小麦梭条花叶病抗性的遗传研究

本试验选用17个高抗品种、 9个高感品种随机组合进行杂交, 通过对F1、 F2和部分BC1、 BC2的抗感鉴定结果以及F3代的追踪分析, 研究了小麦品种对小麦梭条花叶病的抗性遗传规律。 结果表明, 小麦品种对小麦梭条花叶病的抗性为细胞核遗传, 这一性状受多对显性基因的控制, 不同品种含有其中的一对或两对或三对, 大多数品种     

小麦梭条花叶病的发生与防治

小麦梭条花叶病是小麦梭条花叶病毒引起的一种病毒病。小麦病株分蘖少,主茎成穗率低,穗小、粒轻,发病田块一般减产10%~20%,严重的可达70%以上。介绍了小麦梭条花叶病的发病规律及发病症状,并从农业防治和化学防治方面提出了防治对策。     

普通小麦-黑麦抗白粉病异附加系的鉴定

以抗病性强的奥地利黑麦（Secale cereale L.）为父本，与陕麦611杂交、自交，在衍生后代中筛选出表型整齐一致且抗白粉病性好的株系1530W3和1493E3。研究表明，两个衍生系在形态学和细胞学上已基本稳定，染色体构型为2n=44=22II。采用122个SSR引物对两个衍生系及其亲本进行SSR分析，有5个引物在两个衍生系中可扩增出黑麦的特异性产物，结果表明，黑麦的遗传物质已经导入到普通小麦中。     

抗白粉病小麦-黑麦染色体异附加系的选育

本研究以白黑麦和六倍体小黑麦WOH45为抗源,综合应用白粉病抗性鉴定,细胞遗传学、花药培养等技术选育出抗白粉病单体,单端体、单等臂染色体,二体,双端体异附加系。单体(单端体)异附加系的遗传极不稳定．在其自交后代中抗病株的频率为13．4％-34．6％,其白粉病抗性的配子传递宰特别是橇配子传递率较低,致使在其自交后代     

南阳主要推广小麦品种对小麦黄花叶病的抗性鉴定

利用田间抗性鉴定和病毒检测方法,对南阳主要推广小麦品种进行了小麦黄花叶病的抗性鉴定和检测.结果表明,供试品种均感染了小麦黄花叶病毒;不同小麦品种对小麦黄花叶病抗性有显著差异,高抗、中抗、中感和感的品种分别占筛选品种的6.67%、46.67%、33.33%和13.33%.     

小麦-黑麦代换系间、代换系与易位系间杂交后代染色体易位系的选育

为了选育有经济价值的易位系,探讨小麦-黑麦间产生易位的频率,本研究以小麦-黑麦代换系DS5R/5A和DS6R/6A为母本,以小麦-黑麦易位系克珍(Kezhen)和带有杀配子染色体的代换系DSGC1为父本,分别进行田间杂交。结果表明:DS5R/5A、DS6R/6A与DSGC1(2S)杂交结实率低,平均为27.7%,与克珍(T3B.3R)杂交结实率高于前者,平均结实率为59.3%,二者均好于远缘杂交的结实率,这也表明带有杀配子染色体的亲本影响结实率;对选出的54株DS5R/5A×DSGC1、DS6R/6A×DSGC1杂种后代与80株DS5R/5A×克珍、DS6R/6A×克珍杂种后代进行C-分带、原位杂交和分子标记鉴定后发现,二者的易位频率分别为11.1%和8.8%,并且多为染色体端部小片段易位,这种小片段易位可能是代换系间杂交部分同源染色体交换产生的。此外,也表明杀配子染色体在引起染色体断裂后可发生染色体易位。本研究共获得T5RL.5AS、T5RS.5DL、T5RS.5BL、T6RL.6DS、6RL.6BS以及T6RS.6BL等13个易位系,平均易位频率为9.6%。     

小麦-黑麦代换系鉴定及其杂交诱导易位分析

小麦-黑麦易位系在小麦染色体工程中有重要的应用,由于黑麦是小麦的近缘种属,抗病、抗逆性强,具有许多优良性状基因,是改良小麦的重要基因库。代换系代换的是整条染色体,因此它的细胞学稳定,生活力强。因此,被鉴定出的小麦-黑麦易位系具有诸多优点,在经过田间筛选后可以直接用于生产。本研究应用C-分带和原位杂交的方法进行细胞学鉴定,鉴定出代换系4个,易位系2个,并对C-分带和原位杂交实验技术的主要影响因素也进行了探讨,这对小麦品种改良具有重要意义。     

普通小麦品种中Ph基因突变体自然存在的可能性研究

本试验用50个日本普通小麦品种与兰州黑麦杂交,通过对杂种F1花粉母细胞减数分裂染色体行为进行观察,对36个组合F1的PMC染色体配对频率进行统计分析,发现农林20,沙丘小麦和农林9三个品种与黑麦杂种F1PMC染色体配对频率明显高于其它组合,分别为2.84、3.59、3.06。近似于对照组合“中国春×兰州黑麦”F1(为1.37)的两倍。认为     

普通小麦中外源异染色质的检测研究进展

小麦近缘植物存在着极为丰富的遗传多样性和可供改良小麦的优异基因,加强小麦与其近缘植物的杂交、外源异染色质的检测和利用研究,必将为小麦生产和育种带来更大的进展。本文概述了形态标记、细胞标记、生化标记和分子标记在小麦外源异染色质检测中的研究进展,并对其作了简要的评价。     

野小麦的叶锈病和条锈病抗性基因向普通小麦中的转移

在本研究中，我们测试了对几种叶锈病致病型具有抗性新基因的一个品系，并且确定了这些新基因的染色体位置。Lr53／Yr35的原始材料是用“中国春”（CS）育成的一个近等基因系98M71，系谱为野小麦（T.dicoccoides）479／4＊CS／／3＊CS-S／3／（CS），CS-S具有与“中国春”相同的病害反应，是一个半矮性（RHT-B16）近等基因系，其系谱为Inia66／7＊CS。研究发现，导入野小麦连锁的叶锈病和条锈病抗性基因使普通小麦幼苗避开了有关病原菌致病型的侵害。     

Effects of Wheat Chromosome 1D Telosomes on Hybrid Seed Development in Wheat × Rye Crosses

Pollination of ‘Chinese Spring,’ monosome 1D plants with rye results in failure of hybrid seed development in a proportion of the F₁ seeds corresponding to the transmission rate of the nullisomic 1D egg cells. Development and viability of these hybrid seeds closely resemble that normally observed in T. aurum× rye crosses. Using ‘Chinese Spring’ chromosome ID telosomic plants in crosses with rye, it was possible to illustrate that the observed effect was associated with the long arm of this chromosome.     

Intergeneric Transfer (Rye to Wheat) of a Gene(s) for Russian Wheat Aphid Resistance

An octoploid triticale was derived from the F, of a Russian wheat aphid-resistant rye, ‘Turkey 77’, and ‘Chinese Spring’ wheat. The alloploid was crossed to common wheat, and to ‘Imperial’ rye/‘Chinese Spring’ disomic addition lines. F₂, progeny from these crosses were tested for Russian wheat aphid resistance and C-banded. A resistance gene(s) was found to be associated with chromosome arm IRS of the ‘Turkey 77’ rye genome. A monotelosomic IRS (‘Turkey 77’) addition plant was then crossed with the wheat cultivar ‘Gamtoos’, which has the 1BL.1RS ‘Veery’ translocation. Unlike the IRS segment in ‘Gamtoos’, the ‘Turkey 77’-derived 1 RS telosome did not express the rust resistance genes Sr31 and Ar26, which could then be used as markers. From the F, a monotelosomic 1 RS addition plant that was also heterozygous for the 1BL. 1 RS translocation was selected and testerossed with an aphid-susceptible common wheat, ‘Inia 66’ Meiotic pairing between the rye arms resulted in the recovery of five euploid Russian-wheat-aphid-resistant plants. One recombinant also retained Sr31 and Lr26 and was selfed to produce translocation homozygotes.     

Dosage Response of Rye Genes in a Wheat Background

Wheat (Triticum aestivum L.) breeders often utilize alien sources to supply new genetic variation to their breeding programs. However, the alien gene complexes have not always behaved as desired when placed into a wheat background. The introgressed genes of interest may be linked to undesirable genes, expressed at low levels or not at all. The short arm of rye (Secale cereale L.) chromosome one (1RS) contains many valuable genes for wheat improvement. In order to study rye gene response to varying copy number, wheat lines were constructed which contained zero, two or four doses of 1RS. The meiotic behavior of rye chromosome 1R, and wheat/rye translocation chromosomes, 1AL/1RS and 1BL/1RS was studied in the F₁ hybrids between wheat lines carrying 1R or the translocation chromosomes. The IRS arm was transmitted at a very high frequency; 98 % of the F₂ plants had at least one of the chromosomes with a IRS arm. In addition, 44 % of the F₂ plants received at least one copy of the chromosomes from each parent. Analysis of the meiotic behavior of the IRS arm suggested that few euploid wheat gametes were formed. Therefore, most of the pollen must have contained IRS. It is unknown whether the lack of euploid wheat pollen could account for the high transmission frequency of the rye chromosomes. There may have been differential survival of the embryos receiving the rye chromosome as well.     

Agronomic Performance of Hexaploid Wheat Lines Derived from Direct Crosses between Wheat and Aegilops squarrosa1)

Direct introgression of genes from diploid Aegilops squarrosa L into hexaploid wheat (Tnticum aestivumL.) is an efficient way of developing stable, hexaploid lines with unique, useful genes. 39 such lines derived front direct crosses to determine the effects of Ac. squarrosa germplasm were field-tested on productivity. Whereas some lines were agronomically inferior to the recurrent parent, others periormed at an equall or better level. In addition to the larget traits (Hessian-fly and leaf-rust resistance), other traits, including soilborne-mosaic-virus resistance and protein concentration, were improved.     

小麦耐水分胁迫突变体生理及RAPD特性分析

检验小麦耐水分胁迫突变体对渗透胁迫环境的耐受能力并对其生理生化及分子特性进行研究。测定突变体愈伤组织在甘露醇,NaCl和聚乙二醇(PEG-6000)模拟的渗透胁迫下的相对生长量及其在20%甘露醇胁迫下游离脯氨酸含量、可溶性糖含量、可溶性蛋白含量等生理生化指标,并进一步检测了突变体再生苗的K /Na 含量及可溶性蛋白质组成和基因组DNA RAPD多态性等生化和分子特征。突变细胞系可以在对照不能生长的20%甘露醇、1.5%NaCl和20%PEG-6000胁迫条件下,分别表现出14.5%,12.8%,41.8%的相对生长量;在20%甘露醇胁迫条件下突变细胞系游离脯氨酸积累量为对照的80%,可溶性糖积累量为对照的1.2倍,可溶性蛋白含量为对照的1.3倍。在相同浓度的甘露醇模拟的渗透胁迫环境中突变体再生植株比对照植株相能维持较高的K /Na 比值。与对照相比,耐水分胁迫突变体再生植株可溶性蛋白SDS-PAGE发生显著变化:6条新可溶性蛋白谱带出现在突变体再生植株中,同时对照系中的1条可溶性蛋白谱带在突变株中缺失。突变体植株与对照株RAPD带型呈现一定的多态性。所研究的小麦耐水分胁迫突变体是一个具有较强渗透胁迫耐受能力,可用于进一步育种工作的良好中间材料。     

Effect of Diclofop and Linuron on Rye Grass (Lolium multiflorum), Control in Triticale (X Triticosecale), Wheat (Triticum aestivum), and Rye (Secale cereale)

Annual rye grass ( Lolium multiflorum Lam.) is a serious and wide spread problem in cereal crops. A field experiment with a promising herbicide diclofop [(±)-2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid] at 0.56, 0.84 and 1.12 kg ai/ha, in comparison to commonly used linuron [ N' -(3,4-dichlorophenyl)- N -methoxy- N -methylurea] at 0.84, 1.12 and 1.41 kg ai/ha was conducted to control rye grass ( Lolium multiflorum Lam.) in triticale (X Triticosecale Wittmack), wheat ( Triticum aestivum L.) and rye ( Secale cereale L.). The herbicides were applied as soil-incorporated, preemergence and post-emergence. Results showed that diclofop is less phytotoxic than Linuron and the postemergence application of these herbicides was more phytotoxic on all cereal crops. Diclofop applied at 1.12 kg/ha, gave almost 100 percent rye grass control and produced 45 and 115 kg/ha higher grain yields in pre- and postemergence methods, respectively, as compared to the soil-incorporated method.     

小麦-冰草附加系与小麦-杀配子染色体附加系杂交F1的细胞学特性

以小麦-冰草附加系与中国春-柱穗山羊草杀配子染色体2C附加系杂交,对杂交F1的形态学及细胞学特性进行了研究,为利用杀配子染色体诱导小麦ABD组和冰草P组染色体变异,创造小麦-冰草染色体易位系奠定基础。对8个小麦-冰草二体附加系同中国春-杀配子染色体附加系杂交F1的形态学、育性以及细胞学特性的观察结果表明,小麦-冰草不同附加系P染色体的传递能力存在差异。F1花粉母细胞减数分裂中存在染色体异常,平均35.3%的细胞含3个以上的单价体,74.0%的四分体含有微核,20.3%和23.8%的细胞含有染色体断片和桥,在某些组合中有多价体、四分体多裂和退化现象。杀配子染色体的诱变在配子形成的过程中已经开始发生作用。不同杂交组合之间F1植株自交结实率为51.67%-71.37%,反映出杀配子染色体2C在小麦-冰草不同附加系背景下对其育性的影响存在差异。     

小麦K、V、T、CHA细胞质雄性不育类型的光合特性分析

利用2套同核异质的K、V、T、CHA型不育系及其保持系,对其不同生长发育时期的光合特性及光合产物的积累进行分析研究,探讨不同小麦雄性不育类型的胞质效应。结果表明: (1)叶绿素含量在各个材料中表现不同,K、V、T型不育系与保持系相差不大,也未表现出不良效应,CHA型抽穗期的叶绿素含量为2.368～1.253 mg/g,较K、V、T型不     

Effect of D-Genome Chromosome Substitutions on Hybrid Seed Development and Viability in T. turgidum var. durum X S. cereale Crosses

Triticum turgidum var. durum cv. ‘Langdon’ and the set of D-genome disomicsubstitutions in ‘Langdon’, produced at Fargo, U.S.A., were grown in a temperature controlled greenhouse and crossed with diploid spring rye (Secale cereals), to determine the effect of each substitution on 1. the crossability with rye, and 2, the viability of the resulting hybrids kernels. None of the disomicsubstitutions lines, with the possible exception of the 5D (5Bj line, gave an appreciable improvement in hybrid kernel set, -development, and -viability over the control, ‘Langdon’ The post-zygotic barrier to endosperm and embryo development, which operates in crosses between durum wheat and rye, could therefore not be suppressed by any specific chromosome of the D-genome.