节节麦与野燕麦8倍体杂种核型分析

节节麦(Aegilops tauschii(Coss.)Sch.2n=2x=14)与通北野燕麦(Avena fatua L.2n=6x=42)杂交,F_1自然加倍成8倍体,8倍体播成的F_2代,遗传性基本一致,PMC镜检表明,染色体数为2n=28Ⅱ。用F_2所结的种子进行根尖细胞核型分析,结果发现8倍体中包含有全套的节节麦和野燕麦的染色体。节节麦中有1对随体染色体.2对近中部着丝点染色体,4对中部着丝点染色体。野燕麦有3对随体染色体,5对近端着丝点染色体,8对近中部着丝点染色体,5对中部着丝点染色体。而节节麦与野燕麦8倍体杂种,有4对随体染色体,5对近端着丝点染色体.10对近中部着丝点染色体,9对中部着丝点染色体。核型分析结果表明,节节麦与野燕麦杂交合成的8倍体,是节节麦与野燕麦的双二倍体。     

节节麦与野生燕麦杂种F2研究

节节麦Aegilops tauschii(Coss.)Sch.2n=2x=14与通北野燕麦Avena Fatua L.2n=6x=42杂交,F_1代为双二倍体,2n=56。F_2代主要群体为双二倍体,2n=56。有一部分为2n=27Ⅱ,也出现一部分为2n=54,有2～4个单价体。出现个别的7倍体类型,穗型属斯卑尔脱小麦型,结实率极低,不足0.5%,籽粒饱满,100粒重4.75克。PMC染色体构图为2n=21Ⅱ 7Ⅰ。出现极少数的5倍体类型,株型和穗型类似节燕双二倍体,但结实率极低,染色体构图为2n=14Ⅱ 21Ⅰ。并出现普通小麦型,共2株,株高78.1和81.5厘米,籽粒基本饱满,100粒重4.34克和3.92克。PMC染色体构图为2n=21Ⅱ。     

四倍体小黑麦新种——节节麦-森林黑麦双二倍体

节节麦-森林黑麦双二倍体系作者用原产河南和伊朗的节节麦(Triticum tauschii,DD,2n=14)作母本,分别与引自英国的森林黑麦(Secale sylvestre,RsRs,2n=14)杂交,经染色体加倍而合成的四倍体小黑麦新种。其染色体组为DDRsRs,2n=28。     

偏凸山羊草的核型和C-带研究

通过对偏凸山羊草的核型和C-带分析研究表明,偏凸山羊草的D染色体组与节节麦的D染色体组很相似,其可能来自于节节麦;M^V染色体组臂比较大,有2对普通小麦所没有的近端着丝粒染色体,且所显C-带带型与普通小麦的染色体组有明显区别。     

利用六倍体小黑麦×普通小麦培育伴随易位的非整倍体

用核型和GiemsaC—带技术对六倍体小黑麦×普通小麦的杂种后代（F4）83C3796和83C3804混系今的非整倍体进行了分析。在74个随机抽样的细胞中，染色体数从35条到43条都有分布，比率分别是4．05％、5．40％、2．7O％、9．46％、9．46％、12．16％、12．16％、41．89％和2．70％．发生小麦染色体丢失的植株频率超过55．39％，2n－13植株出现的比率最低（占2．70％）．并从一般核型中观察到染色体游离片段和染色体“断裂一融合”过程．C一带分析观察到高频率的小麦一黑麦染色体易位，都属罗伯逊易位．易位包含了小麦的A、B、D组染色体和黑麦所有14条染色体臂，其中IRS易位频率最高（占48．3％），且全为纯合易位，其它易位染色体纯合的程度各自不同．研究中还观察到在一个细胞中有多个小麦一黑麦染色体易位共存的现象．文中还讨论了易位非整倍体在小麦育种上的利用问题。     

节节麦与野生燕麦杂交研究

节节麦Aegilops tauschii (Coss·) Sch,2n=2x=14与通北野生燕麦Avena fatua L·2n=6x=42直接杂交成功。F_1有两株,一株优势很强,成穗143个,另一株生长很弱,从苗期开始脚叶就逐渐黄化,成穗14个。经花粉母细胞镜检表明,生长势很强的杂种,是自然加倍的双2倍体,染色体数为2n=8x=56。生长弱的杂种植株,是7倍体,染色体数基本上是2n=7x=49。这2株杂种芒长在护颖和外颖的背上,具有燕麦族芒长在外颖背上的族的特征性状。这2株杂种对国内白粉菌小种均表现免疫。节节麦及其他山羊草种,基本上是不抗白粉病的。7倍体植株的结实率极低。     

一种野生燕麦的染色体核型分析

对安徽风阳地区麦田里的一种野生燕麦的染色体核型进行了分析，结果如下：该物种的染色体数为2n=42，各染色体间形态差异明显，但均为中着丝粒染色体（m）或近中着丝粒染色体（sm），最长与最短染色体相对长度比为2．34，并在全套染色体中的第9号和16号染色体上发现了2对随体，核型公式为2n=6x-42=22m＋20sm（2SAT），核型类型舅比较对称的2B型。同时讨论了燕麦作为小麦遗传改良的重要种质资源，对普通小麦远缘杂交和品质改良的意义。     

Presto×晋农190杂种F_2-3及双亲的核型分析

为创制六倍体小黑麦(TriticosecaleWittmack)-普通小麦(Triticum aestivumL.)异染色体体系,将六倍体小黑麦的优良基因导入到普通小麦中,以六倍体小黑麦品种Presto为母本、普通小麦品种晋农190为父本,配置杂交组合,对双亲及其杂种F2种子根尖细胞进行有丝分裂观察,确定其染色体数目并进行核型分析。结果发现,双亲的染色体数目均为42,父本晋农190的核型公式为2n=42=36m(2SAT)+6sm,核型类型为1A;母本Presto的核型公式为2n=42=26m(4SAT)+4M+12sm,核型类型为2A。杂种F2中F2-3为双单体附加系,其核型公式为2n=44=36m(3SAT)+4sm+1m+1m,核型类型为1A。通过对染色体的形态、短臂和长臂的长度、臂比及相对长度系数进行分析,可初步推断杂种F-3附加的可能是母本的7号和21号染色体。     

人工合成的种质资源——节节麦×乌拉尔图小麦的双二倍体

作者以节节麦(Aegilops squarrosa L.)(原产高加索,编号为AE231177,2n=14,从民主德国引进)作母本,与乌拉尔图小麦(Triticum urartu Thum ex Gandil.)(编号为Hiki6735 78,2n=14,     

野生二粒小麦与野燕麦杂种核型研究

1989年用野生二粒小麦(Triticum dicoccoides Corn.2n=4x=28)与通北野燕麦(Avenafatua L.2n=6x=42)杂交成功,F_2分离出燕麦型、二粒小麦型、硬粒小麦型、斯卑尔脱型和普通小麦型。斯卑尔脱型F_4中的一个类型,与双亲野生二粒小麦和通北野燕麦的核型进行比较研究。杂种中有一对近端着丝点染色体,5对随体染色体。近端着丝点染色体来源于通北野燕麦,5对随体染体来源于双亲野生二粒小麦和通北野燕麦。证明野生二粒小麦与通北野燕麦杂种斯卑尔脱型是真杂种。     

小麦属2个种间杂种及3个亲本的核型分析

【研究目的】本研究旨在通过细胞学鉴定判断小麦属2个种间杂种的真实性,了解其亲本的染色体组及倍数性;【方法】本试验采用了常规染色体组型分析方法;【结果】分析和报道了小麦属2个种间杂种及其3个亲本的核型,根据核型分析的有关参数,阐明了两个杂种1894×Ps5、新7×Ps5及其亲本新7、1894和Ps5的核型特征,其核型分别为：新7(2n=6x=42)：2M+12sm+28m(2SAT)(2B),1894(2n=6x=42)：2M+20sm+18m(2SAT)+2st(2B),Ps5(2n=4x=28)：2M+12sm(2SAT)+12m+2st(2B),1894×Ps5(2n=5x=35)：2M+19m+12sm+2st(2B),新7×Ps5(2n=5x=35)：1M+21m+13sm(2B);【结论】由此鉴定了2个杂种的真实性--均为真杂种,并确认了亲本新7和1894的第一套和第二套染色体均分别为A组和B组,倍数性均为6x,它们的第三套染色体属什么染色体组有待进一步研究。     

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     

渥丹百合不同居群核型研究

采用染色体常规压片的方法,对渥丹百合(Lilium. concolor Salisb.)4个居群进行了染色体核型分析,结果表明,有斑百合BH27 (L. concolor var. buschianum Baker.) 和有斑百合BH41 (L. concolor var. buschianum Baker.)核型分别为2n=2x=4m(2SAT)+4st+16t(2SAT)和2n=2x=4m(4SAT)+12st+8t(4SAT),黄花渥丹BH20(L. concolor var. concolor f. coridion Kitag.) 核型为2n=2x=4m(4SAT)+4st+16t(4SAT),大花百合BH50 (L. concolor var. megalanthum Wang et Tang) 核型为2n＝2x=4m(4SAT)+6st(2SAT)+14t(4SAT);其核型分类都属于3B型,但结构变异明显,主要表现在染色体相对长度、臂比、次缢痕数目及分布。     

Expression of a Triticum turgidum var. dicoccoides source of Fusarium head blight resistance transferred to synthetic hexaploid wheat

Yield and quality reductions caused by Fusarium head blight (FHB) have spurred spring wheat (Triticum aestivum L.) breeders to identify and develop new sources of host plant resistance. Four wheat synthetic hexaploids (×Aegilotriticum sp.) were developed, each having a quantitative trait locus (QTL), Qfhs.ndsu‐3AS, providing FHB resistance from Triticum turgidum L. var. dicoccoides chromosome 3A. Synthetics were produced by hybridizing a ‘Langdon’‐T. dicoccoides‐ recombinant chromosome 3A substitution line (2n = 4x = 28, AABB with two accessions of T. tauschii (2n= 2x = 14, DD). Synthetics were inoculated and evaluated for FHB resistance in two separate greenhouse seasons. One synthetic, 01NDSWG‐5, exhibited FHB severity ratings of 36% and 32% in the separate seasons, compared with ratings of 9% and 30% for ‘Alsen’, a FHB‐resistant spring cultivar, and ratings of 70% and 96% for ‘McNeal’, a susceptible spring cultivar, respectively. Synthetic × Alsen backcross‐derived lines were produced to initiate combining different sources of FHB resistance.     

Wide hybridization between wheat (Triticum L.) and lymegrass (Leymus Hochst.)

A total of 240 F₁ hybrids was made beween wheat (Triticum aestivum L. em. Thell. (2n = 6x = 42) and T. carthlicum Nevski (2n = 4x = 28)) and perennial lymegrass (North European Leymus arenarius (L.) Hochst. (2n = 8x = 56) and North American L. mollis (Trin.) Pilger (2n = 4x = 28)). The wide crosses yielded embryos in 20% of caryopses and 96% of the embryos developed into normal hybrid plants. The hybrids were vegetatively vigorous, with evidence of the Leymus rhizomatous habit. Those deriving from L. arenarius survived overwintering in Iceland, but the hybrids L. mollis did not, whereas in a milder environment, both showed perenniality. Cytogenetic analysis of root tip cells before the plants were treated with colchicine showed that 21 out of 28 hybrids investigated had chromosome mosaics, with a population of both amphihaploid and amphidiploid cells. This spontaneous doubling of somatic chromosomes occurred in all cross combinations, with the highest average frequency of diploid cells (28%) in T. carthlicum × L. arenarius crosses. A few selfed seeds have been obtained from a T. aestivum × L. arenarius hybrid. All the hybrids were treated twice with colchicine, but the treatment appeared to have little or no effect on the frequency of chromosome doubling in the hybrids deriving from T. aestivum. The frequency of diploid cells, however, increased significantly (e.g. to 80%) in the hybrids deriving from the T. carthlicum parent. Genomic in situ hybridization confirmed the hybridity of the plants and showed that the hybrids were amphiploids containing genomes of both wheat and lymegrass. In situ hybridization using ribosomal DNA probe differentiated chromosomes of L. mollis, L. arenarius from those of wheat. The hybrids are being backcrossed with lymegrass pollen, aiming to domesticate the wild, perennial species. This revised version was published online in July 2006 with corrections to the Cover Date.     

Wheat EST-SSRs for tracing chromosome segments from a wide range of grass species

Transferability of 116 common wheat expressed sequence tag–simple sequence repeats (EST-SSR) markers was investigated on 168 accessions representing 18 grass species to identify new alleles useful for wheat improvement. Transferability among the Triticeae ranged from 73.7% for Aegilops longissima to 100% for wheat subspecies ( Triticum compactum ) but was also good for less related species such as rye (72.8%) or maize (40.4%). On average, the number of alleles/locus detected by EST-SSR markers was 3.1 for hexaploid wheat. The polymorphism information content (PIC) values simultaneously estimated for Triticum aestivum and Triticum durum were similar for the two species (0.40 and 0.39, respectively). The allelic diversity within allogamous species was higher (0.352–0.423) compared with that of T. aestivum and T. durum (0.108 and 0.093, respectively). T. aestivum and T. durum shared the largest number of alleles (74.6%) while among the three ancestral diploid species of bread wheat, Aegilops tauschii had the highest percentage of alleles with T. aestivum (57.4%). These results indicate that grass orphan species can be studied using wheat EST-SSRs and can serve as a source of new alleles for wheat genetic improvement.     

CIMMYT新型人工合成小麦Pina和Pinb基因等位变异

六倍体人工合成小麦由硬粒小麦（Triticum turgidum subsp. durum）与粗山羊草（Aegilops tauschii Coss.）杂交产生,是研究小麦进化过程中基因变异的重要材料。以国际玉米小麦改良中心（CIMMYT）提供的57份由野生二粒小麦（T. turgidum subsp. dicoccoides）与粗山羊草杂交产生的新型人工合成六倍体小麦为材料，用单籽粒特性测定仪和Pina、Pinb特异性PCR引物对其籽粒硬度变异以及控制籽粒硬度的主效基因Pina和Pinb的分布情况进行了研究。结果表明，这些材料的SKCS硬度值变异较大，从10.5到42.6，其中15~30的占78%。共有Pina-D1a、Pina-D1c、Pinb-D1h和Pinb-D1j 4种等位变异型，基因型为Pina-D1a/Pinb-D1j的8个，占14%；基因型为Pina-D1c/Pinb-D1h的49个，占86%。方差分析表明，基因型Pina-D1a/Pinb-D1j与Pina-D1c/Pinb-D1h对籽粒硬度的影响差异不显著，但父本粗山羊草和母本野生二粒小麦以及二者间的互作对籽粒硬度有显著影响，说明除Pina和Pinb外，还有其他微效基因影响籽粒硬度的形成。     

伴生栽培小麦产量与品质性状的研究

为了解伴生栽培小麦产量和品质性状及合理开发利用伴生栽培小麦的优异性状,以6个伴生栽培小麦基因型和6个普通栽培小麦基因型为试验材料,对伴生栽培小麦产量与品质性状进行了研究。结果表明,伴生栽培小麦收获指数平均值为0.3823,普通栽培小麦比其高了28.0%,两者差异极显著;伴生栽培小麦单株穗数比普通栽培小麦多6.0穗,多出幅度为50.5%,两者差异极显著,千粒重平均值为26.38 g,普通栽培小麦是伴生栽培小麦的1.68倍,差异极显著,穗粒数差异不显著;6个伴生栽培小麦的蛋白质含量平均值为14.53%、湿面筋含量平均值为37.00%、沉降值的平均值为30.72%,均高于普通栽培小麦,差异极显著,水分为12.82%,小于普通栽培小麦,与普通栽培小麦比较差异显著。     

Agronomic Variability in Selected Triticum turgidum x T. tauschii Synthetic Hexaploid Wheats

Two trials were conducted at the Mexican National Institute of Agricultural Research Experiment Station at Yaqui Valley, Sonora, Mexico to investigate the nature and extent of agronomic variation in 50 synthetic hexaploid (SH) wheats (2n = 6x = 42, AABBDD) derived from Triticum turgidum (2n = 4x = 28. AABB) × T. tauschii (In = 2x = 14, DD) crosses for subsequent use in wheat improvement. Plant height, spike length, days to flowering, physiological maturity, grain yield, above-ground biomass at maturity, harvest index, yield components and test weight were determined.
Significant agronomic variation was observed among the germplasm evaluated. Outstanding SH genotypes were identified with higher grain yield, above-ground biomass at maturity, 1000-grain weight, and spikes m⁻² than the bread wheat ( Triticum aestivum L.) check cultivar Seri 82. Genotypic correlations of grain yield with other character traits show that grain m² was the most important determinant of gram yield (r = 0.993). Data on agronomic traits subjected to complete linkage cluster analysis resulted in classifying the genotypes into two distinct phenotypic groups excluding Seri 82. Groups generally corresponded to durum progenitors of the SH with significant group differences for all characters. This demonstrates use of practical numerical analysis procedures to describe agronomic variation in representative SH genotypes. Clustering by quantitativy traits may be valuable for identification of genotypes with divergent sources for breeding and agronomic purposes.     

Genetic analysis of glume colour in common wheat cultivars from the former USSR

Genotypes for the glume colour character have been studied in 27 cultivars of common wheat (Triticum aestivum L.) originated from old landraces, and 1 specimen of T. petropavlovskyi Udacz. et Migusch. by means of analysis of the F₂ populations. The following tester lines have been used: white-glumed ‘Novosibirskaya 67’ ‘Diamant I’, and ‘Federation’, carrying the Rg1 gene alone; lines RL5405 and near-isogenic ‘Saratovskaya 29’ *5 (T. timopheevii Zhuk./T. tauschii (Coss.) Schmal.), carrying Rg2; line (1A ‘CS’ × ‘Strela’) with Rg3. The red glume colour in 21 cultivars of Triticum aestivum and in the accession of T. petropavlovskyi has been shown to be determined by the single gene Rg1, located on chromosome 1B. Five cultivars carrying the gene Rg3 for red glumes on chromosome 1A have been revealed. The cultivars ‘Zhnitsa’ and ‘Iskra’ carry the gene Rg3 alone. The red glume colour in the cultivars ‘Milturum 321’, ‘Milturum 2078’, ‘Sredneural'skaya’ is controlled by two genes, Rg1 and Rg3. In two common wheat cultivars, ‘Sarrubra’ and ‘Krasnoyarskaya 1103’ the red glume colour is determined by Rg1, inherited from local populations (‘Turka’ and ‘Kubanka’ respectively) of tetraploid wheat T. durum Desf. var. hordeiforme Host. Wide occurrence of the Rg1 gene in common wheat has been confirmed. On the contrary, none of the investigated varieties carries the gene Rg2. This revised version was published online in July 2006 with corrections to the Cover Date.