濒危珍稀植物半枫荷转录组中SSR位点分析

分析半枫荷转录组中的SSR位点信息,并设计简单重复序列(SSR)引物,以期为半枫荷EST-SSR分子标记提供有力工具。利用MISA工具筛选了半枫荷转录组测序获得的77629条Unigenes,对其SSR位点信息进行了分析;在此基础上利用Primer 3.0设计SSR引物,并随机选择50对SSR引物对4株不同来源的半枫荷进行多态性扩增分析。在半枫荷的转录组中,共找到15041个SSRs,分布于10669条Unigenes,SSR位点发生频率为13.74%,含多个位点的序列数为3114,占SSRs位点总数的29.19%,以复合形式出现的位点数2044个,占SSRs位点总数的19.16%,SSRs的平均距离是3.2 kb。SSRs位点中二碱基重复是主要类型,占总SSRs的42.17%;其次是单碱基重复基序(38.25%)SSRs。所包含的重复基元中,单碱基重复基元A/T(5572),二碱基重复基元AG/CT(4845)是优势重复基元类型,分别占总SSRs的37.05%、32.21%。利用Primer 3共设计出28590对SSR引物。随机选择50对引物进行PCR扩增,其中44对(88.0%)扩增出清晰、可重复的条带,15对(34.1%)扩增条带表现出多态性。半枫荷转录组SSR位点出现频率高,类型丰富;大量的SSR为其遗传多样性分析、分子标记辅助育种和遗传图谱构建提供了丰富的候选分子标记。     

基于菜心(Brassica campestris)基因组Survey测序开发多态性SSR标记

为解决菜心SSR标记数量不足、已开发的位点多态性差等问题,本研究利用高通量测序技术,对‘四九-19’和‘3T6’两份菜心材料进行基因组Survey测序,规模化开发多态性SSR标记。两个菜心材料分别获得55 649 657个和59 300 433个Clean reads,分开拼接组装得到430 483个和499 876个Contig。在两个材料的Contig中搜索到共有的SSR位点为30 696个,其中以二和三核苷酸重复基序最为丰富,占总SSR位点的67%。分析比较发现,3 652个(12%) SSR位点在两份测序材料间具有潜在多态性,随机挑选50个SSR位点进行PCR扩增验证,48对(96%)引物在4份菜心材料中扩增出清晰的条带,其中31对(62%)引物在两份测序样品间具有多态性,19对(38%)引物在另两份菜心材料间具有多态性。结果表明,利用基因组Survey测序能开发SSR标记和开发具有多态性的SSR标记,本研究开发的多态SSR标记将进一步为菜心分子标记的发展和应用提供基础。     

基于白木香转录组的SSR序列特征分析

为探究白木香的简单重复序列特征,开发SSR分子标记用于白木香种质资源的遗传分化和分子鉴定,本研究鉴定了白木香转录组unigene序列的SSR位点,对其SSR的分布及序列特征进行统计分析,进而设计SSR引物,并验证其SSR引物的多态性。结果表明,在128 712条unigene中共鉴定到9 362个SSR位点,分布频率为7.27%。SSR序列中双碱基重复序列最多,占总SSR的54.90%;白木香双碱基重复序列以AG/CT、AC/GT为主,占34.22%。SSR位点重复次数主要集中在5～11次,占总SSR位点数的96.56%,其中三碱基重复5次的SSR位点数最多,共有1 925个。设计并合成50对引物,其中35对引物可扩增出预期大小条带,扩增效率达到70%。以24个不同白木香个体对35对引物进行扩增,采用8%非变性聚丙烯酰胺凝胶电泳检测SSR引物多态性,表明SSR引物具有多态性。研究表明,白木香转录组SSR重复基元类型丰富,分布密度高,多态性高,可用于白木香资源的遗传多样性评价、遗传分化、种质鉴定和分子育种等后续研究。     

基于红掌转录组序列的SSR标记分析与开发

本研究从红掌转录组共32 391条unigenes中搜索得到3 944个SSR位点,出现频率为12.17%。EST-SSR类型以一、二、三核苷酸重复为主,占总SSR比例的96.29%,其中二核苷重复为主要基序类型,占总SSR的51.01%,AG/CT重复类型出现最多。设计合成的200对SSR引物中有22对引物扩增条带清晰、多态性好,在18个红掌品种中得到有效性验证。结果表明,基于红掌转录组序列的SSR标记开发是可行的,这些EST-SSR的开发可为红掌遗传多样性分析、分子育种等奠定重要基础。     

苦荞全基因组SSR位点特征分析与分子标记开发

目前苦荞SSR多态性标记数量较少,根据已发表的苦荞基因组测序数据,利用MISA软件对1~6核苷酸重复的SSR位点进行了查找和序列特征分析,批量设计引物并对引物进行了有效性和多态性检测。结果表明,苦荞基因组中共检测到1 640个SSR位点,其中三核苷酸重复型SSR最多,占比63.29%,五核苷酸重复型最少,仅占0.12%。AT/TA、AAG/CTT、ACC/GGT和ATC/GAT为出现频率较高的重复基序。苦荞基因组SSR序列长度变化范围为12~476bp,平均长度23.14bp,长度12~19bp的占比71.71%,长度≥20bp的占比28.29%。根据不同类型SSR位点设计并合成引物479对,选择200对引物对5份苦荞资源和3份甜荞资源进行多态性检测,有56对扩增出多态性条带,17对在苦荞种质中产生多态性条带,48对在甜荞种质中产生多态性条带,9对同时在两种种质中产生多态性条带。利用苦荞全基因组序列可实现SSR标记的批量开发,可鉴定出适用于苦荞和甜荞遗传多样性分析、遗传图谱构建和品种鉴定等研究的SSR引物。     

基于丝瓜全基因组序列SSR分子标记开发

为研究高效的丝瓜分子标记,本研究根据已报道的有棱丝瓜和普通丝瓜全基因组序列信息,利用MISA 2.1软件对丝瓜全基因组水平的SSR位点进行搜索,分别在有棱丝瓜和普通丝瓜中鉴定到341 829个和348 397个SSR位点,发生频率分别为2.20 kb/SSR和2.03 kb/SSR。有棱丝瓜和普通丝瓜重复单元最多的均为单核苷酸,分别占总数的73.90%和74.21%,其次为二核苷酸和三核苷酸重复单元。在有棱丝瓜和普通丝瓜中各鉴定到211种SSR重复基序,其中A/T、AT/AT、AG/CT和AAT/ATT重复基序类型出现频率最高。优选SSR位点,分别在有棱丝瓜和普通丝瓜中开发了278 522和284 966对SSR引物。通过比对两个基因组的SSR引物序列与自身的参考基因组,获得在有棱丝瓜和普通丝瓜中具有序列大小差异的SSR引物955对,随机挑选其中64对引物在6份表型差异较大的丝瓜材料中进行引物有效性检测,其中61对引物有目的条带扩出,16对引物具有多态性。本研究在丝瓜全基因组水平所开发的SSR分子标记可为后续丝瓜种质资源鉴定、亲缘关系分析及分子标记辅助育种提供基础。     

基于荧光标记的茶树花转录组序列SSR标记开发

本研究对204 199条茶树花转录组Unigenes进行SSR简单重复序列的查找,得到含有SSR的序列60 581个,出现频率为29.67%。EST-SSR重复类型以单核苷酸和二核苷酸为主,占总SSR比例的85.69%,其中主要重复基序类型为单核苷酸,占总SSR的47.97%,A/T重复类型出现最多。采用荧光标记PCR技术对设计合成的100对SSR引物进行引物筛选,其中有28对引物扩增条带清晰、多态性好,在4个品种的茶树花中得到有效性验证。结果表明,茶树花转录组的SSR标记开发是可行的,这些EST-SSR的开发对茶树花遗传多样性分析、分子育种和开发茶树不育相关的SSR标记等具有重要意义。     

基于转录组测序的黑枣EST-SSR引物开发与鉴定分析

目前黑枣已有的分子标记比较匮乏,本研究基于转录组测序技术对黑枣品种进行SSR引物开发,为黑枣种质资源评价及分子标记辅助育种提供有力的技术支持。本研究对‘冀洪1号’黑枣转录组序列进行了分析筛选和开发,并利用开发出的引物进行了验证分析。结果表明:共得到52 537个Unigene序列,SSR位点总数22 327个,包含SSR的Unigene序列数为15 286条。黑枣SSR位点的重复单元中,二核苷酸重复类型的SSR最多(52.26%),其次为单核苷酸(25.84%)及三核苷酸(19.25%)。随机挑选90对EST-SSR引物进行验证,有效扩增率为77.78%(70对),多态性引物比例为18.57%(13对),对13个多态性位点进一步分析可得,共扩增了35个等位基因,PIC值介于0.233~0.677之间,平均为0.430。本研究开发出的EST-SSR分子标记,为后期进行黑枣良种的鉴别及分子育种提供了分子技术手段。     

基于甘草全基因组序列的SSR分子标记开发

由于不同基原和产地的甘草有效成分差异较大,开发甘草特异分子标记对于种质资源鉴定意义重大。本研究以甘草全基因组序列为基础,检测到193 207个SSR位点,发生频率为73.52%。单核苷酸重复类型最多(60.73%),其次为二核苷酸(26.11%)和三核苷酸重复单元(10.95%)。分析重复序列位点发现,甘草SSR中包含284种类型重复基元,具有碱基偏好性,主要以A/T为主要重复单元,优势基元依次为A/T (58.28%)、AG/CT (10.48%)、AT/AT (10.48%)、AC/GT (5.12%)、AAT/ATT (3.57%)。优选140 294个重复位点设计出701 302对SSR引物,随机选取100对引物进行有效性检测,63对引物均扩增出目标条带,其中,12对引物能在材料间扩增出特异性条带,可用于对不同产地甘草进行区分。本研究开发的大量SSR标记不仅可用于甘草种质资源的鉴定分析,也将用于进一步的甘草分子标记辅助中。     

基于油楠(Sindora glabra)转录组测序的SSR分子标记的开发

油楠(Sindora glabra)作为极具开发潜力的能源植物,在分子水平上的研究仅局限于ISSR分子标记。本研究利用Trinity软件对油楠转录组数据进行组装,共得到总长为48307806 bp的283998条Unigenes。利用MISA软件寻找到97443个含有SSR的重复基元。SSR位点中主要重复序列为单核苷酸和二核苷酸,分别占总SSR位点的67.68%和22.56%,其次是三核苷酸,占8.54%。利用Primer 3.0设计引物,并从中随机选择200对引物进行PCR扩增,其中有13对扩增出清晰条带,多态性高,重复性好。油楠SSR分子标记的开发对于研究其遗传多样性、重要性状基因定位及分子标记辅助选择育种等起到重要的推动作用。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.     

Genetic variation for disease and nematode resistances and forage quality in perennial diploid and tetraploid lucerne populations (Medicago sativa L.)

Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality.     

Review of Effects of Active Components of Gastrodiae Rhizoma on Central Nervous System

In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,...     

Effects of Pb on Rhizosphere Soil Enzyme Activity and Chemical Constituents of Achyranthes bidentata Blume

[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat...     

不同P-Zn配比对小麦幼苗微量元素营养的影响

采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.