新疆小麦品种籽粒硬度及puroindoline基因等位变异的分子检测

为了解新疆小麦品种籽粒硬度概况和puroindoline基因等位变异类型及其分布,以121份新疆冬、春小麦品种(包括51份农家品种和70份育成品种)为材料,采用单粒谷物特性测试仪(SKCS)和分子标记技术,对其SKCS硬度及puroindoline基因型进行了测试和鉴定。结果表明,新疆小麦硬度变化范围较大,以硬质麦为主,占61.2%。冬性农家品种籽粒硬度高于春性农家品种,冬、春小麦育成品种籽粒硬度基本相同(60.6和60.8)。新疆小麦puroindoline基因的类型丰富,共检测到野生型(Pinb-D1 a)、Pina-D1 b、Pinb-D1 b、Pinb-D1 p、Pinb-D1 ab和Pinb-D1 ac6种类型。硬质麦以Pina-D1 b、Pinb-D1 p、Pinb-D1 b3种突变类型为主,其频率分别为33.8%、31.1%和28.4%。冬性农家品种含有3种类型,以Pina-D1 a/Pinb-D1 b类型居多,春性农家品种含有4种类型,以野生型(Pina-D1 a/Pinb-D1 a)为主,冬、春麦育成品种含有4种常见类型,其中冬麦以Pinb-D1 b类型为主,其频率为39.5%,春麦以Pina-D1 b(PINA缺失)类型为主,其频率为59.4%。另外,冬性农家品种中有4个品种属于Pina-D1 a/Pinb-D1 ab类型,春性农家品种中有1个品种属于Pina-D1 a/Pinb-D1 ac类型,均属硬质麦的稀有突变类型。不同puroindoline基因型的籽粒硬度大小也存在差异,其中Pinb-D1 ab突变型的硬度值最高,Pinb-D1 a最低,并且Pina-D1 b、Pinb-D1 b和Pinb-D1 p3种硬质类型的籽粒硬度没有显著性差异。     

CIMMYT普通冬小麦品种的籽粒硬度及Puroindoline基因等位变异

为给中国小麦种质资源引进、利用和品质改良提供信息,以国际玉米小麦改良中心（CIMMYT）土耳其育种站提供的192份普通冬小麦新品系为材料,采用单籽粒谷物特性测试仪、特异引物PCR扩增和改进的SDS-PAGE凝胶电泳方法对其SKCS硬度及Puroindoline基因型进行了鉴定和分析。结果表明,CIMMYT普通冬小麦以硬质类型为主,但SKCS硬度值普遍偏低,平均值仅为60．7。所调查的192份材料中,硬质麦119份,占62．0％;软质麦49份,占25．5％;混合麦24份,占12．5％。硬质小麦共有4种基因型,分别为PinA蛋白缺失类型（Pina-D1b／P1nb-D1a）90份、Pina-D1a／Pinb—D1b类型27份Pina—D1a／Pinb—D1d类型2份和Pina-D1b/Pinb-D1d类型1份,以PinA蛋白缺失类型为主,占总数的75．6％。Pina—D1b／Pinb-D1d为Pina和Pinb基因的双突变类型。CIMMYT普通冬小麦籽粒硬度及其Puroindoline基因变异类型和分布的信息能够为中国冬小麦品质改良提供理论依据。     

长江中下游麦区小麦品种籽粒硬度及puroindoline基因等位变异的分子检测

为了明确长江中下游麦区小麦籽粒硬度及puroindoline基因型的分布,以该麦区105份小麦育成品种为材料,利用单籽粒硬度仪(SKCS)测定其籽粒硬度,利用分子标记检测和基因序列分析鉴定puroindoline基因的等位变异。结果表明,在长江中下游麦区历年育成的小麦品种中软质麦比例较高,占52.4%,硬质麦和混合麦分别占38.1%和9.5%;硬质麦和混合麦中存在Pinb-D1b、Pina-D1b和Pinb-D1p三种变异类型,突变频率分别为29.5%、10.5%和3.8%。     

中国小麦历史品种puroindoline基因等位变异检测

小麦籽粒硬度是市场分级和定价的重要依据,由位于5D染色体短臂的一对主效基因和多个微效基因控制。为了解我国早期小麦品种的硬度分布规律,本试验以来自全国10个省市的126份历史品种和高代品系为材料,对其SKCS硬度和基因型进行了研究。结果表明,我国历史品种中软质麦所占比例较高,为42.9%,显著高于先前报道的我国当前主栽冬麦品种中的软质麦比例;硬质麦所占比例为44.4%,显著低于先前报道的我国主栽冬麦品种中的硬质麦比例。各种puroindoline变异类型中, PinaD1b类型和 PinbD1b类型所占比例较大,分别为42.9%和39.3%,其余硬质类型均为 PinbD1p类型,为17.8%。截至目前,所发现的 PinbD1p类型均在中国品种中,由于早期中国与其他国家种质资源交换较少,因此,中国可能是 PinbD1p类型的起源地。在对各种puroindoline类型的硬度比较后,发现除各种puroindoline变异类型与野生型硬度差异达显著水平外, PinaD1b类型硬度值也显著高于 PinbD1b和 PinbD1p类型,而后二者之间硬度没有显著差异。`     

陕西小麦籽粒硬度及其基因型分析

籽粒硬度与小麦市场分级定价、磨粉品质和食品加工品质密切相关。为给小麦品种选育和品种推广提供参考依据,用单籽粒谷物硬度测试仪测定了169份陕西小麦品种（系）的籽粒硬度,并利用分子标记检测和基因序列分析确定了硬质麦的基因组成。硬度测定结果表明,陕西参试小麦品种（系）存在硬质麦、混合麦和软质麦3种类型,分别为121、11和37份,依次占71.6%、6.5%和21.9%。陕西不同地区3种籽粒硬度类型所占比例明显不同。基因型分析结果表明,陕西硬质麦存在4种基因型,即PinaD1b、PinbD1b、PinbD1d和PinbD1p,分别有14、97、2和8份材料,占硬质麦比例依次为11.6%、80.2%、1.6%和6.6%。总体而言,陕西小麦以硬质麦为主,硬质麦主要由PinbD1b基因型组成。     

粗山羊草新型硬度等位基因的克隆及分析

小麦籽粒硬度是其最为重要的品质性状之一,现已发现控制小麦籽粒硬度的主效基因是Pina和Pinb。为了丰富籽粒硬度新型等位基因,根据已报道的小麦Pina和Pinb基因的保守序列,设计了2对特异性引物,对粗山羊草（Aegilops tauschii)进行Pina和Pinb基因的PCR扩增、克隆及序列分析。结果表明,本研究共得到2个新型Pina等位基因和3个新型Pinb等位基因,核酸序列长度均为447 bp,编码148个氨基酸残基,具有麦类作物PINA和PINB蛋白所特有的色氨酸结构域：WRWWKWWK和WPTKWWK。与已知的Pina和Pinb基因序列相比较,这些基因含有多个SNP变异位点,丰富了小麦籽粒硬度改良的遗传资源。[JP]     

普通小麦籽粒硬度的分子标记研究

籽粒硬度是决定小麦磨粉品质和食品品质的重要性状，蛋白复合体Friabilin的两种主要肽Puroindolinea（PinA）和Puroindolineb（PinB）是决定籽粒硬度的关键。用单籽粒谷物特性仪（SKCS）、PCR技术和改进的SDS-PAGE方法分析了85份小麦品种的籽粒硬度和基因突变形式，结果表明，与软质小麦相比，硬质小麦品种在基因或蛋白质表达水平上发生了变化，有31份野生型的软质小麦Pina-Dla／Pinb-Dla和6份Pina-D1b／Pinb-D1a突变型，42份Pina-D1a／Pinb-D1b和6份Pina—D1a／Pinb-D1p突变型。     

Wx基因变异对小麦籽粒胚乳质地的影响

为了明确Wx基因变异与小麦籽粒胚乳的关系,以玉米花粉诱导扬麦10号（角质胚乳品种,非糯小麦）与糯质供体Waxy C杂种F1产生的不同Wx基因变异类型的55个双单倍体系以及以扬麦9号（粉质胚乳品种）与不同糯质供体亲本杂交、回交育成的12个糯小麦品系为材料,研究了Wx基因变异对籽粒胚乳质地的影响,同时测定了12个不同来源的粉质胚乳糯小麦籽粒蛋白质含量。结果表明,角质胚乳品种扬麦10号与粉质胚乳糯质供体Waxy C杂交获得的3个糯质品系籽粒角质率分别为26％、38％和74％,非全糯质品系的角质率都在90％以上;粉质胚乳品种扬麦9号与不同糯质供体亲本杂交或回交产生的糯质品系籽粒胚乳都表现为粉质。说明3个Wx基因同时发生变异会导致籽粒角质率降低,而部分Wx基因变异类型之间及其与肌基因正常类型之间胚乳质地无显著差异。12个不同组合的糯小麦品系的平均蛋白质含量为13．79％,显著高于非糯质供体亲本扬麦9号、扬麦12、扬麦16和扬麦158的平均值（12．60％）,表明糯质小麦胚乳表现为粉质不是由蛋白质含量低引起的。     

青海小麦籽粒硬度等位变异研究

为了解小麦品种籽粒硬度的遗传多样性,利用单粒谷物硬度测定、PCR扩增和核苷酸测序技术,分析了66份青海小麦品种籽粒硬度主效基因的等位变异。结果表明,青海小麦以硬质类型为主,比例达到47.0%,混合麦比例为19.7%,软质麦比例为33.3%。硬度基因有5种组合类型:野生型、Pina-D1a/PinbD1b、Pina-D1a/Pinb-D1c、Pina-D1a/Pinb-D1x和Pina-D1b/Pinb-D1a。野生型小麦类型比例最高,占59.09%,SKCS硬度指数平均为44.12,变化范围为12.75~84.89。突变类型的品种籽粒均为硬质。因此,在青海硬质小麦可以通过突变类型的分子标记进行选育,软质小麦选育需在利用硬度基因分子标记筛选的基础上进一步考察籽粒硬度性状的表现型。     

小麦籽粒硬度及其Pinb-D1基因等位变异的STS标记检测

为了明确内蒙古春小麦和部分引进冬小麦的籽粒硬度及其等位变异类型,用SKCS 4100单籽粒谷物硬度仪和STS分子标记对17份冬小麦、87份春小麦品种扣38份春小麦高代品系的籽粒硬度及其Pinb-Dla,Pinb-D1b和Pinb-Dlc等位基因进行了分析.结果表明,在104份冬、春小麦品种中,籽粒硬度指数变幅为1±16～74±21,其中软质、混合和硬质麦频率分别为23.1%、49.0%和27.9%;Pina-D1a/Pinb-D1a、Pina-D1a/Pinb-D1b和Pina-D1a/Pinb-D1c基因型分憋为68份、27份和4份.在38份高代品系中,籽粒硬度指数变幅为O±18～49±17,软质和混合麦频率分别为68.4%和31.6%,Pina-D1a/Pinb-D1a和Pina-D1a/Pinb-D1b基因型分别为20份和18份.     

Reconciliation of D-genome puroindoline allele designations with current DNA sequence data

Kernel texture is an important trait in cereals, especially wheat (Triticum spp.). Throughout the Triticeae, the puroindoline genes act to soften kernel endosperm. Absence or mutation of either or both of the two puroindolines, ‘a’ and ‘b’, in Triticum aestivum results in harder grain texture. Apparently only one puroindoline haplotype was contributed by the Aegilops tauschii variety that contributed the D-genome during allopolyploidization. Yet, world collections of Ae. tauschii exhibit a range of puroindoline sequence polymorphisms. Consequently, these genes, through synthetic hexaploids (× Aegilotriticum) can enrich the wheat gene pool. Lastly, the puroindolines represent a useful tool for phylogenetic analyses. Here we review original sequence data published and/or available in public databases to reconcile the known gene sequence polymorphisms with a systematic approach to the designating of puroindoline gene and allele symbols in T. aestivum, Ae. tauschii, and × Aegilotriticum. This system follows the recommendations adopted by the International Wheat Genetics Symposium and described in the Catalogue of Gene Symbols for Wheat. Errors, discrepancies and ambiguities in the puroindolines are reviewed; a reconciliation of all existing data is outlined.     

Molecular mapping of the hybrid necrosis gene NetJingY176 in Aegilops tauschii using microsatellite markers

The rich genetic variation preserved in collections of Aegilops tauschii can be readily exploited to improve common wheat using synthetic hexaploid wheat lines. However,hybrid necrosis, which is characterized by progressive death of leaves or plants, has been observed in certain interspecific crosses between tetraploid wheat and Ae. tauschii. The aim of this study was to construct a fine genetic map of a gene(temporarily named Net Jing Y176)conferring hybrid necrosis in Ae. tauschii accession Jing Y176. A triploid F1 population derived from distant hybridization between Ae. tauschii and tetraploid wheat was used to map the gene with microsatellite markers. The newly developed markers Xsdau K539 and Xsdau K561 co-segregated with Net Jing Y176 on chromosome arm 2DS. The tightly linked markers developed in this study were used to genotype 91 Ae. tauschii accessions. The marker genotype analysis suggested that 49.45% of the Ae. tauschii accessions carry Net Jing Y176. Interestingly, hybrid necrosis genotypes tended to appear more commonly in Ae. tauschii ssp. tauschii than in Ae. tauschii ssp. strangulata.     

Puroindoline grain hardness alleles in CIMMYT bread wheat germplasm

Grain hardness is an important quality parameter of bread wheat (Triticum aestivum L.) with importance for wheat classification and end use properties, and is controlled by the genes puroindoline a (Pina) and puroindoline b (Pinb). The presence of known hardness alleles was studied in a representative sample of 373 bread wheat lines from the breeding program at CIMMYT. The PINA-null mutation (Pina-D1b) was the most frequent hardness allele and present in 283 of the 328 lines with hard endosperm. All other hard wheat had the glycine to serine mutation in PINB (Pinb-D1b). A study of historically important CIMMYT bread wheat lines showed that Pina-D1b has been the dominating hardness allele since the inception of the wheat breeding program in Mexico. New puroindoline alleles have recently been introduced through the extensive use of synthetic hexaploid wheat, and the textural effects of various Aegilops tauschii-derived Pina and Pinb alleles were studied in 92 breeding lines derived from various crosses with synthetic wheat. Progeny lines with Pina-D1j/Pinb-D1i were on average 10 SKCS hardness units softer than those carrying the allelic combination Pina-D1c/Pinb-D1h. Further investigation is needed to validate the potential of such minor allelic differences for the improvement of soft wheat quality.     

The effects of puroindoline b on the ultrastructure of endosperm cells and physicochemical properties of transgenic rice plant

Endosperm texture is an important factor governing the end-product quality of cereals. The texture of wheat (Triticum aestivum L.) endosperm is controlled by puroindoline a and b genes which are both absent in rice (Oryza sativa L.). It has been reported that the endosperm texture of rice can be modified by puroindoline genes. The mechanism, however, by which puroindolines affect the ultrastructure of rice endosperm cells remains to be investigated. In this study, we observed the ultrastructure of endosperm cells and the morphology of isolated starch granules of the transgenic rice expressing the puroindoline b gene. SEM and TEM observations indicated that compound starch granules were embedded within the matrix material in non-transgenic rice, Nipponbare, whereas they were surrounded by spaces in the transgenic rice. The morphology and size of each starch granule were not different between non-transgenic and the transgenic rice. However, the transgenic rice flour showed smaller particle size, higher starch damage, and lower viscosity during gelatinization than that of non-transgenic rice. These results confirm that puroindoline b reduces the grain hardness in rice. Moreover, the results also suggest that puroindoline b functions at the surface of compound starch granules, and not on polygonal starch granules in rice endosperm.     

三种山羊草细胞质对普通小麦F1代穗部性状的效应

为了研究3种山羊草细胞质对普通小麦穗部性状的遗传效应,以普通小麦品系303,706及利用其曰交转育的粘果山羊草(Ae.kotschyif）、瓦维洛夫山羊草(Ae．vavilavii)和牡山羊草(Ae．juvenalis)细胞质雄性不育系为母本、13个普通小麦品系为父本,进行不完全双列杂交,研究了瓦维洛夫山羊草、粘果山羊草、牡山羊草三种细胞质对普通小麦F1代穗部性状的细胞质效应。试验结果表明,与普通小麦细胞质相比,三种山羊草细胞质对普通小麦有效小穗和无效小穗数不产生正向和负向的细胞质效应。