Genetic Variation in Triticum turgidum L.ssp.turgidum Landraces from China Assessed by EST-SSR Markers

It was helpful for the wheat improvement to evaluate the genetic resources of Triticum turgidum L. ssp. turgidum landraces. In this study, 68 turgidum landraces accessions, belonging to four geographic populations in China, were investigated by using EST-SSR markers. A total of 63 alleles were detected on 22 EST-SSR loci, and the number of alleles on each locus ranged from 1 to 5, with an average of 2.9. The results of the analysis of molecular variance （AMOVA） indicated that 92.5% of the total variations was attributed to the genetic variations within population, whereas only 7.5% variations among populations. Although the four populations had similar genetic diversity parameters, Sichuan population was yet distinguished from other populations when comparing the population samples in pairs. Significant correlations were detected by the statistic analysis among six genetic diversity parameters among each other. The selection difference between heterozygosty and homozygosty was also observed among different EST-SSR locus. The genetic similarity （GS） ranged from 0.18 to 0.98, with the mean of 0.72, and all accessions could be clustered into 7 groups. The dendrogram suggested that the genetic relationships among turgidum accessions evaluated by EST-SSR markers were unrelated to their geographic distributions. These results implied that turgidum landraces from China had the unique characters of genetic diversity.     

圆锥小麦ramosa2的克隆及其重组蛋白的DNA结合特性分析

 【目的】从四倍体圆锥小麦中克隆ramosa2(TtRa2),分析其序列特征、组织表达特异性和体外活性,为阐明ramosa2与麦类作物穗形态建成关系奠定基础。【方法】利用半定量RT-PCR分析ramosa2在不同组织中的表达水平,将其重组到pET-21a-MBP载体并在T7 Express菌株中诱导表达。利用Amylose亲和层析柱纯化重组蛋白,通过凝胶阻滞试验对其DNA特异结合能力进行鉴定。【结果】TtRA2含有LOB和RA2结构域,属于Ⅰ类LBD蛋白家族成员。TtRa2在幼穗中高丰度表达,而在根、茎、叶、种子中未检测到表达。融合的TtRA2主要以可溶性形式存在,其表达量占总蛋白的68.6%。重组TtRA2可与包含核心序列“GCGGCG”的DNA探针特异性结合,两者形成的复合体的解离常数约为10 nmol?L-1。【结论】TtRa2参与圆锥小麦穗形态建成,其编码产物具备RA2-like转录因子的典型特征,具有类似拟南芥LOB的DNA结合特性。     

Molecular Characterization of Atlas 66-Derived Wheat Near-lsogenic Lines Contrasting in Aluminum （Al） Tolerance

Aluminum （Al） toxicity is the major limiting factor for wheat growth in acidic soils. Genetic improvement of Al tolerance is one of the most cost-effective solutions to improve wheat productivity. The objective of this study was to characterize near isogenic lines （NILs） contrasting in Al tolerance derived from Atlas 66 in the backgrounds of Al-sensitive cultivars Chisholm and Century using amplified fragment length polymorphism （AFLP） and simple sequence repeat （SSR）. A total of 200 AFLP and 88 SSR primer pairs were screened and 12 markers （11 AFLPs and one SSR） were associated with Al-tolerance in NILs of at least one recurrent parental background. Among them, nine were linked to A1 tolerance in the Chisholm-derived NILs, seven were associated with Al-tolerance in the Century-derived NILs, and three AFLPs derived from the primer combinations of pAG/mGCAG, pCAG/mAGC and pGTG/mGCG, and one SSR, Xwmc331 on chromosome 4D, associated with A1 tolerance in NILs of both recurrent parental backgrounds. Those common markers across two backgrounds may be the major marker loci associated with Al-tolerance in Atlas 66 and could be useful for marker-assisted breeding to improve Al tolerance in wheat. In addition, evaluation of Al tolerance among different genotypes using hematoxylin stain and relative root growth revealed that Atlas 66 was more tolerant to Al stress than the NILs, therefore suggested that the Al-tolerant NILs might not carry all Al-tolerance loci from Arias 66 and inheritance of Al tolerance in Arias 66 is more likely multigenic.     

小麦春化相关基因研究进展

小麦（Triticum aestivum L.）是世界第二大粮食作物。春化作用是冬小麦成花必需过程,该过程同时伴随低温驯化,影响着小麦品种种植范围及产量。简要概述目前克隆的小麦春化相关基因及春化作用调控机理等研究进展,为小麦春化作用机理研究提供资料。     

斯卑尔脱小麦品质性状分析

对142份斯卑尔脱小麦材料进行了品质性状测定与分析。结果表明,被测性状存在较大的遗传变异,绝大多数材料为软质和角质;平均蛋白质含量16.06%,104份材料的湿面筋含量>28%,达到中筋小麦标准。56.82%材料的沉降值大于50 mL;面团吸水率>70%的材料有73份,形成时间大于7.5 min的材料有3份;筛选到蛋白含量>20%的材料3份,高沉降值(>75 mL)材料10份。6份品质性状且农艺性状均较好的斯卑尔脱小麦可望用于普通小麦品质遗传改良。     

QTL Mapping for Drought Tolerance at Stages of Germination and Seedling in Wheat (Triticum aestivum L.)Using a DH Population

Drought is a major constraint in many wheat(Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in a double haploid (DH) population derived from the cross, Hanxuan10×Lumai14, using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Interval mapping analysis revealed that QTLs for drought tolerance at germination stage were located on chromosomes 1B, 2B, 5A, 6B, 7A and 7B, respectively, and the most effective QTL was mapped on chromosome 2B, explaining 27.2% of phenotypic variance. The QTLs for drought tolerance at seedling stage were located on 1B, 3B and 7B, respectively, and the most effective QTL was mapped on chromosome 3B, explaining 21.6% of phenotypic variance. Their positions were different from those of QTLs conferring drought tolerance at germination stage, indicating that drought tolerance at germination stage and seedling stage was controlled by different loci. Most of the identified QTLs explained 18% or more of phenotypic variance for drought tolerance at germination and seedling stage, and would be useful in future for marker assisted selection programs and cultivar improvement.     

斯卑尔脱小麦主要农艺性状鉴定与评价

为进一步拓宽小麦育种基因资源,对来自18个国家和地区的151份斯卑尔脱小麦的主要农艺性状进行了考察与分析。结果表明,供试材料总体植株偏高,分蘖力强,小穗数多,千粒重偏低,成穗率较高,生育期较长等特点。相关分析发现有效穗与分蘖数、成穗率,穗粒数与小穗数、千粒重、株高成正偏相关极显著,抽穗期与穗长正偏相关显著。千粒重与穗长、小穗数和穗粒重等多个性状存在复杂的相关关系。主成分分析显示5个主成分可提供85.13%的信息量,其中以粒重因子的贡献率最高(24.68%)。供试材料基于农艺性状可被聚为三类,类Ⅰ和类Ⅲ分别为矮杆晚熟型和高杆穗数型,类Ⅱ又可分为高杆晚熟型、早熟粒重型、短穗粒重型和穗数粒重型四个亚类,聚类结果与其地理来源有一定的相关性,但不完全一致。     

耐酸耐铝毒苜蓿根瘤菌的筛选

从紫花苜蓿、天蓝苜蓿和南苜蓿植株上分离获得的22株根瘤菌菌株中筛选出5株耐酸较好的苜蓿根瘤菌菌株,分别为S0710、S0713、L0701、L0702和P0701,这5株菌株在pH值5的酸性条件下仍能正常生长,茼株S0713和P0701甚至能在pH值4的酸性条件下生长.酸性条件下菌株L0701和P0701对AI3+有较好的耐受性.而菌株S0710则对AI3+极为敏感.     

水杨酸对提高小麦抗盐效应的研究

本文以盐敏感品种中国春、农大85021和抗盐品种冬68、茶淀红等4个品种小麦(Triticum aestivum L.)为材料,研究盐分胁迫对小麦种子萌发和幼苗生长的影响以及水杨酸对盐害的缓解作用.结果表明,水杨酸能够相对提高盐分胁迫条件下小麦种子萌发的数量、速度和质量;提高幼苗体内游离脯氨酸、可溶性糖等渗透调节物质的含量,增强其渗透调节能力,同时提高幼苗体内超氧化物歧化酶、过氧化物酶等细胞保护酶的活性,抑制膜脂过氧化作用产物丙二醛的积累,降低叶片质膜透性和盐分胁迫对细胞膜的伤害.所有这些变化都有利于缓解盐害、提高小麦抗盐性     

不同耐盐性高粱在盐逆境下的比较转录组分析

【目的】土壤盐渍化是制约作物生产的重要非生物胁迫因子之一,高粱耐盐性强,进行高粱耐盐基因挖掘及分子机制研究是开发和利用盐渍土壤的有效途径,通过转录组测序分析与高粱耐盐相关的基因调控机制和代谢通路,挖掘高粱耐盐潜力。【方法】 通过以筛选出的极耐盐品种八叶齐和盐极敏感品种PL212为试验材料,采用盆栽沙培,在播种后20 d（5叶期）采用180 mmol·L ^-1的 NaCl 溶液漫灌模拟盐逆境,盐胁迫48 h后取幼叶,并连同对照（未经过盐处理）的同期幼苗共4个样品提取RNA,进行转录组测序,采用qRT-PCR方法对测序结果进行验证。 【结果】 耐盐和盐敏感材料分别在盐渍和非盐渍处理下的4个样品间共检测到1 338个差异表达基因,包括819个上调基因和519个下调基因。聚类分析发现在应答盐渍胁迫逆境时,5个依赖性氧合酶超家族蛋白、4个富含半胱氨酸的激酶、3个谷胱甘肽S-转移酶和3个重金属运输/解毒超家族蛋白相关基因表现出明显的上调表达和下调表达,还发现1个K ⁺转运蛋白基因在耐盐调节中起着重要作用。GO分析发现在15 418个基因中获得4 528个有效GO注释条目,同时耐盐和盐敏感材料在遭受盐逆境时的生物过程、细胞组分和分子功能3个方面均存在较大差异。生物过程中代谢过程、细胞过程耐盐材料明显高于盐敏感材料,耐盐材料的生理过程中较盐敏感材料增加了多生物过程和定位这两个过程,很可能与耐盐材料盐抗性较强密切相关。差异基因KEGG分析结果显示耐盐和盐敏感材料在对照和盐渍胁迫条件下的苯丙烷类生物合成、苯丙氨酸代谢、类黄酮生物合成3个途径中差异基因表达较多,可能是造成耐盐和盐敏感材料耐盐性差异较大的重要原因。 【结论】 高粱耐盐调控基因表达涉及生物过程、细胞组分和分子功能多个方面,生物过程和定位这两个过程是提高高粱耐盐性的关键;苯丙烷类生物合成、苯丙氨酸代谢、类黄酮生物合成3个途径的基因表达很可能是造成盐害的重要原因。     

病原诱导的小麦转录因子TaERF1b基因的分离和表达

 【目的】研究一个病原诱导的小麦ERF转录因子基因在对纹枯病菌、赤霉病菌防御反应中的作用。【方法】应用生物信息学、RT-PCR、RACE方法,从赤霉病菌诱导的小麦中,分离ERF转录因子基因的全长cDNA序列;利用半定量RT-PCR方法,分析该基因对小麦纹枯病菌、赤霉病菌及MeJA、ET和SA处理的应答表达情况。【结果】从赤霉病菌诱导的抗赤霉病小麦品种苏麦3号cDNA中,分离出1个编码ERF转录因子基因的全长cDNA序列。该基因暂被命名为TaERF1b,编码由280个氨基酸组成的蛋白质TaERF1b。TaERF1b具有保守的ERF/AP2结构域,但TaERF1b蛋白全长氨基酸序列与已克隆的ERF蛋白同源性较低（＜36.5%）。TaERF1b基因表达分析的结果表明,纹枯病菌、赤霉病菌侵染可快速诱导抗病小麦中TaERF1b基因的上调表达,该基因转录表达水平在防卫相关激素乙烯、茉莉酸处理早期显著增强,而且TaERF1b对外源乙烯、茉莉酸处理的响应时期早于对纹枯病菌、赤霉病菌的响应时期。【结论】分离出一个受病原诱导的小麦ERF新基因TaERF1b,其编码蛋白TaERF1b为植物ERF转录因子家族的一个新成员,可能通过茉莉酸、乙烯信号途径介导小麦对纹枯病菌、赤霉病菌的防御反应。     

紫花苜蓿愈伤组织诱导及愈伤组织对酸铝耐性的评价研究(英文)

苜蓿是最重要的豆科牧草之一,多适应于中性至微碱性土壤,为能在南方低pH条件下大面积推广种植,利用地方品种提高苜蓿的酸铝耐性成为育种的主要目标之一。该研究以6个品质优良、具有潜在高产优质的紫花苜蓿引进栽培种和云南野生种德钦苜蓿为材料,利用细胞培养技术进行耐酸铝性的评价研究。结果表明:7个品种中,耐酸铝性水平依次为GT13R牧歌701=牧歌702AcroraAC-3射手2号=德钦苜蓿。     

热研5号四倍体与3种柱花草的耐盐性比较分析

柱花草是豆科柱花草属多年生草本植物,是优良的热带牧草。本试验采用盆栽法对热研5号四倍体、热研2号、热研5号及西卡4种柱花草进行盐胁迫处理,通过观测其在盐胁迫下的一系列生理生化反应,并通过综合评价得出其耐盐性强弱,实验结果表明,当盐质量百分比为0.90%时,各生理生化指标开始受到影响,盐质量百分比达1.20%时各生长指标开始受到明显的影响,盐质量百分比达到1.80%时,大部分幼苗受到严重的影响,开始死亡。综合各项指标表明:在所选4种柱花草中,西卡的耐盐性最强,热研5号四倍体次之,热研2号耐盐性最差,4种柱花草在盐质量百分比小于0.90%时均能良好生长,当盐质量百分比达到1.80%时难以生存,热研5号四倍体和二倍体的耐盐性没有明显差异。     

普通小麦-百萨偃麦草染色体易位的选育与鉴定

 利用染色体C 分带、基因组原位杂交和花粉母细胞减数分裂分析的方法 ,从普通小麦中国春与中国春 百萨偃麦草双倍体回交BC1F5 代中选育出 5份纯合易位新种质 ,分别为 :含 1对易位染色体并添加 1对百萨偃麦草完整染色体的Tj0 1和Tj0 2 ;添加 1对易位染色体的Tj0 3 ;含 1对易位染色体并添加 1对百萨偃麦草某一染色体臂端着丝粒染色体的Tj0 4和含 1对易位染色体并添加 2对百萨偃麦草完整染色体的Tj0 5。这些易位染色体的易位断点均不在着丝粒处 ,能稳定传递 ,且所涉及的植株生长和结实均正常。推测在该回交后代中小麦与百萨偃麦草染色体之间发生了自发的部分同源重组 ,这将有利于百萨偃麦草优异基因向普通小麦的转移与利用     

Genetic Analysis of Cold Tolerance at Seedling Stage and Heat Tolerance atAnthesis in Rice (Oryza sativa L.)

A set of 240 introgression lines derived from the advanced backcross population of a cross between a japonica cultivar,Xiushui 09, and an indica breeding line, IR2061, was developed to dissect QTLs affecting cold tolerance (CT) at seedlingstage and heat tolerance (HT) at anthesis. Survival rate of seedlings (SRS) and spikelet fertility (SF), the index traits of CTand HT, showed significant differences between the two parents under stresses. A total of four QTLs (qSRS1, qSRS7,qSRS11a and qSRS11b) for CT were identified on chromosomes 1, 7, 11, and the Xiushui 09 alleles increased SRS at all lociexcept qSRS7. Four QTLs for SF were identified on chromosomes 4, 5, 6, and 11. These QTLs could be classified into twomajor types based on their behaviors under normal and stress conditions. The first was QTL expressed only under normalcondition; and the second QTL was apparently stress induced and only expressed under stress. Among them, two QTLs(qSF4 and qSF6) which reduced the trait difference between heat stress and normal conditions must have contributed toHT because of their obvious contribution to trait stability, and the IR2061 allele at the qSF6 and the Xiushui 09 allele at the qSF4improved HT, respectively. No similar QTL was found between CT at seedling stage and HT at anthesis. Therefore, it ispossible to breed a new variety with CT and HT by pyramiding the favorable CT- and HT-improved alleles at above locifrom Xiushui 09 and IR2061, respectively, through marker-assisted selection (MAS).     

花生油酸和亚油酸含量的遗传模式分析

【目的】利用F2遗传群体分析油酸和亚油酸含量的遗传模式,为高油酸种质的利用奠定基础。【方法】利用高油酸亲本wt08-0932和wt08-0934与普通（低）油酸含量品种配制杂交组合,建立不同杂交组合的遗传模型,并进行遗传参数估计,明确控制油酸性状的主基因个数、加性或显性效应值、遗传力等。【结果】获得控制油酸和亚油酸性状遗传的2对主基因加性-显性-上位性遗传模型,油酸和亚油酸性状的2对主基因遗传力分别为66%-89%和70%-85%,并存在多基因效应。控制油酸含量的2个主基因显性效应值均为负值,控制亚油酸含量的2个主基因的显性效应值均为正值。【结论】花生的油酸和亚油酸性状分别由2对主基因控制,同时存在基因互作及多基因效应。第一对主基因的加性和显性效应均大于第二对主基因。2对主基因同时变异形成高油酸性状;2对主基因之间的加性和显性效应的差异导致在1对主基因变异时形成中低油酸含量和中高油酸含量的性状表现。     

Detection of Allelic Variation in Chinese Wheat (Triticum aestivum L.) Germplasm with Drought Tolerance Using SSR Markers

Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yanda1817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157,Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.     

小麦与白黑麦、卵穗山羊草正反杂交的可交配性分析

小麦与白黑麦、卵穗山羊草正反杂交的可交配性分析＊叶兴国徐惠君李志武杜丽璞赵乐莲（中国农业科学院作物育种栽培研究所，北京１０００８１）ＣｒｏｓｓａｂｉｌｉｔｙＡｎａｌｙｓｉｓｏｆＲｅｃｉｐｒｏｃａｌＨｙｂｒｉｄｉｚａｔｉｏｎｓＢｅｔｗｅｅｎＣｏｍｍｏｎ...     

六倍体小黑麦花粉诱导普通小麦孤雌生殖的研究

为寻找可以提高普通小麦孤雌生殖诱导结实率的授粉者。对普通小麦品种间F1代去雄,然后延迟授以六倍体小黑麦花粉,以诱导其孤雌生殖。结果表明,3个六倍体小黑麦与对照黑麦相比,均能有效提高普通小麦孤雌生殖诱导结实率,差异均有显著意义。在诱导普通小麦孤雌生殖方面,六倍体小黑麦与黑麦相比更有应用价值。