人工合成六倍体小麦的ISSR位点遗传多样性分析

为了解人工合成六倍体小麦品种的遗传多样性,选用了100条ISSR引物对11份人工合成小麦和3个普通小麦材料(TP、HTS-1、CS)进行了遗传多样性分析。筛选出了42条引物可用于遗传多样性分析,其中有24条引物对供试材料具有较强的鉴别能力。42条引物共扩增出了273个条带,每条引物扩增出的条带数是3~12,平均每条为6.5,同时检测到在14份小麦试材中有170(占62.3%)个等位变异位点,引物等位变异数为1~11,平均每个位点出现4.5个等位变异。42条引物扩增产物的多态性信息量(PIC)为0.499~0.879,平均为0.767,多数引物扩增的多态性信息量在0.800左右。14份材料间的遗传相似系数为0.663~0.934,平均为0.790。根据材料间的遗传相似系数聚类,14个材料被聚为3类,其中聚为第2类的试材最多。本研究表明,14份小麦材料遗传相似性较大,亲缘关系较近,但参试材料总体遗传多样性水平较高。聚类分析结果与试材系谱及亲本来源相吻合。结果表明ISSR标记技术可应用于物种的鉴别、遗传多样性研究和遗传图谱构建。     

洋葱种质资源遗传多样性的ISSR分析

应用ISSR标记对32份洋葱种质资源的遗传多样性进行了分析。从31个ISSR引物中筛选出4条扩增产物条带清晰、多态性高的引物,在32份资源样品中共扩增出39条带,其中31条带为多态性位点,平均每个引物扩增的多态带数为7.75条,多态性条带比率（PPB）为79.48%。资源间的遗传相似系数在0.552~0.960之间,具有较为丰富的遗传多样性。ISSR聚类分析表明,在L取值为D=0.68时,可将32份洋葱资源分成5类：第一类包括18份种质资源,主要以Yellow Sweet Spanish系统为主;第二类包括1份种质资源,为Bejo Daytona;第三类包括3份种质资源,为Yellow Globe系统;第四类包括9份种质资源,为Yellow globe danvers系统;第五类包括1份种质资源,为Yellow Danvers system系统。较好地揭示了洋葱种质资源间的遗传多样性与亲缘关系,可为洋葱遗传育种和杂交亲本选择提供科学依据。     

基于ISSR标记分析豌豆农家品种遗传多样性

为掌握内蒙古部分地区种植的农家豌豆品种的亲缘关系,本研究通过ISSR分子标记技术,对来自内蒙古自治区部分地区及甘肃省张掖市的29份豌豆农家品种的遗传多样性进行分析。结果显示,从19个ISSR引物中筛选出多态性明显、条带清晰、反应稳定的引物共7个。29份DNA材料共扩增出118条条带,其中116条为多态性条带,平均每个引物扩增出的条带数为16.9条,多态性比率为98.31%。Shannon多样性指数平均为0.505 9,每个位点的有效等位基因数为1.569 6,品种间遗传相似系数变幅为0.370 4～0.928 6,表明本研究的29个豌豆农家品种具有丰富的遗传多样性。利用UPGMA聚类分析,以遗传相似系数0.69为界限,将29份材料划分为5类,聚类结果与豌豆种群地域性分布规律关联性较高,表明ISSR分子标记技术的遗传多样性分析能够将地理来源相近的居群进行聚类划分,其研究结果可运用于豌豆种质资源保护及育种工作中。     

利用ISSR标记解析黔东南玉米地方种质的遗传多样性

采用ISSR标记技术对来自贵州省黔东南州的43份玉米地方种质遗传多样性进行了评价.结果表明,用筛选出的17条引物进行PCR扩增,共扩增出清晰、重复性好的谱带261条,其中257条具有多态性,多态性比率为98.5%.品种间遗传多样性分析表明,其遗传相似系数变化范围为0.579～0.828.以ISSR构建的指纹图谱表明,其中有2条引物能有效地将43份玉米资源完全区别.表明贵州省黔东南州地方玉米种质间存在着丰富的遗传多样性.     

新疆薰衣草种质资源遗传多样性的ISSR分析

本研究应用ISSR标记对19份薰衣草种质的遗传多样性进行分析。结果显示:从100条引物中筛选出9条多态性明显的引物,19份材料DNA共扩增出94条谱带,其中多态性谱带40条,多态性比率为42.6%,平均每个引物扩增条带数为10.4条;9条ISSR引物可将所有样品完全分开,当遗传相似阈值为0.69时,可将样品分为3个类群:第Ⅰ类群13个品种(系)可分为2个亚类,第Ⅱ类群5个品种(系)可分为2个亚类,第Ⅲ类群1个品种(系)。样品间的遗传相似性系数为0.325~0.975(平均0.737)。群体的有效等位基因数、基因多样度、Shannon信息指数分别为1.454 0、0.280 5和0.435 4。研究结果表明,19个新疆薰衣草种质资源遗传多样性水平处于较高。     

基于ISSR标记的福建茶树品种(系)遗传多样性分析

本研究通过对所收集的55份福建茶树品种(系)进行遗传多样性和亲缘关系分析,采用ISSR分子标记技术进行扩增,并通过NTSYS-pc2.10e软件进行数据分析。以7份福建茶树品种为材料,对50条通用引物进行筛选,得到多态性好、扩增条带清晰的引物15条。15条引物共扩增出213条条带,208条为多态性条带,多态性所占比率为97.65%。55份茶树资源遗传相似系数介于0.54~0.91之间,表明这55份茶树遗传背景差异较大。并根据ISSR扩增图谱构建了遗传聚类图,明确了各茶树品系与品种间的亲缘关系,为茶树培育新品种奠定科学基础、提供理论依据。     

斑茅野生种质资源遗传多样性的ISSR分析

斑茅具有抗病、抗虫、抗逆等有利基因,是甘蔗遗传改良的重要种质资源,为了对斑茅的遗传多样性进行鉴定,本研究运用ISSR分子标记的方法对24份斑茅无性系材料的遗传多样性进行鉴定,结果表明:14个ISSR引物共扩增出210条带,其中多态性条带为201条,多态性百分率为95.71%;24份材料的Nei指数(h)介于0.30~0.79,遗传相似系数集中在0.3~0.5之间;基于UPGMA聚类分析,在遗传距离0.77处,可以将24个材料分成5个类群,在24份材料中找到44条特异带;说明斑茅有着相对丰富的遗传多样性,能够广泛用于甘蔗的遗传育种改良。     

马铃薯不同品种(系)遗传多样性的ISSR分析

本研究运用ISSR分子标记技术对30份马铃薯品种(系)材料进行多态性和聚类分析,分析各品种(系)间亲缘关系。结果表明:从56条ISSR引物中筛选出6条引物进行PCR扩增,共扩增出52条带,多态性条带为47个,多态性比率约为90.38%。通过UPGMA法对30份马铃薯品种(系)材料聚类分析显示,30份供试材料品种间遗传相似系数为0.40~0.95,平均相似系数为0.675;在相似性系数0.75附近,30份马铃薯品种(系)可分为6个大类,包括5大复合组和1个独立类。这些结果说明所选取的30个马铃薯品种(系)的遗传差异比较大,遗传多样性较丰富;该研究结果为马铃薯的遗传多样性利用及种质鉴定和杂交育种提供了有力的理论依据。     

应用ISSR分子标记绘制红麻种质资源DNA指纹图谱

以6份红麻种质资源为材料, 对UBC807~UBC80等80个ISSR引物进行筛选, 筛选出多态性好的ISSR引物20个。利用这20个ISSR引物扩增来自国内外84份红麻种质资源, 共获得230条谱带, 平均每个引物扩增出11.5条谱带, 其中多态性谱带185条, 多态性条带比率为80.43%, 表明供试的红麻种质资源遗传多样性较丰富。以供试84份红麻种质资源的ISSR扩增谱带为基础, 建立了供试材料扩增条带指纹数据库的Excel文件。根据指纹图谱唯一性原则, 采用自行开发的DNA指纹数据分析软件, 再从20个多态性好的ISSR引物中遴选出UBC 813、UBC 825、UBC 836、UBC 888和UBC 889引物, 绘制出82个红麻种质资源的DNA指纹图谱, 为红麻种质资源分子身份证的构建奠定了基础。     

古茶树种质资源遗传多样性ISSR分析

为了解贵州三都水族自治县古茶树的遗传多样性,本实验采用ISSR分子标记对145份古茶树的遗传多样性和亲缘关系进行分析。从100条ISSR通用引物中共筛选得到15条多态性好、可重复、扩增清晰的引物,利用筛选到的引物对供试的古茶树基因组DNA进行扩增。结果表明,15条引物共扩增出116条带,其中多态性条带有110条,平均多态性条带比率为94.37%。利用Popgene 32软件计算145份古茶树材料的平均观察等位基因数(Na)为1.945 7,平均有效等位基因数(Ne)为1.529 3,平均Nei’s遗传多样性指数(He)为0.312 6,平均Shannon信息多样性指数(I)为0.471 2,遗传一致度为0.448 3～0.965 5。采用NTSYS-pc 2.1软件构建UPGMA聚类图,在相似系数为0.72时,将145份供试古茶树材料分为四大类,聚类结果与形态学聚类结果相符。该研究为古茶树种质资源的保护、利用及良种培育提供理论依据。     

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.     

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.     

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.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

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...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...