Characterization of starch morphology,composition, physicochemi-cal properties and gene expressions in oat

Starch is the major carbohydrate in oat(Avena sativa L.) and starch formation requires the coordinated actions of several synthesis enzymes. In this study, the granule morphology, composition and physicochemical properties of oat starch, as well as the expressions of starch synthesis genes were investigated during oat endosperm development. Under the scanning electron microscopy(SEM), we observed that the unique compound granules were developed in oat endosperms at 10 days post anthesis(DPA) and then fragmented into irregular or polygonal simple granules from 12 DPA until seed maturity. The amylose content, branch chain length of degree of polymerization(DP=13–24), gelatinization temperature and percentage of retrogradation were gradually increased during the endosperm development; whereas the distribution of short chains(DP=6–12) were gradually decreased. The relative expressions of 4 classes of 13 starch synthesis genes characterized in this study indicated that three expression pattern groups were significantly different among gene classes as well as among varied isoforms, in which the first group of starch synthesis genes may play a key role on the initiation of starch synthesis in oat endosperms.     

新疆稻麦低分子量谷蛋白亚基基因序列分析

根据普通小麦低分子量谷蛋白亚基基因保守区序列,设计了一对引物(P1和P2),采用PCR法对新疆稻麦(Triticum petropavlovskyiUdacz.et Migusch)的基因组DNA进行扩增,获得1条约900 bp的片段,纯化后克隆到载体pMD18-T后,对筛选阳性克隆测序,获得1个基因LMWXJ-1(Genbank登录号:AY695380)。序列分析的结果表明LMWXJ-1具有典型的低分子量谷蛋白亚基基因的基本结构。推导的氨基酸序列比较结果表明,LMWXJ-1与Glu-A3和Glu-D3位点的低分子量谷蛋白基因具有较高的相似性(最高相似性分别为82%和80%),而与Glu-B3位点的差异较大(最高相似性仅有68%)。     

LMW-GS16基因表达载体的构建

采用PCR方法对来自大麦的LMW-GS16基因进行修饰,在基因5′及3′端分别加入构建表达载体所需的BamHⅠ和SacⅠ限制酶切位点,并将其连接在相应酶切的质粒pBI121上,构建成LMW-GS植物表达载体pBI121-16。重组质粒转化到E.coliDH5α和农杆菌LBA4404中,通过Kanamycin筛选阳性克隆,用PCR方法进行鉴定。对照组转化率为零,转化组阳性克隆特异地扩增出900 bp片段,与目标基因DNA大小一致,转化率为1.0×106/μg DNA。     

Quantitative Trait Loci Associated with Micronutrient Concentrations in Two Recombinant Inbred Wheat Lines

Micronutrient malnutrition affects over three billion people worldwide, especially women and children in developing countries. Increasing the bioavailable concentrations of essential elements in the edible portions of crops is an effective resolution to address this issue. To determine the genetic factors controlling micronutrient concentration in wheat, the quantitative trait locus （QTL） analysis for iron, zinc, copper, manganese, and selenium concentrations in two recombinant inbred line populations was performed. In all, 39 QTLs for ifve micronutrient concentrations were identiifed in this study. Of these, 22 alleles from synthetic wheat SHW-L1 and seven alleles from the progeny line of the synthetic wheat Chuanmai 42 showed an increase in micronutrient concentrations. Five QTLs on chromosomes 2A, 3D, 4D, and 5B found in both the populations showed signiifcant phenotypic variation for 2-3 micronutrient concentrations. Our results might help understand the genetic control of micronutrient concentration and allow the utilization of genetic resources of synthetic hexaploid wheat for improving micronutrient efifciency of cultivated wheat by using molecular marker-assisted selection.     

转Bt基因水稻氨基酸含量研究

利用酸水解法测定了转Bt基因水稻和常规水稻中的氨基酸含量,以期为转基因的生态学和安全性评价提供基础代谢方面的依据.结果表明:两种水稻中茎秆的氨酸含量均低于叶片.茎秆中,转Bt基因水稻的16种氨基酸含量均低于常规水稻,除组氨酸含量差异性不显著,蛋氨酸、酪氨酸、赖氨酸和脯氨酸含量差异性显著外,其余氨基酸含量差异性均极显著;叶片中,转Bt基因水稻中蛋氨酸含量高于常规水稻且差异性极显著,其余15种氨基酸的含量均低于常规水稻且差异性极显著.     

生长素对小麦幼胚组织培养的影响

以川农16、川麦42和良麦2号为供试材料,探讨了三种生长素对其幼胚组织培养的影响,并在此基础上筛选出相对较好的受体材料。结果表明,三种生长素在幼胚的诱导率、胚发芽率和胚发根率上存在极显著差异。2,4,5-T和NAA在诱导小麦幼胚培养基,其胚芽、胚根发生严重;而2,4-D在诱导率、胚发芽率和胚发根率这三方面相对优于2,4,5-T和NAA,适用于小麦幼胚的组织培养,且适宜浓度范围在2.0~2.5 mg/L。基因型对小麦幼胚组织培养的诱导率没有影响,对胚发芽率有一定影响,而对胚发根率有较大影响。在三种基因型中,以川农16在诱导率、胚发芽率和胚发根率这三方面表现相对突出,可作为转化受体材料。     

生态红线与耕地红线的基本概念比较

通过"耕地红线"与"生态红线"概念提出的相关背景进行分析,并对二者的概念及相关特征进行了相关界定与比较,期待在现有基础上,进一步明确"生态红线"的相关概念与特征,为下一步开展"生态红线"的相关研究做好理论铺垫。     

陆川猪3个产仔数相关基因的多态性及其效应分析

利用PCR-RFLP和PCR-SSCP技术对82头陆川猪个体的雌激素受体基因(ESR)、促卵泡激素β亚基基因(FSHB)和催乳素受体基因(PRLR)3个与产仔数相关基因的遗传多态性进行了检测.结果表明,ESR基因的BB基因型占绝对优势,不过由于AA型、AB型的样本量很少,因此难以计算出各基因型的产仔数差异;FSHβ基因只检测到了AA型;PRLR基因的AA型频率最高,AA型比BB型头胎和头4胎平均总产仔数分别多产1.42头和1.02头(P<0.05),AA型比BB型头4胎平均活产仔数多产1.43头(P<0.05).     

A major and stable QTL for wheat spikelet number per spike validated in different genetic backgrounds

The spikelet number per spike (SNS) contributes greatly to grain yield in wheat. Identifying various genes that control wheat SNS is vital for yield improvement. This study used a recombinant inbred line population genotyped by the Wheat55K single-nucleotide polymorphism array to identify two major and stably expressed quantitative trait loci (QTLs) for SNS. One of them (QSns.sau-2SY-2D.1) was reported previously, while the other (QSns.sau-2SY-7A) was newly detected and further analyzed in this study. QSns.sau-2SY-7A had a high LOD value ranging from 4.46 to 16.00 and explained 10.21–40.78% of the phenotypic variances. QSns.sau-2SY-7A was flanked by the markers AX-110518554 and AX-110094527 in a 4.75-cM interval on chromosome arm 7AL. The contributions and interactions of both major QTLs were further analyzed and discussed. The effect of QSns.sau-2SY-7A was successfully validated by developing a tightly linked kompetitive allele specific PCR marker in an F_2:3 population and a panel of 101 high-generation breeding wheat lines. Furthermore, several genes including the previously reported WHEAT ORTHOLOG OF APO1 (WAPO1), an ortholog of the rice gene ABERRANT PANICLE ORGANIZATION 1 (APO1) related to SNS, were predicted in the interval of QSns.sau-2SY-7A. In summary, these results revealed the genetic basis of the multi-spikelet genotype of wheat line 20828 and will facilitate subsequent fine mapping and breeding utilization of the major QTLs.     

Comparative Analysis of Hina Gene Sequences in Wild （Hordeum spontaneum） and Cultivated （H. vulgare） Barleys

The Hina gene is one of the two known Hin genes for hardness, and its RNA expression is correlated with grain hardness and dry matter digestibility variation. In this study, only one clone of Hina gene was obtained from one barley accession. A total of 121 Hina gene sequences were isolated from 121 wild barley {Hordeum spontaneum) accessions in Israel, Iran, and Turkey, and then their molecular characteristics were compared with 97 Hina gene sequences from 74 cultivated barley (H. vulgäre) lines in Europe and 23 landrace (H. vulgäre) with global distribution and other 26 Hina gene sequences from cultivated barleys (H. vulgäre) with unknown global distribution. C/s-acting regulatory element (CARE) searching revealed that there were different types of regulatory element for the Hina gene in wild and landrace/cultivated barleys. There were six consistent cw-acting binding sites in wild and landrace/cultivated barleys, whereas 8 to 16 inconsistent TATA-boxes were observed. In addition, three special elements (E2Fb, Spl, and boxS) were only observed in wild barley, while one (AT 1 -motif) was only found in landrace/cultivated barley. Forty-four deduced amino acid sequences of HINA from wild and landrace/cultivated barleys were obtained by deleting repetitive amino acid sequences, and they were clustered into two groups on the basis of Neighbor-Joining analysis. However, there was no obvious difference in the amino acid sequences of HINA between wild and landrace/cultivated barleys. Comparing to protein secondary structure of wheat PINA, it was indicated that HINA also existed a signal peptide. In addition, HINA was a hydrophilic protein on the basis of the protein properties and composition.