小麦高分子量谷蛋白亚基基因的PCR及AS-PCR标记

选用高分子量麦谷蛋白亚基(HMW-GS)在Glu-D1位点已知的 26个普通小麦品种,包括 15个 (TriticumaestivumL. )川育系列品种及其 11个亲本,根据其亚基Dx5和Dy10基因的特异序列设计引物.通过对Dx5基因的PCR扩增及对Dy10基因的AS-PCR扩增,结果表明,所设计的引物对Dx5和Dy10都能扩增出特异条带,而携有Dx5基因的材料同时也携有Dy10基因.说明用所设计的引物可快速有效的鉴定出普通小麦中是否带有优质的 5 10亚基.图 4参 15     

青稞B-hordein基因表达载体构建及对小麦的遗传转化

利用从具有特殊B-hordein亚基组成的青藏高原青稞材料中克隆的B-hordein编码基因(SL60)和小麦高分子量谷蛋白亚基胚乳特异表达启动子PGlu1Dx构建了真核表达载体pCB2007-SL60.通过农杆菌介导对普通小麦进行遗传转化,共获得227株再生植株,经PCR鉴定和转化片段测序验证,最终获得5株阳性植株.研究为进一步分析B-hordein基因在小麦背景中的遗传和表达,以及对小麦加工特性的影响奠定了基础.图5表2参21     

转基因小麦麦谷蛋白亚基突变体类型

采用十二烷基磺酸钠–聚丙烯酰胺凝胶电泳技术,分析了含外源1Dx5和1Ax1的T7代转基因小麦HMW-GS的突变类型及等位变异.结果显示,随机挑选的1000份B72-8-11bT6代籽粒在T7代中共21类突变类型,其外源1Dx5基因表达频率为49.4%,GluA1、GluB1和GluD1共3、13和9个等位变异类型,分别以N、17+18和N为主,占94.7%、61.5%和49.7%;B102-1-2共11类,外源1Ax1基因表达频率占95%,GluA1、GluB1和GluD1共2、7和3个等位变异类型,分别以1、17+18和N为主,占95%、98.7%和98.3%。研究结果进一步说明了转基因株系的纯合性,完全符合孟德尔遗传分离规律,对小麦优质新品种的培育具有理论意义和应用价值.     

川育小麦高分子量谷蛋白亚基组成分析

对15个川育系列品种及其16个亲本进行了沉降值测定，并采用SDS—PAGE方法分析了供试品种的高分子量谷蛋白亚基的组成及分布，分析了不同亚基与SDS沉降值的关系．结果表明，近期育成的优质小麦品种中含有优质HMW亚基，如5 10，而一些早期育成的品种由于缺乏优质亚基，其品质也稍差一些，因此在今后的品质育种工作中应加强对优质亚基的引进、研究和利用．加强HMW—GS在品质育种中的应用与实践．图2表8参12     

偏凸山羊草6M~v染色体在不同四川小麦品种中的传递

利用高抗条锈病的小麦-偏凸山羊草6Mv/6B代换系(Moisson 6Mv/6B)与高感条锈病的四川小麦绵阳26、绵阳93-124和SW3243进行杂交,并用这些品种分别与杂种F1进行正反回交,通过对其F1、F2和BC1的结实率观察、细胞学分析以及条锈病抗性反应鉴定,研究了偏凸山羊草6Mv染色体在不同四川小麦背景中的传递频率,分析了代换染色体6Mv代偿6B的能力.结果显示,当含6Mv染色体的F1植株作母本时,平均回交结实率为83.10%,最高可达95.51%;而含6Mv染色体的F1植株作父本时,平均回交结实率则为48.61%,最低仅为28.47%,暗示6Mv染色体可能对花粉参与受精的能力有一定不利影响,且结实率与小麦基因型相关.在与绵阳26、绵阳93-124和SW3243的所有杂交组合中,6Mv染色体通过雌、雄配子的传递率没有显著差异,但其传递率与小麦品种显著相关.另外,在单体代换植株中6Mv染色体通过自交的传递率也受小麦品种基因型的影响.研究结果为小麦-偏凸山羊草6Mv/6B代换系在小麦育种上的利用提供了理论依据.     

不同水氮处理对糯小麦品质性状的影响

在盆栽试验条件下,以糯麦12为材料,研究3个水分水平(渍水、对照、干旱)和两个氮肥水平(不追施氮肥、追施氮肥)共6个处理对糯小麦糖类、淀粉、蛋白质含量等品质的性状影响.结果表明:糯小麦的主要品质性状存在显著的水氮效应,且在淀粉、戊聚糖含量、SDS沉降值、PPO活性性状品质上,水氮间存在着显著的互作效应.水分对照处理(水分含量适宜)下,追施氮肥可显著降低糯麦12可溶性糖含量,降低10.7%;干旱处理下糯小麦总糖含量最低,果聚糖含量提高;渍水处理下追施氮肥,糯麦12籽粒中戊聚糖和果聚糖含量分别提高66.8%和69.2%;水氮互作对淀粉含量的影响达显著水平,在水分对照处理+追施氮肥处理下,糯麦12的淀粉含量提高7.84%;水分对照处理下糯麦12的蛋白质含量最高,追施氮肥可进一步提高糯小麦籽粒蛋白质含量;追施氮肥可提高适宜水分和渍水处理条件下糯麦12的SDS-沉降值,并降低其PPO活性.干旱处理下糯麦12的峰值粘度、最终粘度、稀懈值最高,表明干旱条件下有利于提高糯小麦淀粉糊化特性各项指标.本研究结果表明,水氮合理运筹是改善糯小麦品质的重要栽培措施.     

成熟小麦种子中残留的α-淀粉酶对小麦馒头品质的影响

α-淀粉酶通过降解淀粉产生发酵糖,并改变淀粉的物化特性,进而影响小麦制品的品质,其影响与α-淀粉酶来源、含量及小麦制品种类有关.成熟小麦籽粒中残留的α-淀粉酶活性存在极大差异,为了解迟熟α-淀粉酶对馒头品质的影响,以重组自交系群体中α-淀粉酶活性极端的小麦品系为材料,比较高低酶活材料制作的馒头品质之间的差异;并依据小麦材料α-淀粉酶活性的分布范围,设定不同的外源α-淀粉酶浓度,研究外源α-淀粉酶对小麦馒头质构、感官品质及微观结构的影响.结果显示,过高的内源α-淀粉酶含量(降落值小于300 s)会导致馒头的高径比及质构参数下降,这种变化趋势与添加过多外源α-淀粉酶的效果类似;α-淀粉酶含量过高,造成淀粉糊化过度,产气过多,馒头内部结构被破坏,持气能力降低,馒头塌陷;降落值不低于300 s的材料制作的馒头品质较好.本研究表明成熟种子中残留的α-淀粉酶对馒头品质有显著影响,优质馒头品种选育时应关注小麦α-淀粉酶活性的差异.(图4表11参35)     

高产小麦品种川麦42产量性状QTL分析

解析骨干亲本产量性状分子模块对小麦品种分子设计与分子育种具有重要作用.以突破性高产小麦品种川麦42和川农16及其构建的127个重组自交系(RIL)群体(F10)为实验材料,分别于2014年和2015年在四川双流、什邡3个环境下种植,并测量千粒重、穗粒数等产量性状.利用Illumina公司的小麦90K SNP芯片对亲本和群体进行全基因组81 587个单核苷酸多态性分型.使用QTL Ici Mapping软件绘制遗传连锁图,并定位到一些控制产量性状的数量性状位点(QTL).结果显示:遗传图谱含8 580个SNP标记,全长3 147.1 c M,平均密度0.37 c M/标记.共定位到21个效应来自川麦42的产量性状QTL(解释表型变异10%),分别位于1B、1D、2B、2D、3B、3D、4A、5A、5B、6B和7B,控制着株高、穗长、穗重、千粒重等性状,解释表型变异10.01%-23.07%.其中,1D、2B、5A、5B存在控制株高、籽粒面积、千粒重、穗长、穗重,并且在多个环境下均出现的QTL.此外,2B、5A、5B、7B上存在同时控制多个性状的QTL.这些研究结果可为深入了解骨干亲本川麦42产量性状遗传特性提供重要信息.     

利用SNP基因芯片技术进行小麦遗传图谱构建及重要农艺性状QTL分析

小麦遗传图谱是进行小麦染色体分析和表型研究的遗传基础.构建高密度遗传图谱,针对小麦重要农艺性状进行初级定位,确定相关性状主效数量性状位点(Quantitative Trait Loci,QTL),有助于开发辅助选择的实用性标记,并为利用次级群体进行精细定位和基因挖掘奠定基础.本研究以H461×CN16的重组自交系(Recombinant Inbred Line,RIL)为作图群体,利用90k小麦SNP基因芯片技术,对包含188个家系的RIL群体(F7)进行多态性分析,构建高密度遗传图谱,并利用Map QTL5.0的多QTL模型(MQM),对旗叶长、穗粒数等8个重要农艺性状进行QTL定位分析.构建了包括43个连锁群的分子遗传图谱,成功连锁到除2D、5D、6D外的18条染色体.该图谱共含有6 573个多态性SNP标记,覆盖的遗传距离长2 647.02 c M,标记间平均距离仅为0.4 c M.A、B、D三个染色体组分别含有标记2 696、3 094和684个;覆盖染色长度分别为1 130.92 c M、1 164.82 c M和330.44 c M;分别建立19、18和5个连锁群.对8种重要田间农艺性状进行QTL分析,共检测到66个重要农艺性状QTL,其中包括26个主效QTL,包含未见报道的新位点7个.全部QTL分布于2A、4A、6A、2B、4B、5B、2D、4D、7D 9条染色体上,单个QTL可解释表型变异率7.4%-19.5%,其中62个QTL加性效应来自母本H461,其余来自父本CN16.以上结果为小麦重要农艺性状QTL精细定位打下了基础,也为分子标记辅助育种提供了参考.     

沼液对莴笋和生菜硝酸盐含量及营养品质的影响

采用盆栽试验 ,研究了不同沼液用量对莴笋、生菜硝酸盐含量和营养品质的影响。结果表明 ,施用沼液提高了莴笋、生菜株高和产量 ,降低了莴笋茎和生菜硝酸盐含量 ,有利于增加莴笋茎、叶及生菜含水量和氨基酸含量 ,生菜维生素C含量略高于对照。在施用氮磷钾化肥 (N 12 0mg·kg-1、P2 O580mg·kg-1、K2 O 10 0mg·kg-1)基础上 ,每钵增施沼液 5 0 0ml,可改善蔬菜营养品质 ,使莴笋叶和生菜硝酸盐含量分别降低 5 3.5 %和 4 5 .5 % ,同时还可使 2种蔬菜分别增产 5 1.0 %和 5 6 .7% ,为本试验条件下莴笋、生菜最佳施肥组合。     

Genetic differentiation of Texas Gulf Coast populations of the blue crab Callinectes sapidus

Allelic frequencies at three polymorphic, enzyme-encoding gene loci (GOT-2, EST-1, EST-2) were determined for Callinectes sapidus (Rathbun) megalopae and adults sampled along the Texas coast of the Gulf of Mexico. Significant temporal and spatial variation was observed at all three loci. Primary findings included: (1) megalopal allelic frequencies often differed significantly from those observed among neighboring adult populations; (2) larval allelic frequencies appeared to vary seasonally, with populations showing sharp differences in the summer months but tending to be more homogeneous in winter; (3) allelic frequencies among adult populations were significantly heterogeneous, but only one locus (EST-2) showed significant temporal variation; (4) juvenile and adult crabs sampled within one bay showed no size-specific differences in allelic frequencies. The spatial heterogeneity in allelic frequencies suggests that interpopulation gene flow is not sufficient to overcome population differentiation resulting from genetic drift and/or natural selection. Temporal variation in larval allelic frequencies suggests seasonal changes in larval source populations which may result from population differences in spawning season or developmental times or from seasonal changes in coastal current patterns.     

The Wahlund effect and the geographical scale of variation in the intertidal limpet Siphonaria sp.

Samples of Siphonaria sp. were collected between 1978 and 1982 from sites covering its known geographic range, from Kalbarri, Western Australia to Port Robe, South Australia. Geographic variation of 7 polymorphic enzymes was examined in this intertidal pulmonate limpet, and was found to be consistently small, indicating a large-scale influence of gene flow due to planktonic dispersal. Despite this large-scale uniformity, there is fine-scale genetic patchiness, which is repeated, rather than accumulated, on the larger scale. Throughout its geographic range, Siphonaria sp. shows deficits of heterozygotes for all 7 loci. The consistency among loci indicates that the causes of the deficits are populational, rather than locus-specific. A Wahlund effect, the departure from Hardy-Weinberg equilibrium due to mixing of individuals from groups with different allelic frequencies, is the simplest explanation of such deficits. The limited geographic variation of allelic frequencies, however, is grossly inadequate to produce these deficits through a Wahlund effect. Similarly, temporal variation in allelic frequencies in recruits does not explain the deficits. The largest contributor to a Wahlund effect appears to be binomial sampling variance among small local breeding groups. Thus, mixing of larvae on a scale of metres, rather than among geographical areas, apparently produces the deficits of heterozygotes.     

Genetic differentiation of bicolor damselfish (Eupomacentrus partitus) populations in the Florida Keys

Electrophoretic variation in proteins encoded by 23 loci revealed substantial genetic differentiation among populations of bicolor damselfish (Eupomacentrus partitus) collected from four coral reefs in the Florida Keys, USA, during 1986–1988. Genetic differentiation was concentrated between a sample collected from Little Grecian Rocks Reef (LGR) and the remaining samples, including fish from a reef only 600 m distant (Grecian Rocks Reef). Genetic distinction of the LGR sample derived from significantly heterogenous allelic frequencies at six of eight polymorphic loci. Aco-1 (aconitase); Ada (adenosine deaminase); Gpi-2 (glucosephosphate isomerase); Ldh-2 and Ldh-3 (lactate dehydrogenase); and Me-1 (malic enzyme); nevertheless, differentiation at cytosolic aconitase (Aco-1) far exceeded that observed for other loci (fixation index, F _ST=0.482), and differences in Aco-1 allele frequencies were largely responsible for large genetic distances (0.20) between LGR and the other reefs. Paradoxically, estimates of numbers of migrants exchanged between reefs per generation (mN _e=17.47) indicated the potential for extensive gene flow. The extent of genetic differentiation among these populations is evaluated relative to models of population genetic structure based on equilibrium between gene flow and natural selection or genetic drift.     

Genetic variability and differentiation of sporophytes and gametophytes in populations of Gelidium arbuscula (Gelidiaceae: Rhodophyta) determined by isozyme electrophoresis

Genetic differentiation and genetic variability of sporophytic and gametophytic populations of Gelidium arbuscula (Bory) from three localities sampled in 1989 and 1990 in the Canary Islands (Spain) were examined by isozyme electrophoresis. Twenty-three to 29 putative alleles corresponding to 22 gene loci, were compared. High deviations in Hardy-Weinberg equilibrium, and significant differences between allelic frequencies of sporophytic and gametophytic subpopulations at the same locality were found, suggesting a predominant asexual reproduction of G. arbuscula. The genetic variability (percentage of polymorphic loci, mean number of alleles per locus and average gene diversity) of haploid subpopulations was lower than that of diploid subpopulations at all three localities, being the lowest described for seaweeds. No correlation between genetic and geographical distance was found. The high genetic differentiation coefficient between all subpopulations suggests a very reduced genetic flow between subpopulations of the same and of different localities. These results suggest that the genetic structure of the populations of G. arbuscula from the Canary Islands is due to a founder-effect combined with a predominance of asexual reproduction. This is the first report comparing allelic frequencies between sporophytic and gametophytic subpopulations of seaweeds.     

Electrophoretic and biometric variability in the abyssal grenadier Coryphaenoides armatus of the western North Atlantic,eastern South Pacific and eastern North Pacific Oceans

Specimens of the abyssal grenadier Coryphaenoides armatus (Hector, 1875), from the western North Atlantic and eastern North Pacific Oceans were compared electrophoretically at 27 presumptive gene loci. At 6 of the 7 polymorphic loci there were only minor differences in allelic frequencies but a nearly fixed difference was found at one locus, phosphogluconate dehydrogenase. Eastern North Pacific grenadiers typically have a narrower interorbital space, a shorter dorsal interspace, more soft rays in the 1st dorsal fin (9–10 versus 8–9) and more pelvic fin rays (21–23 versus 18–21) than grenadiers from the western North Atlantic (as well as grenadiers from the eastern South Pacific, which were included in the biometric analysis). There is an apparent disjunction in the distribution of C. armatus in the eastern Pacific at the Gulf of Panamá which coincides with the change of morphology. It is suggested that North Pacific grenadiers comprise a subspecies, C. armatus variabilis Günther, 1878, which is morphologically distinct from the subspecies C. armatus armatus (Hector, 1875) of the other areas.     

小麦在与水杨酸诱导的应答过程中PGIP的积累

以ＳＷ８９－２５８９小麦品系为材料，利用自制的小麦抗ＰＧＩＰ血清和ｄｏｔ－ｉｍｍｕｎｏｂｉｎｄｉｎｇ ａｓｓａｙ，并结合ＰＧＩＰ粗提液对ｅｎｄｏ－ＰＧ的抑制实验，研究了小麦内源多聚半乳糖醛酸酶抑制蛋白（ＰＧＩＰ）水平与水杨酸之间的应答关系。发现用水杨酸处理过的ＰＧＩＰ粗提液在ＮＣ膜上的显色斑点颜色均较Ｈ２Ｏ处理的ＰＧＩＰ粗提液深，而且对ｅｎ－ｄｏ－ＰＧ的抑制程度也高于未用水杨酸处理的ＰＧＩＰ粗提液     

Genetic divergence of Maldivian and Micronesian demes of the damselfishes Stegastes nigricans,Chrysiptera biocellata,C. glauca and C. leucopoma (Pomacentridae)

Samples representing the damselfishes (Perciformes: Pomacentridae) Stegastes nigricans, Chrysiptera biocellata, C. glauca, and C. leucopoma from North Male Atoll, Republic of Maldives, and Guam, Southern Marianas, were surveyed electrophoretically. A sample representing C. leucopoma from Ngemelis Island, Republic of Palau, was included in the analysis to provide a within-Micronesia comparison. On average, products of 23 presumptive protein-coding loci were examined in each sample. In comparisons of Maldivian and Guamanian samples, absolute or virtually fixed allelic differences were detected at: (1) ADA ^* and PEPS ^* for Stegastes nigricans; (2) ADA ^*, AAT-1 ^*, AAT-2 ^*, and mMDH ^* for C. biocellata, and; (3) ADA ^*, AAT-1 ^*, and AAT-2 ^* for C. glauca. At three polymorphic loci, ADA ^*, sMDH-1 ^*, and sMDH-2 ^*, similar allele frequencies were found in Palauan and Guamanian samples representing C. leucopoma, suggesting that these samples share a gene pool. Significantly different allele frequencies at ADA ^* and sMDH-1 ^* and a virtually fixed allelic difference at sMDH-2 ^* were detected between the Maldivian samples and each of the Micronesian samples representing C. leucopoma. The observed patterns of allele frequency differentiation suggest that Maldivian and Micronesian samples of each of the four study species represent separate demes.