节节麦远缘杂种胚的组织培养(简报)

利用活体-离体胚培养和胚愈伤组织诱导、再生植株技术有效地克服了节节麦远缘杂种胚的败育,高效产生了节节麦与硬粒小麦-簇毛麦双倍体、六倍体小黑麦、小麦、大麦间的杂种植株,从而为节节麦种质利用提供了技术方法。     

节节麦×普通小麦杂种的胚援救和胚愈伤组织再生植株

通过活体-离体胚培养和胚愈伤组织培养有效地克服了节节麦(Aegilops tauschii Cosson.)×小麦(Triticum aestivum L.)杂种幼胚的败育,产生了大量的杂种植株。采用活体-离体胚培技术,节节麦×小麦三个组合杂种幼胚的成苗率为55%,是前人所用传统胚培方法成功率的5—20倍。杂种幼胚在添加有2 mg/L 2,4-D的MS培养基上诱导为愈伤组织,经继代产生全能性愈伤组织,继而分化出再生植株。愈伤组织经继代保存150天仍不丧失分化能力。本文还对两种产生杂种的组织培养方法进行了比较研究。     

普通小麦与鸭茅摩擦禾的远缘杂交：Ⅲ.受精和早期胚的发育

用石蜡制片法和整体解剖法,对小麦品种Ｆｕｋｕｈｏ经鸭茅状摩擦禾花粉粉后不同时间固定的子房样品进行了细胞胚胎学观察。结果表明,观察的１６８个授粉后１２０小时以内的小麦了房中有３２．１％、０．６％和２６．２％分别发生了卵细胞单受精、极核单受精和卵卵细胞、极核双受精现象。     

节节麦×硬粒小麦-簇毛麦双二倍体杂种F_1可孕配子形成途径的细胞学分析

对节节麦×硬粒小麦-簇毛麦双二倍体杂种F_1减数分裂的观察结果表明:该杂种F_1的可孕性是由于杂种F_1产生了大量的(近于)未减数配子的结果。在一些PMC中,单价体中期Ⅰ集结到赤道板上,后期Ⅰ染色单体均等分离产生二分体,二分体发育成有功能的花粉粒。由于染色(单)体的丢失或不分离可产生大量的不完整的重复、缺失未减数配子,完整未减数配子的频率很低。杂种F_1和普通小麦杂交一代及F_2代的细胞学分析结果和F_1配子形成途径分析结果一致。推测从大量的F_2代中可能筛选到自发八倍体(DDAABBVV)。     

麦田节节麦发生动态及其对小麦产量的影响

于2009—2011年采用固定样方和随机样方取样的方法研究了山东肥城、河北永年和河南新乡3个地区冬小麦田节节麦的出苗规律及在田间的消长动态,同时研究了不同密度的节节麦对小麦生长的竞争效应。结果表明,节节麦的出苗、分蘖、株高和鲜重的变化与温度密切相关。节节麦有2个出苗高峰期,分别在冬前10月下旬—11月上旬和春季3月下旬—4月上旬。节节麦单株有效分蘖在山东省、河北省及河南省分别多于小麦3.0、3.4个/株和2.2个/株。节节麦对小麦产量的影响主要是通过抑制小麦的有效穗数而实现,对千粒重影响不明显,当节节麦密度为640穗/m2时,小麦产量损失率达28.38%。     

小麦×长穗偃麦草的受精和早期胚胎发育

用石蜡切片法,对小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）和长穗偃麦草（Ｅｌｙｔｒｉｇｉａｅｌｏｎｇａｔａ）杂交的受精和早期胚胎发育进行了观察。结果表明,长穗偃麦草花粉在小麦柱头上萌发良好,花粉管可顺利长入花柱和胚囊。观察的１７０个小麦子房中,１７６５％发生了双受精,产生了胚和胚乳;９４１％发生了单卵受精,只产生胚而无胚乳;４７１％发生了单极核受精,只产生胚乳而无胚;总受精率为３１７７％;成胚率为２７０６％。由于胚乳的缺乏或发育异常及败育,最终难以获得有生活力的种子。为小麦与长穗偃麦草远缘杂交提供了细胞胚胎学证据。     

节节麦×大麦杂种胚再生植株的细胞遗传学研究

以节节麦(2n=14)为母本和大麦(2n=14)进行杂交,两组合平均结实率为31 .11%。对31个幼胚进行愈伤组织诱导培养,其中2个形成全能性愈伤组织进而分化出再生杂种植株。细胞学观察表明,杂种胚再生植株均是染色体加倍的节节麦-大麦双二倍体(2n=28)或染色体再加倍的多倍体。节节麦-大麦双二倍体在减数分裂中期Ⅰ染色体配对平均构型为14.79Ⅰ+1.95Ⅱ+ 4.53Ⅱ′+0.01Ⅲ,表现为自交不育。杂种胚再生植株染色体数目再加倍的多倍体有少数产生了自交种子。Abstract:Hybridizations between Aegilops tauschii(2n=14)and Hordeum vulgare(2n=14)were made using Ae.tauschii as female.The mean frequency of seed set was 31.11% in two cross combinations,13 hybrid embryos were cultured for inducing callus,of which 2 produced totipotent callus,and plants were regenerated from them.These plants were Ae.tauschii-H.vulgare amphidiploids with doubling chromosome number(2n=28)and octoploids with repeatedly doubling chromosome number(2n=50~56).The Ae.tauschii-H.vulgare amphidiploids were sterile and their average chromosome pairing at MI were 14.79I+1.95II+4.53II′+0.01III.Some octoploid(2n=56)plants produced seeds after selfing.     

普通小麦与鸭茅状摩擦禾的远缘杂交 Ⅲ受精和早期胚胎的发育

用石蜡制片法和整体解剖法,对小麦品种Ｆｕｋｕｈｏ经鸭茅状摩擦禾花粉授粉后不同时间固定的子房样品进行了细胞胚胎学观察。结果表明,观察的１６８个授粉后１２０小时（５天）以内的小麦子房中有３２１％、０６％和２６２％分别发生了卵细胞单受精、极核单受精和卵细胞、极核双受精现象。发生卵细胞受精、极核受精和总受精频率分别为５８３％、２６８％和５８９％。对１１６个授粉后９天的小麦子房进行整体解剖,检测到有５００％的子房有幼胚。报道了小麦与鸭茅状摩擦禾杂交的受精过程和早期胚胎发育的情况。为小麦与鸭茅状摩擦禾杂交提供了高频率受精和胚形成的细胞胚胎学证据。     

八倍体小偃麦与普通小麦杂种F_1低育的细胞胚胎学研究

研究表明,尽管(小偃7430×烟农15)和(小偃7430×鲁麦1号)两个杂种F_1花粉母细胞减数分裂过程非常紊乱,但小孢子能正常发生,其可育花粉分别为87.95%和86.80%,能够满足传粉受精的需要。(小偃7430×烟农15)杂种F_1 91.20%的雌配子体发育正常,其中80.35%发生了正常的双受精。无论在发育正常的种子中,还是瘪小或中途停止发育的种子中,胚的分化基本能够完成,但在正常受精的子房中仅有12.10%的胚乳能正常发育。因此胚乳败育是导致八倍体小偃麦与普通小麦杂种F_1自交结实率降低的主要原因。     

节节麦细胞不同分裂时期和阶段的G—带核型及其变动性分析

采用改良的ASG法获得了中期和3个染色体凝缩程度不同的早中期阶段（分别称为早中期Ⅰ、Ⅱ、Ⅲ）染色体的G-带,并进行了G-带核型和变动性分析。所分析的分裂时期和阶段,每条染色体的全长显示出了密切邻近的多重的带纹,带纹细窄、大小较相近,带间区小,带纹分布较密集而均匀。随着有丝分裂进程推进,染色体的带纹数目减少,早中期Ⅰ、Ⅱ、Ⅲ于中期单倍染色体组的G-带带纹总数分别减少41%、36%、28%,而染色体组的绝对长度分别缩短43%、37%、27%,带数减少幅度与染色体长度缩短的幅度几乎相等。早中期Ⅰ至早中期Ⅱ、Ⅲ和早中期Ⅱ至早中期Ⅲ的带纹减少幅度与染色体长度缩短幅度也基本一致。染色体组中各染色体之间带纹减少和染色体缩短的比例不尽相同,有一定的变幅。早中期Ⅰ、Ⅱ、Ⅲ和中期染色体组中每单位绝对长度的带数（带/μm）分别为2.19、2.22、2.32和2.29,差异不大。对节节麦G-带的特性等问题进行了讨论。     

Retroelement insertional polymorphisms, diversity and phylogeography within diploid, D-genome Aegilops tauschii (Triticeae, Poaceae) sub-taxa in Iran

Background and Aims: The diploid goat grass Aegilops tauschii (2n = 2x = 14) is nativeto the Middle East and is the D-genome donor to hexaploid breadwheat. The aim of this study was to measure the diversity ofdifferent subspecies and varieties of wild Ae. tauschii collectedacross the major areas where it grows in Iran and to examinepatterns of diversity related to the taxa and geography. Methods: Inter-retroelement amplified polymorphism (IRAP) markers wereused to analyse the biodiversity of DNA from 57 accessions ofAe. tauschii from northern and central Iran, and two hexaploidwheats. Key Results: Eight IRAP primer combinations amplified a total of 171 distinctDNA fragments between 180 and 3200 bp long from the accessions,of which 169 were polymorphic. On average, about eight fragmentswere amplified with each primer combination, with more bandsbeing amplified from accessions from the north-west of the countrythan from other accessions. Conclusions: The IRAP markers showed high levels of genetic diversity. Analysisof all accessions together did not allow the allocation of individualsto taxa based on morphology, but showed a tendency to put accessionsfrom the north-west apart from others regions. It is speculatedthat this could be due to different activity of retroelementsin the different regions. Within the two taxa with most accessions,there was a range of IRAP genotypes that could be correlatedclosely with geographical origin. This supports suggestionsthat the centre of origin of the species is towards the south-eastof the Caspian Sea. IRAP is an appropriate marker system toevaluate genetic diversity and evolutionary relationships withinthe taxa, but it is too variable to define the taxa themselves,where more slowly evolving morphological, DNA sequence or chromosomalmakers may be more appropriate.     

The effect of additions ofAegilops longissima chromosomes on grain protein in common wheat

Summary The effect of various chromosomes ofAegilops longissima when added to the common wheat cultivar Chinese Spring was evaluated at two levels of nitrogen fertilization for absolute and relative amount of protein in the grain. All the added chromosomes ofAe. longissima increased protein percentage: protein increase by chromosomes D, C and A averaged 3.8% while that by chromosomes F, E, G and B averaged 1.7%. Addition lines F, D and C had a significantly higher protein weight per grain. On the other hand, lines A, E and G had reduced grain protein weight per grain as compared with that of Chinese Spring. Line C carries the HMW glutenin and some of the gliadin subunits ofAe. longissima. The effect of this line, however, and obviously that of the other lines on protein content was through genes controlling the level of storage protein rather than through genes that code directly for these proteins. Nitrogen fertilization affected protein content and the relative amount of the various protein fractions in a similar manner in every addition line. When high levels of nitrogen fertilization were compared to low ones, the relative amount of the HMW glutenins remained constant while that of HMW gliadins increased and that of the LMW subunits decreased. In contrast to the nitrogen effect, increase in protein content by the addition oflongissima chromosomes did not change the relative amounts of the various protein fractions.The paper is based on a portion of a dissertation to be submitted by A.A.L. in partial fulfillment of the PhD requirements in the Feinberg Graduate School, The Weizmann Institute of Science, RehovotThe Marshall and Edith Korshak Professor of Plant Cytogenetics     

普通小麦与钩刺山羊草杂交F1的农艺性状及细胞遗传学的观察

为有效地利用钩刺山羊草（Ａｅｇｉｌｏｐｓ ｔｒｉｕｎｃｉａｌｉｓ Ｌ．）的抗白粉病基因对小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）进行遗传改良,了解两者杂交后杂种Ｆ１的遗传机制是十分必要的。对Ｆ１杂种的研究表明,二价体频率高于理论值,是分别存在于钩刺山羊草Ｃ和Ｕ基因组中的小麦５Ｂ染色体上Ｐｈ基因抑制因子联合作用的结果。以尾状山羊草（Ａｅｇｉｌｏｐｓ ｃａｕｄａｔａ Ｌ．）Ｃ基因组特异重复序列