, further confirmed through chromosome paring at meiotic metaphase 1, C-banding and glutenin SDS- PAGE. The results demonstrated that the two substitution lines are ID/IR, and the addition line is also IR addition. Rye chromosomes that are distinct to the red-colored wheat chromosomes appear yellow-green at mitotic metaphase after FISH.