小麦微核心种质γ射线辐射敏感性分析

以259个小麦微核心种质为材料进行剂量为0、100、150、250 Gy的60Coγ射线辐照处理,探讨小麦微核心种质的γ射线辐射敏感性分布,以及DNA损伤修复基因TaKu70和TaKu80对辐照的应答模式。结果表明,小麦微核心种质的苗高损伤率与γ射线辐照剂量间存在着3种函数关系:对数、线性、幂函数。以苗高损伤率为50%时的辐照剂量HD50作为主要的辐射敏感性分型指标,分别统计不同函数关系的微核心种质落入不同剂量区间的基因型个数,并依此将259份微核心种质分为敏感型(10)、较敏感型(96)、较钝感型(101)、钝感型(52)。对数函数关系中以敏感型和较敏感型为主,随着γ射线辐照剂量的增加TaKu70和TaKu80基因的相对表达量与对照相比总体升高,但变化不明显;线性函数关系中以较敏感型和较钝感型为主,TaKu70和TaKu80基因的相对表达量与对照相比总体升高,随剂量的增加而逐渐递增;幂函数关系中以较钝感型和钝感型为主,TaKu70和TaKu80基因的相对表达量与对照相比总体升高,但随剂量的增加呈现先增加后降低的趋势,一般相对表达量的峰值出现在150 Gy。     

中国普通小麦初选核心种质的产生

对中国普通小麦种质资源构建了初选核心种质。地方品种和选育品种分别构建。按栽培区(地理生态区)分组。地方品种按亚区分为28组,选育品种按大区分为10组。各组内在21个表型性状聚类的基础上,按平方根法取样,并依遗传多样性指数与遗传丰富度加以调整。提出在生产上或育种中起过重要作用的品种为必选材料。初步选定的材料经种植核对,淘汰错杂后,产生初选核心种质。地方品种全部供试材料11694份,初选核心种质3283份,取样比例为28．18％。选育品种全部11441份,初选核心种质1684份,取样比例为14．9％。计划经分子标记分析,最后核心种质的比例占全部种质的10％左右。根据全部材料21个性状遗传多样性指数测验,初选核心种质,除芒和壳两性状外,与全部种质的遗传差异均未达到显水平。讨论了初选核心种质的构建方法。指出陕南部西山地和汾渭谷地是中国小麦地方品种遗传变异多样性的富集地。育成品种多样性程度以西南冬麦区和黄淮冬麦区为最高。     

中国大麦矮秆种质资源的基因分析：Ⅰ.矮秆遗传和等位测验

了２４份中国大麦矮秆种质资源的株高遗传,在它们的矮秆基因之间且与已矮秆基因ｕｚ、ｓｄｗ、ｂｒ和ｅｎｓｏ进行遗传等位性测验。结果表明,这些矮秆种在多隐性单基因遗传,少数受隐性基因控制,只有１份携带１对隐性和１对不完全显性筹秆基因。     

美国花生微核心种质资源纯化系的引进与表型评价

花生种质资源是花生新品种选育和重要农艺性状遗传研究的基础材料。引进国外优异花生种质资源,并对其进行鉴定和评价对发掘优良花生种质、丰富我国花生资源遗传多样性以及合理利用种质资源进行遗传改良具有重要意义。本研究于2014-2015年连续2年在河北保定对104份引进的美国花生微核心种质资源纯化系进行了农艺性状考察和抗病性鉴定。鉴定结果表明,美国微核心种质纯化系多为匍匐型,主茎高变异范围为24.50~89.50 cm,侧枝长为39.37~99.23 cm,单株果数和单株果重分别为8.75~46.33个和8.49~29.54 g,百果重为80.76~216.72 g,单株粒数为18.25~58.00个,单株粒重为9.89~33.36 g,百仁重为25.52~74.18 g,出仁率为52.58%~76.08%。抗病性鉴定表明,部分美国微核心种质资源纯化系高抗褐斑病和网斑病,性状优良。该研究结果为花生新品种选育与遗传研究提供了优异材料和参考信息。     

我国水稻微核心种质资源对白叶枯病抗性的鉴定和评价

由Xanthomonas oryzae pv.oryzae(Xoo)引起的白叶枯病是水稻生产中普遍发生、危害严重的一种细菌病害。本研究采用我国和菲律宾的6个Xoo代表菌株,人工接种评价了来源于我国26个省份的174份水稻微核心种质资源对白叶枯病的抗性。结果表明,来源于不同稻作区的种质资源以及籼粳亚种对白叶枯病的抗性存在明显分化,6个粳稻品种和7个籼稻品种对2个或2个以上的菌株具有抗性,其中7-304、山酒谷、麻谷子、包二幅以及古154抗谱较广。本文的研究结果将为水稻抗白叶枯病育种提供有用的信息。     

乙型肝炎病毒（HBV）核心基因的变异及分析

对１８份不同类型的乙型肝炎病毒感染者血清及４份肝癌组织,用套式ＰＣＲ扩增ＰｒｅＣ／Ｃ基因,结果１５份标本可供进行核苷酸序列分析。１２例血清标本在Ｃ区均出现点突变并导致氨基酸改变。１份肝癌患者的血清及癌组织与另１份癌组织中获得的Ｃ基因克隆有２１３－３２４个核苷酸缺失。     

珙桐的等位酶位点变异分析

18 69年法国人 Armand David在四川宝兴县穆坪首次采到珙桐的标本 ,并由 Baillion H.E.定名为Davidia involucrata。该种发表后 ,立即引起世界植物学家们的关注 〔1〕。由于珙桐生境的特殊性 ,以及其在自然条件下种子萌发率很低的生殖生物学特性和它在植物系统学上的特殊地位〔2〕,珙桐被确定为我国的一级保护植物。因珙桐花序下的大苞片形状酷似飞鸽 ,故在国外有“中国鸽子树”的美称 〔1〕,是世界上著名的园林观赏树种。为了科学地制定出对珙桐的保育策略 ,我国的植物学工作者曾对珙桐的繁殖生物学、栽培技术和群落生态学特征进行了调…     

小麦新种质241千粒重的基因定位

以小麦新种质材料241为测定系,中国春单体系及双端体系作为测验系,对控制千粒重的基因进行了定位研究,结果表明,小麦新种质材料241的3A,2B,7B和6D染色体上具有控制千粒重的基因,其中3A,7B和6D染色体上的基因表现为强效, 2B染色体上的基因表现为弱效,通过双端体分析进一步将控制千粒重的基因定位到3AL,7BL和6DL上,其中6DL上可能具有控制241千粒重的新基因。     

黄淮麦区地方小麦品种籽粒颜色相关基因Tamyb10-1等位变异检测?

Tamyb10-1基因属于MYB家族的一种转录因子,决定着小麦种皮的颜色,同时对穗发芽抗性也具有一定影响。本研究以来自我国黄淮麦区的地方小麦品种为材料,利用功能标记对参试小麦品种Tamyb10-1基因位点在3A、3B和3D染色体上的等位变异类型进行了检测。结果表明,参试材料中上述每一位点均有2种等位变异类型,由此形成了7种基因型组合,分别为Tamyb10-A1a/Tamyb10-B1a/Tamyb10-D1a、Tamyb10-A1a/Tamyb10-B1a/Tamyb10-D1b、Tamyb10-A1a/Tamyb10-B1b/Tamyb10-D1a、Tamyb10-A1b/Tamyb10-B1a/Tamyb10-D1a、Tamyb10-A1b/Tamyb10-B1b/Tamyb10-D1a、Tamyb10-A1b/Tamyb10-B1a/Tamyb10-D1b和Tamyb10-A1b/Tamyb10-B1b/Tamyb10-D1b,其分布频率分别为38.0%、15.0%、1.0%、8.0%、1.0%、33.0%和4.0%。进一步研究结果表明,种皮颜色为白色时,Tamyb10-1基因在3个位点均为野生型,而当任何一个位点发生突变时均表现为红色。由于该基因也影响穗发芽的抗性,且子粒颜色与其抗氧化能力密切相关,因此本研究对以子粒颜色性状为育种目标的优异种质资源筛选具有一定参考价值。     

中国饭豆种质资源遗传多样性及核心种质构建

饭豆耐瘠、耐旱、抗病虫性强,是绿豆、小豆等近缘栽培作物育种的优异基因来源。但饭豆种质资源研究落后,利用效率低。本文首次对我国保存收集的饭豆种质资源进行农艺性状的变异分析。结果表明,我国饭豆种质资源质量性状变异类型丰富,但不同变异类型的分布频率差异较大,大部分稀有变异类型呈区域性分布。数量性状也具有较大的分布范围,各性状的变异系数在14%~98%之间,其中单株荚数>主茎分枝数>株高>百粒重>单荚粒数>生育期>荚长。不同地理来源饭豆资源群体的数量性状变异水平也存在差异。聚类分析不能完全把同一省份来源的种质聚在一起,但是个别省份的有些种质成簇出现在聚类图上,进一步分析发现这些成簇种质的数量性状和经纬度来源比较一致,可能为重复保存。最后以聚类分析为基础,按照比例法进行类内随机取样,并经评价和补充调整等构建了我国饭豆核心种质157份,为有重点有选择地深入开展饭豆种质资源研究及利用等提供了很好的样本。     

小麦黄色素合成途径中Psy基因的克隆及分子特性

对普通小麦(Ttiticum aestivum)黄色素(YP)合成途径中的首要限速酶——八氢番茄红素合成酶(Psy)基因进行克隆和测序,并和玉米Psy基因进行序列比对。结果表明,在高和低YP含量小麦品种中均扩增出一条长1192bp的Psy基因片段,该片段包含一条可编码78个氨基酸的小麦Psy基因的外显子,与玉米Psy基因第4外显子的核苷酸序列同源率为80.74,同源区域内有47个SNPs,但仅11个SNPs导致氨基酸编码序列的改变,二者氨基酸序列的同源率达85.89,推测Psy基因在不同物种中的表达具有较高的保守性。BLAST聚类分析表明,禾谷类植物Psy基因的分类与物种的亲缘关系存在明显的相关性,小麦Psy基因在系统进化中比禾谷类其他植物更为高级。     

小麦黄色素合成途径中Psy 基因的克隆及分子特性小麦黄色素合成途径中Psy 基因的克隆及分子特性

对普通小麦( Ttiticum aestivum) 黄色素(YP) 合成途径中的首要限速酶———八氢番茄红素合成酶(Psy) 基因进行克隆和测序, 并和玉米Psy 基因进行序列比对。结果表明, 在高和低YP 含量小麦品种中均扩增出一条长1 192 bp 的Psy 基因片段, 该片段包含一条可编码78 个氨基酸的小麦Psy 基因的外显子, 与玉米Psy 基因第4 外显子的核苷酸序列同源率为80 . 74% , 同源区域内有47 个SNPs , 但仅11 个SNPs 导致氨基酸编码序列的改变, 二者氨基酸序列的同源率达85 . 89% , 推测Psy 基因在不同物种中的表达具有较高的保守性。BLAST 聚类分析表明, 禾谷类植物Psy 基因的分类与物种的亲缘关系存在明显的相关性,小麦Psy 基因在系统进化中比禾谷类其他植物更为高级。     

Allelic variants of phytoene synthase 1 (Psy1) genes in Chinese and CIMMYT wheat cultivars and development of functional markers for flour colour

Phytoene synthase genes influence yellow pigment (YP) content in wheat grain, and are associated with the quality of end-use products. In the present study, a suite of 217 Chinese winter wheat cultivars and 342 CIMMYT spring wheat cultivars were used to search for phytoene synthase 1 gene variations and to detect and compare their genetic effects in different genetic backgrounds. An initial focus on the Chinese winter wheat cultivars revealed four allelic variants of this gene on chromosome 7B (Psy-B1), designated as Psy-B1a, Psy-B1b, Psy-B1c and Psy-B1d. The frequencies of these four alleles were 39.6, 43.8, 15.7 and 0.9%, respectively. A co-dominant marker YP7B-1 based on a 5-bp InDel of poly C in the fifth intron of Psy-B1 amplified a 151-bp PCR fragment in accessions with the medium YP content allele Psy-B1a, and a 156-bp fragment in lower YP content accessions with Psy-B1b. Two dominant markers YP7B-2 (428 bp) and YP7B-3 (884 bp) were designed for accessions with Psy-B1c and Psy-B1d, respectively. Allele Psy-B1c was associated with high YP content, but the phenotypic effect of Psy-B1d was not determined due to the limited number of accessions. In CIMMYT spring wheat cultivars, Psy-B1a, Psy-B1b, Psy-B1d and a further allelic variant, Psy-B1e, were detected with frequencies of 50.6, 29.2, 19.6 and 0.6%, respectively. Psy-B1c was not found in the CIMMYT germplasm. However, no significant differences were detected for mean YP content among CIMMYT wheat lines with different Psy-B1 genotypes. A new allelic variant of Psy-A1, designated Psy-A1c, was identified in three CIMMYT wheat lines, and this allele was associated with higher YP content. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Novel Natural Allelic Variations at the Rht-1 Loci in Wheat

Plant height is an important agronomic trait. Dramatic increase in wheat yield during the“green revolution”is mainly due to the widespread utilization of the Reduced height (Rht)-1 gene. We analyzed th...     

Novel Natural Allelic Variations at the Rht-1 Loci n Wheat

Plant height is an important agronomic trait. Dramatic increase in wheat yield during the ＂green revolution＂ is mainly due to the widespread utilization of the Reduced height （Rht）-1gene. We analyzed the natural allelic variations of three homoeologous loci Rht-A1, Rht-B1, and Rht-D1 in Chinese wheat （Triticum aestivum L.） micro-core collections and the Rht-B1/D1 genotypes in over 1,500 bred cultivars and germplasms using a modified EcoTILLING. We identified six new Rht-A1 allelic variations （Rht-Alb-g）, eight new Rht-B1 allelic variations （Rht-Blh-o）, and six new Rht-D1 allelic variations （Rht-Dle-j）. These allelic variations contain single nucleotide polymorphisms （SNPs） or small insertions and deletions in the coding or uncoding regions, involving two frame-shift mutations and 15 missenses. Of which, Rht-Dle and Rht-Dlh resulted in the loss of interactions of GID1-DELLA-GID2, Rht-Blicould increase plant height. We found that the Rht-Blh contains the same SNPs and 197 bp fragment insertion as reported in Rht-Blc. Further detection of Rht-Blh in Tibet wheat germplasms and wheat relatives indicated that Rht-Blc may originate from Rht-Blh. These results suggest rich genetic diversity at the Rht-1 loci and provide new resources for wheat breeding.     

Allelic variation in srtAs of Streptococcus suis strains

Streptococcus suis NCTC10234 possesses five srtA homologs: srtA encodes sortase, which anchors surface proteins with an LPXTG motif to the cell wall, while the functions of the other four homologs (the srtBCD cluster and srtE) remain unknown. The genetic organization of the srtA region was found to be conserved in the 59 S. suis strains examined in this study. Although the srtAs in three of these strains showed strong sequence divergence, their functions were verified to be overlapping by genetic complementation, indicating the functional conservation of srtAs during the evolution of these strains. These results indicate the importance of an srtA-mediated cell wall sorting system for displaying proteins on the surface of S. suis.     

Allelic variation of the serotonin transporter gene polymorphic region in apes

To assess the change of serotonin transporter (5-HTT) gene-linked polymorphic region that has occurred during the process of hominization, we examined the allelic variation of 5-HTT gene-linked polymorphic region (5-HTTLPR) in anthropoid apes such as chimpanzees, gorillas, orang-utans, and gibbons, and determined the DNA sequences of the alleles in each species. All chimpanzees examined shared only the 17.5 repeat allele, while polymorphism was observed in the other apes and the 16 and 20 repeat alleles were most frequent in gorillas and orang-utans, respectively. 5-HTTLPR was highly polymorphic in gibbons and the 17 and 23 repeat alleles were most common among 5 alleles. Alleles with extra-long repeated (22 and 23) sequences were found in orang-utans and gibbons, and the alleles of these Asian apes were similar to the rhesus monkey allele.     

小麦背景中黑麦1R染色体的遗传变异

运用细胞遗传学方法鉴定了来源于中国春×Ｍ２７（１Ｒ／１Ｄ代换系）的花粉植株和Ｆ２单株染色体组成。发现７个花粉植株中出现７种染色体组成变异类型,每株呈现一类变异;而２７个Ｆ２单株中,存在１１种染色体组成变异类型,变异频率仅为３７．０％,低于花粉植株。花粉植株群体中,观察到一个能稳定向后代传递的小麦／１Ｒ小片段易位,但Ｆ２群体中未检测到小麦／黑麦易位。表明常规染色体工程结合花药培养是有计划、有目的实现异源染色体小片段向小麦转移的简便、高效、快速途径。     

Nucleotide Sequence of A High-Molecular-Weight Glutenin Gene in Wheat

Subclones of a wheat (Triticum aestivum L. cv. asarce) genomic recombinant containing high-molecular-weight (HMW) glutenin gene were constructed by using pUCll8/pUCll9 vectors, their successive shorter deletions were also prepared: The nucleotide sequence of about 560 bp upstream of initiation codon and total coding region was analysed by Sanger's dideoxynucleotide chain termination method. It has 3067 bp which includes 830 codons and reveals high homology with a previously reported HMW glutenin gene. This gene contains no intron but a TAA termination codon within the coding region. Whether this is a silent gene or not merits further investigation.