偃麦草与小偃麦染色体组构成的细胞遗传学研究在Ⅴ.硬粒小麦与中间偃麦草杂交及回交的细胞遗传学研究

获得了硬粒小麦(2n=6x=28、AABB)与中间偃麦草(2n=6x=42、NNE_1E_1E_2E_2)杂种F_1及回交后代材料。统计分析杂种F_1及回交一代PMC MI染色体配对构型,认为中间偃麦草具较远缘的同亲关系(distant homologous)染色体组。由三价体出现频率分析,中间偃麦草不含小麦的B染色体组,建议用NE_1E_2为其染色体组公式。根据回交一代及其自交后代染色体数目,分析了六倍体小偃麦这一人工新物种的形成过程。     

硬粒小麦×天蓝偃麦草属间杂种无性系的建立

本实验以“人民麦”ד天蓝偃麦草”F_0成熟胚、F_1幼穗及“珂珂瑞特”ד天蓝偃麦草”F_1幼穗为外植体,在MS+2mg/L2,4-D的培养基上诱导愈伤组织,在无激素的MS培养基上诱导再生植株。产生胚性愈伤组织的频率最高为78.9％。植株再生方式为体细胞胚胎发生方式,再生频率最高为100％。胚性愈伤组织经13个月的继代培养仍具再生能力。发现一种特殊分化现象,即小花结构的分化,并对产生这种现象的原因进行了分析。     

硬粒小麦×蓝偃麦草属间杂种无性系的建立

本实验以“人民麦”ד天蓝偃麦草”成熟胚幼穗及“珂珂瑞特”ד天蓝偃麦草”F₁幼穗为外植体,在MS+2mg/L2,4-D的培养基上诱导愈伤组织,在无激素的MS培养基上诱导再生植株。产生胚性愈伤组织的频率最高为78.9%。植株再生方式为体细胞胚胎发生方式,再生频率最高为100%。胚性愈伤组织经13个月的继代培养仍具再生能力。发现一种特殊分化现象,既小花结构的分化,并对产生这种现象的原因进行了分析。     

普通小麦与东方旱麦草属间杂种的形态和细胞遗传学研究

本文对普通小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．ｅｖ．Ｆｕｋｕｈｏ,２ｎ＝６ｘ＝４２,ＡＡＢＢＤＤ）与东方旱麦草（Ｅｒｅｍｏｐｙｒｕｍｏｒｉｅｎｔａｌｅ（Ｌ．）Ｊａｕｂ．ｅｔＳｐａｃｈ,２ｎ＝４ｘ＝２８,Ｂ′Ｂ′Ｃ′Ｃ′）属间杂种Ｆ_１进行了形态和细胞遗传学方面的探讨。首先,在形态方面的研究表明：（１）杂种Ｆ_１植株生长旺盛,分蘖力强;（２）绝大部分性状如株高、穗长、芒长等介于双亲之间而呈中间型,少数性状如颖脊、颖壳茸毛可作为鉴别杂种的形态标记;（３）花粉粒空秕、无可染性,花粉高度不育,自交完全不结实。其次,从杂种Ｆ_１的细胞遗传学研究表明：（１）染色体平均构型为：２６．０９Ⅰ＋４．３６Ⅱ＋０．０９Ⅲ,二价体数目从０－７个均有分布,但大多数为棒状二价体;（２）每细胞平均交叉数为４．７８;（３）染色体臂平均配对频率（Ｃ值）为０．１７。由上可知,在普通小麦ＡＢＤ基因组与东方旱麦草Ｂ′Ｃ′基因组之间存在微弱的部分同源关系,或在东方旱麦草基因组中可能存在一种抑制普通小麦Ｐｈ基因作用的抑制因子（ｓｕｐｐｒｅｓｓｏｒ）。     

硬粒小麦 长穗偃麦草2E和4E附加系及E染色体传递

为探讨长穗偃麦草E染色体在硬粒小麦背景中的传递特点,利用染色体特异分子标记、基因组原位杂交(GISH)、非变性荧光原位杂交(ND FISH)等方法,对小偃麦8801(AABBEE)与硬粒小麦(AABB)杂交后代中选育的株系Du_No.2和Du_No.4进行了分析。结果表明：(1)分子标记检测株系Du_No.2及Du_No.4分别能扩增出长穗偃麦草2E、4E染色体特异条带。(2)GISH和ND FISH分析显示,株系Du_No.2和Du_No.4分别附加了1条2E和4E染色体,表明株系Du_No.2 和Du_No.4分别为硬粒小麦 长穗偃麦草2E和4E单体附加系。(3)2个株系的减数分裂过程观察发现,后期Ⅰ、Ⅱ和末期Ⅱ都有E染色体分离异常现象,且株系Du_No.2和 Du_No.4的异常率分别为22.24%和36.18%。(4)2个株系分别与硬粒小麦进行正反杂交的后代PCR分析表明, 2E和4E染色体经雄配子的传递率分别为4.41%和2.17%,而通过雌配子的传递率都为零,表明2E和4E染色体在硬粒小麦背景中能通过雄配子传递,但不通过雌配子的传递。该研究为创建全套硬粒小麦 长穗偃麦草双体附加系及代换系提供基础。     

小麦与长穗偃麦草,中间偃麦草杂种及其衍生后代的细胞遗传学研究

十倍体长穗科草和六倍体中间偃麦草均含有一些基因促使部分同源的染色体之间发生配对,这些基因分布于不同的染色体组中,并具很强的传递力。小麦与长穗偃麦草杂种回交后代的部分植株在减少数分裂后期出现多条染色同时断裂现象,使不同染色体通过断口联结形成新的易位成为可能。上述二因素可能是造成小麦和偃麦草基因重组的主要原因之一。     

偃麦草与小偃麦染色体组构成的细胞遗传学研究V.硬粒小麦与中…

获得了硬粒小麦（２ｎ＝６ｘ＝２８,ＡＡＢＢ）与中间偃麦草（２ｎ＝６ｘ＝４２,ＮＮＥ１Ｅ１Ｅ２Ｅ２）杂种Ｆ１及回交后代材料。统计分析杂种Ｆ１及回交一代ＰＭＣＭＩ染色体配对构型,认为中间偃麦草具较远缘的同亲关系染色体组。由三价体出现频率分析,中间偃麦草不含小麦的Ｂ染色体组,建议用ＮＥ１Ｅ２为其染色体组公式。根据回交一代及其自交后代染色体数目,分析了六倍体小偃麦这一人工新物种的形成过程。     

偃麦草与小偃麦染色体组构成的细胞遗传学研究Ⅱ.八倍体小偃麦与四倍体小麦杂种的减数分裂观察

在获得八倍体小偃麦“小偃7430”与二个四倍体小麦物种,硬粒小麦和提摩菲维小麦的杂种的基础上,观察了F_1的减数分裂。中期Ⅰ不仅出现许多单价体,还观察到极复杂的多价体,二个杂种平均每细胞构型分别为13.5Ⅰ+11.1Ⅱ+1.67Ⅲ+0.24Ⅳ+0.02Ⅴ+0.04Ⅵ和19.8Ⅰ+7.01Ⅱ+2.16Ⅲ+0.27Ⅳ+0.10Ⅴ+0.01Ⅵ+0.004Ⅶ。后一杂种后期Ⅰ细胞中观察到平均7.14个单价体排列于赤道板,其分裂过程显然与由交叉维系的染色体不同。对此杂种作了花药培养,得到了绿苗。讨论了以这种“8×4”杂种形成具有重建型染色体组的次级六倍体的可能性。     

偃麦草与小偃麦染色体组构成的细胞遗传学研究——Ⅱ.八倍体小偃麦与四倍体小麦杂种的减数分裂观察

在获得八倍体小偃麦“小偃7430”与二个四倍体小麦物种,硬粒小麦和提摩菲维小麦的杂种的基础上,观察了F₁的减数分裂。中期Ⅰ不仅出现许多单价体,还观察到极复杂的多价体,二个杂种平均每细胞构型分别为13.5Ⅰ+11.1Ⅱ+1.67Ⅲ+0.24Ⅳ+0.02Ⅴ+0.04Ⅵ和19.8Ⅰ+7.01Ⅱ+2.16Ⅲ+0.27Ⅳ+0.10Ⅴ+0.01Ⅵ+0.004Ⅶ。后一杂种后期Ⅰ细胞中观察到平均7.14个单价体排列于赤道板,其分裂过程显然与由交叉维系的染色体不同。对此杂种作了花药培养,得到了绿苗。讨论了以这种“8×4”杂种形成具有重建型染色体组的次级六倍体的可能性。     

普通小麦与长穗偃麦草杂种及其衍生材料的细胞遗传学特性

对十倍体长穗偃麦草(Thinopyrum ponticum)与普通小麦杂交F1及其与普通小麦回交BC1F1的形态学和细胞学特性进行了分析。结果表明,长穗偃麦草与普通小麦‘兰考矮早八’衍生F1(‘兰考小偃麦’)的根尖细胞染色体数为56条;花粉母细胞减数分裂中期Ⅰ染色体构型平均值为19.81Ⅰ+15.78Ⅱ+0.75Ⅲ+0.59Ⅳ;基因组荧光原位杂交(GISH)显示,兰考小偃麦中含有35条完整的长穗偃麦草和21条小麦染色体。‘兰考小偃麦’/‘科育818’和‘兰考小偃麦’/‘Cp02-3-5-5’杂交F1的根尖细胞染色体数及其所遗传的长穗偃麦草染色体数分别为50~52和16~22条,且存在染色体易位;花粉母细胞减数分裂中期Ⅰ平均染色体构型为14.54Ⅰ+17.40Ⅱ+0.55Ⅲ+0.14Ⅳ,平均49.4%的细胞出现多价体(三价体或四价体)。这些材料为创造小麦-长穗偃麦草新种质奠定了基础。     

大麦与小麦属间杂种的形态学和细胞遗传学研究

通过幼胚培养技术分别获得了大麦(Hordeum vulgare L., 2n=2x=14)与普通小麦(Triticum aestivum L., 2n=6x=42)、硬粒小麦(T. durum d. sf., 2n=4x=28)以及栽培二粒小麦(T. dicoccum Schrank 2n=4x=28)之间的属间杂种,平均杂交结实率分别为3.0％、1.2％和0.8％。杂种在形态上偏向小麦,自交不孕,用父本作回交亲本获得了大麦×普通小麦杂种的回交一代。所有杂种均表现细胞学上的不稳定性。杂种减数分裂中期1 PMC染色体平均配对频率和交叉结频率分别为27.31Ⅰ 0.33Ⅱ 0.011Ⅲ,0.45;20.571 0.20Ⅱ 0.008Ⅲ,0.25和20.41Ⅰ 0.28Ⅱ 0.005Ⅲ,0.32,表明双亲染色体组间不存在同源关系。大麦×四倍体小麦杂种小孢子的染色体计数表明,杂种中未减数雄配子的频率在60％以上。     

普通小麦与冰草间杂种的细胞遗传学及其自交可育性

为了进一步研究冰草属（Ａｇｒｏｐｙｒｏｎ Ｇａｅｒｔｎ．）的Ｐ染色体组与小麦染色体组间的遗传关系和评价Ｐ染色体组在属间杂种自交可育性上的遗传效应,获得了普通小麦品种Ｆｕｋｕｈｏ（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ ｃｖ．Ｆｕｋｕｈｏ,２ｎ＝４２;ＡＡＢＢＤＤ）与３个不同来源的四倍体冰草（Ａ．ｃｒｉｓｔａｔｕｍ＜Ｌ．＞Ｇａｅｒｔｎ．,２ｎ＝２８;ＰＰＰＰ）间的杂种（２ｎ＝３５;ＡＢＤＰＰ）。结果表明     

节节麦和硬粒小麦-簇毛麦双二倍体间杂种的产生及其细胞遗传学研究

通过胚培养产生了节节麦和硬粒小麦-簇毛麦双二倍体间的杂种。结果表明节节麦和硬粒小麦-簇毛麦双二倍体杂交以节节麦作母本较易结实,3个组合的结实率分别为59.18%、67.72%和60.22%,胚培成苗率分别为39.13%、38.10%和50%。杂种F_1生活力旺盛,形态像父本硬粒小麦-簇毛麦双二倍体。杂种自交可孕,3个组合自交结实率平均为7.63%。杂种F_1(ABVD)的减数分裂平均构型为25.36个单价体,1.21个二价体和0.06个三价体,平均每个细胞交叉结频率为1.38,高于“中国春”单倍体的配对频率,推测V组和A、B、D组染色体间有部分同源关系。节节麦和硬粒小麦-簇毛麦双二倍体杂交可能是产生八倍体(AABBDDVV)的又一途径。     

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。     

Elymus与普通小麦属间杂种的细胞遗传学研究

本研究以Elymus pendulinus(Nevski)Tzvelev(2n=4x=28,SSYY)、E.shandongenisis B.Salomon(2n=4x=28,SSYY)与普通小麦(Triticum aestivum L.:2n=6x=42,AABBDD)进行了属间远缘杂交。通过对杂种胚的离体培养,两个组合均产生了杂种F_1植株。杂种F_1为多年生,植株生长旺盛;形态上介于亲本种之间而兼具双亲的某些特征;穗状花序发育正常,但均完全不育。两个组合的根尖和花粉母细胞染色体数目为2n-5x=35。通过对杂种减数分裂染色体配对行为的分析,发现其MI染色体的配对水平很低,二价体均为棒状,每细胞的平均染色体交叉数在0.25-0.31之间。这表明E.pendulinus t E.shandongensis 所含的SY染色体组与普通小麦的ABD染色体之间的同源程度很低。由于在E.shandongeasis 及其它具有SY染色体组的Elymus 单倍体中,SY染色体组之间的部份同源染色体配对数均明显高于该杂种中的配对数,这表明存在于普通小麦中的ph基因及其它具类似作用的基因系统能抑制SY染色体组之间的部份同源染色体配对。     

Two-Dimensional Electrophoretic Analysis of Soluble Leaf Proteins of a Salt-sensitive （Triticum aestivum） and a Salt-tolerant （T. durum） Cultivar in Response to NaCI Stress

In this research, 3-day-old etiolated wheat seedlings of Triticum aestivum L. cv. Ceyhan-99 （salt-sensitive） and T. durum Desf. cv. Firat-93 （salt-tolerant） were grown in control and salt （150 mmol/L NaCl） treatments at a 15/25℃ temperature regime in the light for 12 days. Soluble proteins extracted from the first leaf tissues of two cultivars were analyzed by twodimensional （2-D） electrophoresis in order to detect NaCl-induced changes. The soluble leaf protein profiles of cultivars were observed to be similar. However, quantitative differences in 74 proteins were detected in the salt treatment group, compared to the control. Among the 74 protein spots, 14 were common for two cultivars. As a result of NaCl treatment, two low-molecular-weight （LMW） proteins （28.9 and 30.0 kDa） and one intermediate-molecular-weight （IMW） protein （44.3 kDa） in cv. Ceyhan-99 and six LMW proteins （18.6, 19.4, 25.7, 25.9, 26 and 27.6 kDa） in cv. Firat-93 were newly synthesized. The newly synthesized proteins were specific to each cultivar. In the Firat-93 cultivar, four proteins with LMW （24.8-27.9 kDa） were completely lost in NaCl treatment. Moreover, these four protein spots were not observed in both protein profiles of cv. Ceyhan-99. Most of these proteins were in acidic character （pl 〈6.0-6.9） and low molecular weight （〈31.6 kDa）. It is suggested that the newly synthesized or completely lost LMW proteins may be important for cultivars differing in sensitivity towards NaCl.     

Structural chromosome differentiation between Triticum timopheevii and T. turgidum and T. aestivum

 Chromosome pairing at metaphase-I was analyzed in F₁ hybrids among T. turgidum (AABB), T. aestivum (AABBDD), and T. timopheevii (A^tA^tGG) to study the chromosome structure of T. timopheevii relative to durum (T. turgidum) and bread (T. aestivum) wheats. Individual chromosomes and their arms were identified by means of C-banding. Homologous pairing between the A-genome chromosomes was similar in the three hybrid types AA^tBG, AA^tBGD, and AABBD. However, associations of B-G were less frequent than B-B. Homoeologous associations were also observed, especially in the AA^tBGD hybrids. T. timopheevii chromosomes 1A^t, 2A^t, 5A^t, 7A^t, 2G, 3G, 5G, and 6G do not differ structurally from their counterpart in the A and B genomes. Thus, these three polyploid species inherited translocation 5AL/4AL from the diploid A-genome donor. Chromosome rearrangements that occurred at the tetraploid level were different in T. turgidum and T. timopheevii. Translocation 4AL/7BS and a pericentric inversion of chromosome 4A originated only in the T. turgidum lineage. The two lines of T. timophevii studied carry four different translocations, 6A^tS/1GS, 1GS/4GS, 4GS/4A^tL, and 4A^tL/3A^tL, which most likely arose in that sequence. These structural differences support a diphyletic origin of polyploid wheats. Received: 15 June 1998 / Accepted: 19 August 1998     

Transformation of pasta wheat (Triticum turgidum L. var. durum) with high-molecular-weight glutenin subunit genes and modification of dough functionality

Particle bombardment has been used to transform three cultivars (L35, Ofanto, Svevo) and one breeding line (Latino × Lira) of durum wheat (Triticum turgidum L. var. durum). These varieties were co-transformed with plasmids containing selectable and scorable marker genes (bar and uidA) and plasmids containing one of two high-molecular-weight (HMW) glutenin subunit genes (encoding subunits 1Ax1 or 1Dx5). Ten independent transgenic lines were recovered from 1683 bombarded scutella (transformation efficiency thus 0.6%). Five lines expressed either subunit 1Dx5 or 1Ax1 at levels similar to those of endogenous subunits encoded on chromosome 1B. To identify the effects of the transgenes on the functional properties of grain, three lines showing segregation for transgene expression were used to isolate sibling T₂ plants which were null or positive for the transgene product. Analysis of these plants using a small-scale mixograph showed that expression of the additional subunits resulted in increased dough strength and stability, demonstrating that transformation can be used to modify the quality of durum wheat for bread and pasta making.     

Two-Dimensional Electrophoretic Analysis of Soluble Leaf Proteins of a Salt-sensitive(Triticum aestivum)and a Salt-tolerant(T.durum)Cultivar in Response to NaCl Stress

In this research, 3-day-old etiolated wheat seedlings of Triticum aestivum L. cv. Ceyhan-99 (salt-sensitive) and T. durumDesf. cv. Firat-93 (salt-tolerant) were grown in control and salt (150 mmol/L NaCI) treatments at a 15/25℃ temperatureregime in the light for 12 days. Soluble proteins extracted from the first leaf tissues of two cultivars were analyzed by two-dimensional (2-D) electrophoresis in order to detect NaCl-induced changes. The soluble leaf protein profiles of cultivarswere observed to be similar. However, quantitative differences in 74 proteins were detected in the salt treatment group,compared to the control. Among the 74 protein spots, 14 were common for two cultivars. As a result of NaCl treatment, twolow-molecular-weight (LMW) proteins (28.9 and 30.0 kDa) and one intermediate-molecular-weight (IMW) protein (44.3 kDa)in cv. Ceyhan-99 and six LMW proteins (18.6, 19.4, 25.7, 25.9, 26 and 27.6 kDa) in cv. Firat-93 were newly synthesized. Thenewly synthesized proteins were specific to each cultivar. In the Firat-93 cultivar, four proteins with LMW (24.8-27.9 kDa)were completely lost in NaCl treatment. Moreover, these four protein spots were not observed in both protein profiles ofcv. Ceyhan-99. Most of these proteins were in acidic character (pi<6.0-6.9) and low molecular weight (<31.6 kDa). It issuggested that the newly synthesized or completely lost LMW proteins may be important for cultivars differing in sensitivitytowards NaCl.     

Hybrids of Aegilops cylindrica Host with Triticum durum Desf. and T. aestivum L

The hybrids of durum and bread wheat with Ae. cylindrica have been obtained without using an embryo rescue technique. The hybrid output (of pollinated flower number) in the field conditions scored 1.0, 15.3 and 10.0% in the crosses T. durum x Ae. cylindrica, Ae. cylindrica x T. durum and T. aestivum x Ae. cylindrica, respectively. A high level of meiotic chromosome pairing between homologous D genomes of bread wheat and Aegilops has been revealed (c = 80.0-83.7%). The possibility of homoeological pairing between wheat and Ae. cylindrica chromosomes has been shown. Herewith, the correlation between the levels of homological and homoeological pairing is absent. The possibilities of genetic material interchange, including between the tetraploid species, as well as the using of Ae. cylindrica cytoplasm for durum wheat breeding are discussed.