Rht12导入八倍体小黑麦及其对小黑麦株高、单株分禁数和种子饱满度的影响

Rht12是位于5A染色体上的显性矮秆基因。用带有该基因的普通小麦Bezostaya1, Mercia作矮源与八倍体小黑麦杂交、回交,经自交和染色体数镜检及田间、室内选择,将Rht12基因导入八倍体小黑麦,获得了染色体数56的矮秆八倍体小黑麦株。在八倍体小黑麦遗传背景下,基因型纯合(Rht12 Rht12)时降秆能力约为41.2%,杂合(Rht12rht12)     

Rht12导入八倍体小黑麦及其对小黑麦株高,单株分蘖数和种子饱满度 …

Ｒｈｔ１２是位于５Ａ染色体上的显性矮秆基因。用带有该基因的普通小麦Ｂｅｚｏｓｔａｙａ１、Ｍｅｒｃｉａ作矮源与八倍体小黑麦杂交、回交,经自交和染色数镜检及田间、室内选择,将Ｒｈｔ１２基因导入八倍体小黑麦,获得了染色体数５６的矮秆八倍体小黑麦株。在八倍体小黑麦遗传背景下,基因型纯合时降秆能力约为４１．２％,杂合（Ｒｈｔ１２ｒｈｔ１２）时约为３１．０％。小黑麦遗传背景对该基因有修饰作用。该基因增强了八倍     

直接导入农林10号矮秆基因于八倍体小黑麦的研究

用杂交、回交方法,将农林10号的矮秆基因导入八倍体小黑麦Y1139F_7中。和预期的一样,在不涉及R组染色体重组的情况下,导入后的八倍体小黑麦种子饱满度并未下降,还略有提高。这是利用直接导入法导入普通小麦有利基因于八倍体小黑麦的第一个实例.为“未经改良的R组染色体对八倍体小黑麦的种子饱满度有干扰作用”提供了间接的证据。     

直接导入农林10号矮秆基因地八倍体小黑麦的研究

用杂交、回交方法，将农林１０号的矮秆是因导入八倍体小黑麦Ｙ１１３９Ｆ７中。和预期的一样，在不及Ｒ组染色体竽组的情况下，导入后的八倍体小黑麦种子饱满度并未下降，还略有提高。审利用直接导入法导入普通小麦有利基因八倍体小黑麦的第一个实例，为“未经改良的Ｒ组染色体对八倍体小黑麦的种子饱满度有干扰作用”提供了间接的证据。     

八倍体小黑麦与七倍体杂种回交配子间竞争规律的研究

当八倍体小黑麦与七倍体杂种回交时,七倍体×八倍体(以下简称“七×八”)组合的子房受精正常,80％的受精子房不能形成有胚乳的种子,有胚乳种子中能成株的仅有20％,回交效率为1％～2％,远低于八倍体×七倍体(以下简称“八×七”)组合的29.07％。通过分析“八×七”回交种子和七倍体F_1杂种根尖染色体数分布发现,八倍体小黑麦雌配子R染色体平均丢失率为0.133,具28染色体数的整倍体配子对27染色体数的非整倍体配子不具有竞争优势;父本七倍体杂种雄配子R染色体的平均丢失率为0.713,整倍体雄配子的竞争能力是非整倍体(染色体数27)雄配子的48.2倍。“七×八”组合回交效率低的原因可能是雌配子间竞争能力低,各种R染色体数的雌配子都能参与双受精,由于不完整的R组染色体对胚乳发育的干扰,大部分合子不能形成能成株的种子。     

390份小麦-黑麦种质材料主要农艺性状分析及优异材料的GISH与FISH鉴定

将小麦近缘属植物黑麦中的优良基因导入小麦可以拓宽小麦的遗传基础,丰富小麦的遗传变异。本研究调查并分析了390份小麦-黑麦种质材料。在这390份种质材料中,6个主要农艺性状值均有较大的极差,说明其遗传多样性丰富。与10份小麦主栽品种相比,90%以上的材料具有穗长和分蘖数的显著优势,60%以上的材料具有小穗数优势,约30%的材料穗粒数和千粒重显著高于主栽品种。利用基因组原位杂交(genomic in situ hybridization,GISH)和多色荧光原位杂交(multicolor fluorescent in situ hybridization,mc-FISH)技术,对8份农艺性状优良的代表性材料进行染色体组成分析,发现3份为六倍体小黑麦(AABBRR),2份为八倍体小黑麦(AABBDDRR),1份为1RS·1BL易位系,其余2份不具有可见的黑麦染色体或染色体片段。值得指出的是,3份六倍体小黑麦与2份八倍体小黑麦所含的黑麦染色体不完全相同。八倍体小黑麦中有1对来源于黑麦的小染色体,而六倍体小黑麦中没有类似小染色体;并且,不同材料中黑麦4R染色体端部的GISH杂交带有明显差异。本研究结果为这些小麦-黑麦种质材料进一步应用于小麦育种提供了依据。     

次级六倍体冬性小黑麦新资源

1978年由墨西哥引入六倍体小黑麦品种(系)196个,其中有一个矮秆品系“TUZ A”(图扎)原产地编号为X-16332-101Y,原粮作室编号为S81245,当年与八倍体小黑麦杂交。目前选育出一批冬性、矮或半矮扦、结实较好、籽粒较饱的六倍体小黑麦新品系。由于我国现有的六倍体小黑麦资源多自国外引入又为春性,所以这些新品系是我国目前较缺乏的新资源。我室可提供少量种子,供遗传,育种工作者利用。详见下表:     

雄性核不育小黑麦在育种上利用的研究

用小黑麦显性核雄性不育系与具有不同性状的小黑麦杂交和回交,建成群体进行轮回选择。经两轮轮选,发现利用轮选改进小黑麦籽粒饱满度(小黑麦育种中限制因素)比用常规系选快一倍。虽然在八倍体核不育系与六倍体小黑麦杂交群体中,随着世代的增加不育株在群体中所占比例逐渐减少,但也有少数后代仍保持1F:1S 的分离比例。说明利用     

八倍体小黑麦与普通小麦杂交的细胞遗传

八倍体小黑麦与普通小麦杂交,后代可以出现亲本类型八倍体小黑麦、普通小麦和普通小麦附加黑麦染色体异附加系与异代换系,对改进八倍体小黑麦的株高、熟期、结实率、籽粒饱满度有一定的效果,也可以选育抗病、耐旱较亲本增产的普通小麦新品种。细胞学观察结果:F₁染色体基本型为21_Ⅱ+7_Ⅰ,F相似文献   

小麦矮杆基因的分子检测及遗传效应研究

利用矮秆基因Rht-B1b、Rht-D1b和Rht8的特异性分子标记对202份普通小麦材料进行了分子检测,连续两年观测了供试材料的重要农艺特性,分析了不同矮秆基因的遗传效应。结果表明:在202份供试材料中,22份供试材料含有基因Rht-B1b,分布频率为10.89%;基因Rht-D1b、Rht8和不含3种矮秆基因的材料分布频率分别为73.76%、65.84%和6.93%,其中有12份材料含基因Rht-B1b+Rht8,有104份材料含Rht-D1b+Rht8,分布频率分别为5.94%和51.43%。矮秆基因对农艺特性的影响不同。3个矮秆基因均可以显著地降低株高,其降秆效应分别为Rht-D1bRht-B1bRht8,就基因组合而言,降秆效应则是Rht-D1b+Rht8Rht-D1bRht-B1b+Rht8Rht-B1bRht8,说明矮秆基因具有累加效应,同时含有2个矮秆基因要比只含有其中1个矮秆基因株高更低。矮秆基因在有效分蘖、穗长、小穗数和穗粒数等方面不存在显著差异,但矮秆基因对有效分蘖有一定的负效应,有利于穗长和穗粒数的增加。基因Rht8可以显著提高千粒重,而Rht-B1b和Rht-D1b对千粒重存在一定的负效应。试验中含有基因Rht-D1b和Rht8的部分材料在农艺性状中表现良好,应进一步加以利用。     

小黑麦不同基因型光合特性的比较

本文就6个不同基因型小黑麦光合特性进行了研究,结果表明不同基因型小黑麦其光合速率、Fo、Fm、Fv/Fm均有显著差异,但不同的光合特性参数差异不同.     

小黑麦中调控花青素合成代谢的MYC基因克隆及序列分析

为了研究蓝粒小黑麦糊粉层中控制花青素合成的关键基因BcMYC1。本研究使用PCR方法克隆小黑麦中MYC转录因子BcMYC1。结果表明,小黑麦BcMYC1基因全长1683 bp,编码的氨基酸560个,分子量61870 Da,等电点4.71,有两个属于bHLH超级因家族的保守区,该蛋白具有亲水性,二级结构以α-螺旋(39.64%)和不规则盘绕(43.93%)为主要的部分,BcMYC1蛋白质不通过跨膜区,在膜外进行作用。蛋白系统进化分析表明,小黑麦的BcMYC1基因与小麦、矮牵牛、水稻等物种MYC调节基因的亲缘关系很高。本研究关于小黑麦中调控花青素合成代谢BcMYC1基因分子遗传机理,为小黑麦的花青素的研究提供参考作用。     

Relative Efficiency of Anther Culture and Chromosome Elimination Techniques for Haploid Induction in Triticale × Wheat and Triticale × Triticale Hybrids

Summary The study was undertaken to evaluate the relative efficiency of anther culture and chromosome elimination (by crosses with maize) techniques of haploid induction in intergenotypic triticale and triticale × wheat hybrids. For this, 15 triticale × wheat and 8 triticale × triticale F₁ hybrids were subjected to anther culture and were also simultaneously crossed with the `Madgran Local' genotype of maize (Zea mays L.) to induce haploids through the chromosome elimination technique. The haploid embryo formation frequency through the chromosome elimination technique was significantly higher in both, triticale × wheat (20.4%) and triticale × triticale (17.0%) F₁ genotypes, as compared to the calli induction frequencies through anther culture (1.6 and 1.4%, respectively). Further, four triticale × wheat and three triticale × triticale F₁ genotypes failed to respond to anther culture, whereas, all the F₁ genotypes formed sufficient number of haploid embryos through the chromosome elimination technique with no recovery of albino plantlets. The haploid plantlet regeneration frequencies were also significantly higher through the latter technique in both triticale × wheat (42.7%) and triticale × triticale (49.4%) F₁s as compared to anther culture (8.2 and 4.0%, respectively), where the efficiency was drastically reduced by several constraints like, high genotypic specificity, low regeneration frequency and albinism. The overall success rates of obtaining doubled haploids per 100 pollinated florets/anthers cultured were also significantly higher through the chromosome elimination technique (1.1% in triticale × wheat and 1.5% in triticale × triticale hybrids), proving it to be a highly efficient and economically more viable technique of haploid induction as compared to anther culture, where the success rates were only 0.2% and 0.1%, respectively.     

Differential Adaptation of Complete and Substituted Triticale

Adaptation of seven complete and twelve substituted triticales to specific soil types has been studied, based on a series of twenty trials carried out in 1989 and 1990 across Spain. The nature of the GE interaction for grain yield was revealed by means of the additive main effects multiplicative interaction (AMMI) model and using the soil pH at the different sites as linear covariate. The percentage of the variability explained by the first principal component axis of the AMMI model was 72 and 65 % for the two years, suggesting a specific pattern of adaptation. Soil pH was the single most important environmental factor to explain the adaptation of complete and substituted types. Complete triticales outyielded substituted genotypes in the majority of sites. Triticale adaptation to acid and alkaline soils seems to be largely controlled by the single wheat/rye chromosome 2D(2R) substitution, for which both types differ. Complete triticales seem better adapted to the acid soils, whereas substituted types are, in general, more suited to alkaline soils.     

Transfer of the Glu-D1 Gene from Chromosome 1D to Chromosome 1A in Hexaploid Triticale

To complement previously developed recombinant chromosomes 1R.1D, two series of translocations involving the Glu-D1 gene from chromosome ID to chromosome 1A were produced in hexaploid triticale. These series involve seven independent transfers of allele d encoding for high molecular weight glutenin subunits 5+10 and ten independent transfers involving allele a encoding for HMW glutenin subunits 2 + 12. The frequency of homoeologous recombination between chromosomes 1A and 1D was within the range observed for pairs of homologues in wheat, supporting earlier observations that homoeologous recombination in triticale is frequent. Recombined chromosomes 1A.1D can be used to introduce the Glu-D1 gene to durum wheats, and to manipulate the dosage of Glu-D1 in hexaploid triticale and bread wheat.     

饲用小黑麦适应性分析

研究了6个冷季型牧草在5个地点的产量表现和饲用品质。结果表明,黔中3号在所有参试品种中产量最高,达2 854kg/667 m2,比对照黑麦草增产410 kg/667 m2;产量稳定性最高,变异度仅为3.55。总的来说,6个品种的饲用品质差异不显著。分析表明,黔中3号可以作为贵州省冷季型牧草品种推广应用。     

Transfer of the Glu-D1 Gene from Chromosome 1D of Breadwheat to Chromosome 1R in Hexaploid Triticale

The use of hexaploid triticale as a crop for human consumption has been limited by its inferior bread-making quality. To ameliorate this problem, a segment of chromosome ID of breadwheat with the Glu-D1d allele encoding for high molecular weight glutenin subunits 5 7plus; 10 was translocated to chromosome 1R of the hexaploid triticale ‘Rhino’ through a combination of a centric break-fusion translocation followed by 5D(5B)-induced homoeologous pairing. The resulting recombinant chromosome 1R has a small interstitial segment of ID with the Glu-D1d allele. The maximum physical length of the translocated segment is estimated at about 16.5 % of 1DL. Frequency of translocations involving the long arms of homoeologous group-1 chromosomes in the analyzed progeny suggested that homoeologous recombination in triticale was substantially higher than that previously reported in hexaploid wheat.     

Cytogenetic Investigations in Wheat, Rye and Triticale

In two rye cultivars and four inbred lines, derived from two different source populations, the extent of polymorphism in the distribution of constitutive heterochromatin was investigated by means of the Giemsa C-banding method. Between the source populations only slight differences appeared, therefore a close relationship has to be assumed. Within open-pollinated cultivars a wide range of variation was found not only for telomeric, but also for interstitial chromosomal bands. Even intracellular polymorphism between homologous chromosomes was observed frequently in cultivars. On the other hand, polymorphism was detected in the lines to a small extent only. Inbred lines show a higher number of constant Interstitial bands than cultivars. In the latter there exist different variants of a certain band, but only one of these variants is manifested in an inbred line drawn from the same source population. Whether this manifestation takes place randomly, or low heterochromatin variants arc preferred, is discussed with regard to the problems of triticale breeding.     

Production and Cytogenetical Analysis of a Rye-Cytoplasmic Tetraploid Triticale

A rye-cytoplasmic tetraploid triticale was found in F_s progenies of crosses between tetraploid rye‘No 1323’and hexaploid triticale‘KT 77′. In the tetraploid triticale, two complete rye genomes and two mixed wheat genomes, consisting of the chromosomes 1A. 2A, 4A, 7A, 3B, 5B, and 6B are present. The rye cytoplasm did not affect stability of rye chromosome pairing during metaphase 1, since rye chromosomes participated in pairing irregularities just as did wheat chramosomes, even on a larger scale. The fertility of F₀, plants ranged from 0 to 75.6 %, always associated with high grain shrivelling. The analyzed pairing behaviour of induced triploid hybrids from crosses between the tetraploid triticale and diploid rye indicates the presence of at least one wheat-rye translocation in one of the investigated triploid plants.