大白菜的适宜AFLP-Pst I/Mse I引物组合

基于PCR的DNA指纹鉴定技术AFLP广泛应用于生物多样性、遗传图谱构建、基因定位、分子系统发育和品种鉴定等方面.为了筛选出大白菜适宜的AFLP引物组合,研究以抗根肿病大白菜双单倍体CR Shinki、感病自交系94SK及其后代F2构成的纯合抗病和纯合感病DNA混合池为材料,利用256对Pst I/Mse I引物组合进行了AFLP分析.结果表明:平均每个组合检测到55条带,共扩增13 079条带,平均每1 000条带检测到1.30个根肿病抗性基因连锁标记;多态性带数为3 167条,双亲间多态性频率约为0.24;扩增带数与多态性带数呈线性正相关,引物组合中的不同GC含量与扩增带数和多态性带数存在显著性差异,并表现出线性负相关.筛选出的适宜53对引物组合共扩增出4 381条带,占总扩增片断的33.50%,平均每对扩增出83条,其中9个组合扩增出与抗根肿病基因连锁标记.     

葎草DNA的提取及AFLP标记反应体系的建立

本文对CTAB法、改良CTAB法和SDS法提取雌雄异株植物葎草(Humulus scandens L.)基因组的方法进行了比较分析,并在此基础上对影响葎草AFLP扩增的关键因素模板浓度、酶切时间、选择性扩增模板浓度进行了优化.结果表明,改良的CTAB法更适合葎草基因组DNA的提取;同时利用AFLP分子标记技术,采用EcoI-Mse I酶切组合,共筛选27对引物组合,确定了适用于葎草AFLP反应的最佳酶切连接、预扩和选扩体系.同时发现2对引物组合E-ACG M-CTA和E-AAC M-CAC共扩增出5条雌雄性别特异条带.     

大豆RN型细胞质雄性不育系及保持系cDNA-AFLP分析

本研究利用cDNA-AFLP技术对大豆RN型细胞质雄性不育系及其同核异质保持系进行多态性分析。提取不育系和保持系的总RNA,反转录成cDNA。以cDNA为模板,通过PCR对64对AFLP引物进行扩增筛选,对不育系或保持系中特有的差异带进行回收测序,通过NCBI-Blast同源比对分析得到12条同源序列,其中8条序列为已知功能的基因,4条为未知功能基因。其中与线粒体基因同源的序列A4,编码ATP合成酶γ亚基蛋白基因同源的序列A1,编码减数分裂不联会突变蛋白同源的序列B1可能与不育有关。这些片段的发现为不育机制的深入研究提供帮助,同时可作为不育系及保持系快速鉴定的依据,对缩短育种年限,加快育种进程具有重要意义。     

应用AFLP技术检测水稻遗传多样性的研究

利用扩增片断长度多态性（Amplified fragment lenth polymorphism简作AFLP)分子标记技术研究了23个水稻品种的遗传多样性从49对AFLP引物中筛选出4对多态性高，分辨能力强的引物。4个AFLP引物组合分别扩增出43、37、49、33条多态性带，平均每个引物组合扩出40．5条多态性带，4个引物组合共扩增出246条带。利用AFLP数据进行聚类分析，将23个品种聚为10个类群，结果表明，AFLP在水稻类群划分的应用是可行的。     

AFLP在水稻类群划分研究中的应用

利用AFLP分子标记技术研究了22个水稻品种的遗传多样性，从49对AFLP引物中筛选出了4对多态性高，分辨能力强的引物，4个AFLP引物组合分别扩增出43、37、49、33条多态性带，平均每个引物组合扩出40．5条多态性带，4个引物组合共扩增出246条带。利用AFLP数据进行聚类分析，将22个品种聚为8群，结果表明，AFLP在水稻类群划分的应用是可行的。     

野生榆叶梅遗传多样性的AFLP分析

本研究利用AFLP分子标记技术,对野生榆叶梅6个居群进行分析.利用已筛选出的8对引物组合进行扩增,共产生256条谱带,其中206条谱带具有遗传多态性,占总谱带的80.47％;平均每对引物组合扩增产生129条多态条带,平均多态率为50.26％.6个居群观察等位基因数Na平均值为1.502 6,总Na值为1.804 7;有...     

甜瓜雌雄异花同株近等基因系的构建及近等性评价

雌雄异花同株类型在甜瓜杂交制种时可部分免除人工去雄,确保杂交种纯度,所以,对杂种优势利用中有着重要价值.为了研究和利用控制甜瓜雌雄异花同株基因A,用雌雄异花同株材料Mr作母本P1,雄花两性花材料Mm作父本P2,用P1做轮回亲本与F1杂交,经连续回交并最终自交纯化,获得雌雄异花同株近等基因系(BC6F4).用形态相似法和AFLP标记对获得的近等基因系和轮回亲本进行分析,结果表明:(1)Mr xMm的F2与BC6S1分离群体中,雌雄异花同株株数与雄花两性花株数符合3:1比例,回交群体中雌雄异花同株株数和雄花两性花株数符合1:1的比例;在发育期、果皮色、网纹等农艺性状上没有明显差异;(2)用448对AFLP引物检测轮回亲本和近等基因系之间多态性,有417对引物没有多态性,31对有多态性,统计得其遗传相似系数为99.73%;(3)平均每个AFLP引物对可扩增出46.8条带,说明AFLP揭示的遗传信息量很高,是一种评价近等性较理想的分子标记,这与以往结果一致.     

AFLP分析小豆种(Vigna angularis)内遗传多样性

利用12对AFLP引物,对来自于世界6个国家的146份小豆(Vigna angularis)栽培变种(var. angularis)和野生变种(var. nipponensis)种质的基因组DNA进行扩增,得到580条清晰的显带,其中313(53.93%)条呈多态性,平均每对AFLP引物得到26.08条多态性带;平均遗传距离0.35,变异幅度为0.00～0.87.利用AFLP多态性数据进行的Jaccard''s遗传距     

一个与亚洲百合无花粉性状紧密连锁的SRAP标记

为了探讨亚洲百合无花粉性状的分子遗传机制,筛选与该性状紧密连锁的分子标记,实现分子辅助选择。本研究以无花粉与有花粉亚洲百合杂交创制的F1单株为试验材料,采用BSA法,对亚洲百合无花粉性状进行SRAP标记分析。在无花粉基因池和有花粉基因池之间共筛选了108对SRAP引物组合,获得了1对在两基因池间扩增存在显著差异的引物组合EM2/ME3,并成功对两基因池间扩增出的差异片段进行回收、克隆和测序,得到了该片段375 bp的碱基序列,并将该特异标记命名为E2M3-375。     

西瓜种质资源的遗传多样性及亲缘关系的AFLP分析

利用AFLP指纹图谱分析技术对57个西瓜材料进行了基因组DNA多态性分析.结果表明,18对AFLP引物共产生709条DNA带,平均每个引物组合扩增出39.4条带,其中440条为多态性带,占总带数的61.4%;根据DNA谱带计算品种间遗传相似系数,其变化范围在0.24～0.99之间,平均相似系数为0.70,说明西瓜品种间遗传基础狭窄.用NTSYS软件进行聚类分析,57个西瓜品种被划分为2个类群.其中类群1包括1个野生西瓜,类群2均为栽培种.在类群2中引进的资源聚在一起,杂交种和双亲或其一聚在一起.此外,本研究表明,AFLP指纹分析技术具有很高的分辨率,能够揭示西瓜品种间的差异,是鉴定西瓜品种的有力工具.     

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.     

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.     

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.     

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...