小麦-簇毛麦染色体代换系、易位系Ⅴ染色体RAPD标记筛选

利用105条S系列和100条Operon随机引物,对小麦一簇毛麦代换系(6V／6A)、两个易位系(6VS／6AL,6VS／6DL)及亲本簇毛麦(VV)、硬粒小麦(AABB)、栽培小麦(AABBDD)的多态性进行了筛选分析。80．95％的S系列引物扩增出了结果,且条带较清晰;在100条OP系列引物中均扩增出结果,条带清晰可见。从205个随机引物中发现,只有1个引物OPW03在含有簇毛麦V染色体的4个材料中均扩增出l条约570bp的谱带,而在栽培小麦和硬粒小麦中没有发现。因此,可以推测这个分子标记(OPW03—570)是位于簇毛麦V染色体短臂上的。     

簇毛麦1V染色体SSR标记的筛选

选用位于普通小麦1A、1B、1D染色体上的32对微卫星引物对普通小麦中国春、簇毛麦、6个中国春-簇毛麦二体附加系和1个普通小麦-簇毛麦二体代换系进行SSR分析,发现引物Xgwm498在簇毛麦中扩增出2条长分别为110 bp和190 bp的片段（即Xgwm498/110和Xgwm498/190）, 这两个片段仅在簇毛麦、中国春-簇毛麦1Ha附加系中出现,其余2Ha、     

硬粒小麦4D单体附加系的选育和利用

以显性核不育中国春小麦(AABBDD)为母本,硬粒小麦品种墨西卡利75(AABB)为轮回父本,每代选携带不育基因的不育株回交。回交高代(BC₃)对不育株做细胞学观察,从中选出具有14个二价体和一个单价     

硬粒小麦-长穗偃麦草附加系、代换系和易位系的创制

通过小麦与长穗偃麦草远缘杂交创制附加系、代换系及易位系是小麦遗传改良中利用长穗偃麦草优良基因的重要途径。本研究将长穗偃麦草特异分子标记、染色体计数、基因组原位杂交(GISH)及非变性原位杂交(ND-FISH)等多种方法相结合,对硬粒小麦Langdon (AABB)与小偃麦8801 (AABBEE)的杂交后代群体进行分子细胞学鉴定,创制出硬粒小麦-长穗偃麦草3E、6E染色体双体附加系Du-DA3E和Du-DA6E,硬粒小麦-长穗偃麦草1E (1B)染色体双体代换系Du-DS1E(1B)以及硬粒小麦-长穗偃麦草1AS-1EL染色体易位系Du-T1AS·1EL。创制的4个种质中长穗偃麦草染色体均能稳定遗传,这不仅增加了硬粒小麦-长穗偃麦草附加系和代换系的类型,还为后续利用长穂偃麦草优良基因改良小麦提供了特殊种质资源。     

基于EST-PCR的簇毛麦染色体特异分子标记筛选及应用

为定位、转移和利用簇毛麦有益基因, 通过花粉辐射, 获得一批包括小麦-簇毛麦易位染色体的异染色体系。为了鉴定这批材料中的簇毛麦染色体身份, 根据水稻、小麦的EST序列合成了240对STS引物, 其中34对引物在普通小麦中国春与簇毛麦间存在多态性;进一步对亲本及簇毛麦二体异附加系进行PCR扩增分析, 标记CINAU32_-300可追踪簇毛麦1V染色体, 标记CINAU33_-280、CINAU34_-510、CINAU35_-1100、CINAU36_-380和CINAU37_-400可追踪簇毛麦2V染色体, 标记CINAU38_-250可追踪簇毛麦3V染色体, 标记CINAU39_-950和CINAU40_-800可追踪簇毛麦4V染色体, 标记CINAU41_-745和CINAU42_-1050可追踪簇毛麦5V染色体, 标记CINAU44_-765和CINAU45_-495可追踪簇毛麦7V染色体。加上本室已开发的2个6V染色体特异标记, 用这些簇毛麦特异分子标记鉴定辐射诱导材料的部分回交后代, 选育出小麦背景中只包含单条簇毛麦染色体的整套1V至7V染色体系, 同时有18条易位染色体的簇毛麦身份得到确定, 表明这些标记可以用来快速检测普通小麦背景中的簇毛麦染色体或染色体片段。     

簇毛麦染色体对小麦生理指标的影响

研究了扬麦158、硬簇麦以及小麦-簇毛麦异染色体系DA1V、DS2V、DA3V、DA4V、DS4V、DA5V、DS6V、DA6V、DA7V等11个材料的苗期耐盐性和扬花期的光合生理特性,为进一步挖掘簇毛麦优质资源,服务小麦育种提供理论依据.11个材料在四叶期分别用浓度为100,150,200,250 mmol/L的NaCl溶液处理,进行了相对电导率的测试.在扬花期进行了气孔导度、胞间CO2浓度和净光合速率的测定.结果表明:高浓度盐胁迫(250 mmol/L NaCl)下,簇毛麦2V、3V和7V染色体能有效缓解盐胁迫对小麦的危害;簇毛麦3V染色体对不同浓度盐胁迫均表现耐盐性,3V染色体上可能携有耐盐基因;簇毛麦2V、5V、7V染色体上可能携有高光效基因,DS2V、DA5V和DA7V可作为培育高光效小麦的育种材料.     

硬粒小麦—簇毛麦双二倍体

从(T.durum×H.villosa)F₁的自交和自由授粉后代中,获得了兼具硬粒小麦穗形和簇毛麦护颖颖脊刚毛、叶片和叶鞘边缘茸毛和对白粉病免疫等双亲性状的结实性正常的植株。经细胞学鉴定,其2n=42,在花粉母细胞减数分裂中期 I(MI)有20.5个二价体,1个左右单价体,在80%左右的花粉母细胞中有21个二价体,对其自交后代连续3年、5个世代的鉴定结果表明,上述性状已基本稳定。用染色体 N——分带技术进行带型分析的结果证明,它是一个包含有硬粒小麦 A、B 染色体组和簇毛麦 V 染色体组的硬粒小麦——簇毛麦双二倍体 AABBVV.该双二倍体株高100—110厘米,穗长9—12厘米,每穗有20—24个小穗,每穗30粒左右,千粒重25—35克,籽粒蛋白质含量20%左右,对白粉病免疫,抗锈病,感染赤霉病。将它与普通小麦(T.aestivum)杂交,F₁植株的花粉母细胞在 MI 有14个左右二价体和14个左右单价体,自交结实率仅3%左右。但用普通小麦回交,结实率可逐代提高。在回交后代群体中,已分离出对白粉病免疫的植株,是一个可望在小麦育种计划中利用的新中间型材料。     

小麦属各个种简介(二)

硬粒小麦(T.durum Desf) 又称通心粉小麦,是四倍体裸粒栽培小麦。体细胞染色体数28,染色体组型AABB。分布区很广,世界五大洲均有栽培(栽培的面积仅次于普通小麦),但主要在地中海沿岸各国以及苏联、美国、加拿大等国。我国五十年代曾在西北、华北和西南部分省(区)     

一个带有杂种致死基因的普通小麦种质鲁资357

小麦杂种致死是杂种植株发育过程中发生的一种遗传紊乱现象.这种现象主要是小麦本身存在的杂种致死基因互补的作用,或者是远缘杂交导致的基因缺失或突变而造成的.杂种致死基因在很多小麦品种中多有分布,只是常常单独存在而不表达.在我国的小麦品种里杂种致死基因分布的研究只在20世纪70年代初期有极少量报道,但是对于近期培育的小麦品种和种质,有关杂种致死基因的研究报道很少.带有杂种致死基因的报道比较少.作者在用普通小麦(Triticum aestivum L.)与硬粒小麦-簇毛麦双二倍体(T.Durum-Dasypyrum villosum amphidiploid)杂交创造小麦新种质的研究中,发现一个普通小麦品系鲁资357与硬粒小麦-簇毛麦双二倍体杂种,无论是实生苗还是幼胚培养的再生植株都出现杂种致死现象.现将研究结果报道如下.     

普通小麦贵紫麦1号染色体的FISH核型分析

采用FISH(荧光原位杂交)技术,分析普通小麦贵紫麦1号染色体的FISH核型特点,为贵紫麦1号在小麦新品种选育上的应用提供参考。结果表明,贵紫麦1号包括21对染色体,pAs 1红色探针信号主要分布在A组和D组染色体上,pSc 119.2-1绿色探针信号则主要分布在B组染色体上;根据贵紫麦1号染色体上这2种探针的分布特征,可以准确辨识每条染色体。贵紫麦1号与硬粒小麦(AABB)在2A、5A、2B、3B及5B染色体上表现出pSc 119.2-1信号分布差异,与节节麦(DD)在染色体1D、4D及5D上也存在信号分布差异,与中国春(AABBDD)在2A、5A、6B、1D及7D染色体上的信号也各有不同,说明DNA重复序列在不同小麦材料之间具有多态性。     

干旱胁迫对小麦染色体代换系旗叶相对含水量和离体失水速率的影响

以中国春-Synthetic 6x小麦染色体代换系及其亲本为材料,对其旗叶相对含水量(RWC)、离体叶片失水速率(RWL)进行测定。结果表明,在干旱胁迫下,1A,2D和3D代换系叶片的相对含水量及其干旱/对照值显著或极显著高于中国春,3A,3B,4B,5B,6B,1D,2D和4D代换系叶片离体失水速率及其干旱/对照值显著或极显著低于中国春。由此表明,Synthetic 6x的1A,2D和3D染色体上可能存在干旱胁迫下调控相对含水量的基因,Synthetic 6x的3A,3B,4B,5B,6B,1D,2D和4D染色体上可能存在干旱胁迫下调控离体失水速率的基因。     

干旱胁迫对小麦叶片细胞膜透性效应的染色体定位研究

通过测定干旱胁迫下小麦中国春-Synthetic 6x染色体代换系及其亲本品种中国春(受体)和Synthetic 6x(供体)叶片的相对电导率和K 相对渗出率,对调控干旱胁迫下功能叶片细胞膜稳定性的染色体进行了定位研究。结果表明,1D,2D,2B,3A,3D,4A,4B,6A,6B,7D和7A等染色体代换系的相对电导率和K 相对渗出率均显著或极显著低于中国春,而其他代换系差异均不显著。表明Synthetic 6x的1D,2B,2D,3A,3D,4A,4B,6A,6B,7D和7A染色体上具有耐旱性基因,而其他染色体与Synthetic 6x的耐旱性无关。研究结果可为小麦抗旱遗传育种研究提供参考依据。     

九个中国北部普通小麦品种T.aestivum同源转化群5单体单价体在减数分裂后期Ⅰ时的错分裂

首次对中国北部品种同源转化群5单体单价体错分裂及单双极分布进行了研究。单体5A、5B 和5D 减数分裂后期Ⅰ错分裂频率分别为14.2%、9.2%和9.1%。中国春5A 具有最高错分裂频率(40.0%)。单体染色体或它们的错分裂产物的单极分布频率从18.6%到36.7%。双极分布频率比单极分布频率高,并随错分裂产物的增加而增加。一次、二次、三次错分裂频率差异很大。与欧、美品种相比中国北部品种同源转化群5错分裂行为与日本品种更相似。     

干旱胁迫下小麦脯氨酸积累相关基因的染色体定位

对于旱胁迫和对照条件下中国春-Hope代换系和中国春-长穗偃麦草代换系的叶片脯氨酸含量进行了测定，通过方差分析表明：普通小麦可能在4B、5A和5D染色体上有控制干旱胁迫下脯氨酸积累的基因存在，6B和6D染色体上可能有抑制脯氨酸积累的基因存在。在测定中国春-长穗偃麦草代换系的叶片脯氨酸含量后，确定小麦5A和5D染色体上有     

Chromosomal Assignment of Three Enzyme Coding Loci (Icd1, Nad-Mdh1 and Aco1) Using Primary Trisomics in Beet (Beta vulgaris L.)

Resistance to Septoria nodorum was investigated in seedlings of an amphiploid generated from Triticum dicoccum Shübl. and Aegilops squarrosa Tausch, and in a series of substitution lines of single chromosomes from this synthetic hexaploid into Triticum aestivum cv. ‘Chinese Spring’ in three tests to determine the chromosomal location of resistance. From the Ae. squarrosa parent (D genome), chromosome 5D was found to confer a high level of resistance, reducing lesion cover to near that of the amphiploid in the three tests. Chromosomes 3D, and to a lesser extent, 7D were also found to confer significant resistance to the amphiploid. Three chromosomes, 2A, 3B and 5A, from the T. dicoccum parent (AB genomes) also conferred resistance but to a lesser extent than 7D. Two chromosomes, 2B and 2D, caused a significant decrease in resistance. ‘Chinese Spring’ may thus carry genes for resistance to S. nodorum on these chromosomes which are absent in the synthetic hexaploid.     

Chromosomal location of genes affecting tissue-culture response in wheat

Six ‘Chinese Spring/Triticum spelta’ substitution lines for chromosomes 1A, 1D (duplicates), 3D (duplicates), 6D, and one ‘Chinese Spring/ Marquis’ substitution line for chromosome 2B were studied for tissue-culture response (TCR). The results reported here indicate that chromosomes 2B and 6D are critical for TCR, whereas chromosome ID affects callus weight only. Chromosomes 1A and 3D were not found to be critical, however, these chromosomes may carry genes with minor effects.     

Frost resistance of 'Chinese Spring'/'Cheyenne' chromosome substitution lines under short- and long-day hardening conditions

Investigations were carried out under phytotronic conditions to study the effect of daylength on the frost resistance of a ‘Chinese Spring’/‘Cheyenne’ chromosome substitution series. The frost resistance of the 5A, 7A, 4B, 5B, 1D and 5D lines was significantly better when raised and hardened with long-day (16 h) rather than short-day (8h) illumination. The frost resistance-increasing effect of daylength could be demonstrated after freezing lines 5A and 5D at both - 10°C and -12°C. An increase in the duration of illumination in the course of preliminary growth and hardening promoted the development of a higher level of frost resistance. This positive effect was most pronounced for chromosome substitution lines, where the frost resistance was significantly better than that of ‘Chinese Spring’ even with normal daylengths.     

Chromosome location of genes affecting polyphenol oxidase activity in seeds of common and durum wheat

This study used cytogenetic stocks to investigate the chromosomal location of genes responsible for polyphenol oxidase (PPO) activity in common and durum wheat seeds. Substitution lines of chromosome 2A of hexaploid varieties ‘Cheyenne’, ‘Thatcher’ and ‘Timstein’ in ‘Chinese Spring’ showed significantly higher PPO activity than all other substitution lines of the same variety, with the exception of substitutions of ‘Cheyenne’ chromosome 3A and ‘Thatcher’ chromosome 4B. Substitution lines of chromosome 2A of Triticum turgidum var. dicoccoides and of chromosome 2D of ‘Chinese Spring’ into the tetraploid variety ‘Langdon’ showed a significant increase in PPO activity relative to all other substitution lines in Langdon. The gene(s) responsible for high PPO activity in chromosome 2D from ‘Chinese Spring’ was mapped on the long arm within a deletion that represents 24% of the distal part of the arm. This study shows that genes located in homoeologous group 2 play a major role in the activity of PPO in wheat.     

Involvement of Chromosomes 5A and 5D in Cold-Induced Abscisic Acid Accumulation in and Frost Tolerance of Wheat Calli

The relationship between frost tolerance and abscisic acid (ABA) accumulation was studied in callus cultures of three wheat cultivars differing in the level of frost-tolerance, and of the 5A and 5D chromosome substitution lines from the frost-tolerant variety ‘Cheyenne’ into frost-sensitive ‘Chinese Spring’. Following cold hardening, the increase in ABA level in the calli of the two frost tolerant cultivars was significantly higher than in those of the frost-susceptible cultivar. Similarly, in 5A and 5D substitution lines, significantly higher ABA levels were detected than in the recipient ‘Chinese Spring’. One week-long ABA treatment at 26 °C induced a significantly higher level of frost tolerance than that achieved by cold hardening, irrespective of the frost sensitivity of the examined genotypes.     

Temperature as a component of the expression of developmental responses in wheat

Summary Studies were made of days to ear emergence under the constant temperatures of 9, 14, 19 and 25°C and 16 h photoperiod in three sets of wheat lines each possessing genotypes differing for developmental responses.Days to ear emergence in three near-isogenic lines of the wheat cultivar Triple Dirk, which differed for vernalization response, increased as the strength of the response increased. At the four temperatures Triple Dirk D (Vrn 1 vrn 2) was not significantly different from normal Triple Dirk (Vrn 1 Vrn 2) but Triple Dirk B (vrn 1 Vrn 2) was significantly (P=0.01) later than normal Triple Dirk at each temperature. This indicates that the vrn 1 allele confers stronger vernalization response than vrn 2 over the range of temperatures (9–24°C). However, Triple Dirk C (vrn 1 vrn 2) failed to head after 120 days at each temperature indicating strong interaction between vrn 1 and vrn 2 with each other (and possibly the Triple Dirk back-ground) to give a much stronger vernalization response than predictions from additivity of their individual effects.The second set comprised the four Chinese Spring/Thatcher chromosome substitution lines CS/T 3B, 6B, 7B and 5D, plus Chinese Spring and Thatcher, and were grown in the unvernalized condition. CS/T 5D was similar in days to ear emergence as Chinese Spring at all four temperatures but the other three lines were earlier to ear emergence, particularly as the temperature increased. Days to ear emergence was fastest at 14°C in all lines, except CS/T 3B, in which it decreased progressively from 9 to 24°C.The third set of Chinese Spring and Thatcher and the homoeologous group 2 chromosomes of Thatcher substituted in Chinese Spring, the group which is considered to be involved in the control of photoperiod sensitivity. The three substitution lines responded differently to temperature compared with Chinese Spring and with each other, with chromosome 2D being the least, and chromosome 2B the most, responsive to temperature.