芦苇根尖体细胞的染色体数目和形态

本文研究了芦苇(Phragmites communis)幼苗根尖分生组织细胞的染色体数目和形态。其染色体数为2n=96。在有丝分裂中期染色体组中,染色体的大小逐渐地改变,按照染色体的大小和形态,96个染色体能被分成8个同源单倍体染色体组。每一组由11个中部着丝点染色体和1个亚中部着丝点染色体组成。     

芦苇根尖体细胞的染色体数目和形态

本文研究了芦苇(Phragmites communis)幼苗根尖分生组织细胞的染色体数目和形态。其染色体数为2n=96。在有丝分裂中期染色体组中,染色体的大小逐渐地改变,按照染色体的大小和形态,96个染色体能被分成8个同源单倍体染色体组。每一组由11个中部着丝点染色体和1个亚中部着丝点染色体组成。     

中国部分牦牛品种线粒体DNA遗传多态性研究

采用DNA测序技术首次测定了中国5个牦牛品种(类群)35个个体线粒体DNA控制区(D loop)全序列,结果表明:牦牛线粒体DNA控制区全序列长度为891～895bp,T、C、A、G4种核苷酸的含量分别为28.5%、25.3%、32.5%、13.7%。检测到55个变异位点,约占分析位点总数的6.16%,核甘酸变异类型有转换、颠换、插入/缺失4种。确定了24种单倍型,单倍型H4和H6为中国牦牛的主体单倍型,各单倍型在品种间分布不平衡,所测定的5个牦牛品种(类群)单倍型多样度平均为0.9697±0.0180,说明我国牦牛D loop单倍型类型丰富。牦牛品种内各序列平均核苷酸差异数为10.936,核苷酸多样度为1.231%;牦牛品种间核苷酸分歧度(Dxy)约为0.760%～2.155%,品种间双参数距离范围为0.000～0.029,表明我国牦牛遗传多态性丰富。对D环序列变异的分子方差分析和单倍型网络关系图的结果表明:我国牦牛品种间出现显著的遗传分化,牦牛单倍型网络关系图聚为2个聚类簇,表明我国牦牛有2个母系来源,或者有2个主要的驯化地点。     

月季种质资源的倍性变异及核型多样性研究(英文)

采用常规压片法对包括5个蔷薇野生种、8个古老月季及9个现代月季品种共22份月季种质资源进行核型分析。供试材料共有3种不同倍性:5个野生种中粉团蔷薇为三倍体(2n=3x=21),其他4个材料为二倍体(2n=2x=14);9个现代月季品种均为四倍体(2n=4x=28);而古老月季品种中包含二、三、四倍体3种倍性。22份材料中共发现4种不同类型的核型,在野生种中为1A、2A;古老月季中为1A、2A、1B;现代月季中为1A、1B、2B。另外,供试材料在核不对称系数、着丝粒指数、随体数目及位置、染色体相对长度组成等方面差异较大,说明在月季种质资源中存在着丰富的核型多样性。     

贵州布依族、仡佬族、仫佬族、毛南族、壮族Y-SNP的初步研究

为分析贵州布依族、仡佬族、仫佬族、毛南族、壮族父系遗传结构, 探讨其起源及迁徒。通过聚合酶链式反应-限制性内切酶长度多态性(PCR-RFLP)方法检测贵州境内5个民族10个SNP位点构成的Y染色体单倍型, 并以省内苗族为对照分析其父系遗传结构。结果显示5个民族集中于Y-SNP中H8单倍型, 苗族样本集中于Y-SNP中的H8、H11与H12单倍型。说明贵州省布依族、仡佬族、仫佬族、毛南族、壮族5个民族之间有密切联系, 且与国内其他地域有较大的遗传差异, 是一个相对独立的群体。     

芦苇细胞培养中的染色体稳定性及诱变效应

培养一年后的芦苇愈伤组织中,仍以80％的八倍体细胞占绝对优势。染色体数目变异范围在105—26之间。而EMS处理的愈伤组织与末经处理的愈伤组织相比较,明显地具有比较高的染色体数目变异和倍性变异。     

山东汉族人群中13个快速突变(RM)Y-STR基因座的多态性

本研究旨在调查13个快速突变Y染色体STR基因座(RMY-STR)在山东汉族人群中的等位基因频率以及遗传多态性。采集154个山东无关男性个体FTA卡血液样本。采用13个RMY-STRPCR复合扩增体系进行扩增以及AB3130XL遗传分析仪进行Y-STR分型,并对分型结果进行相关统计,检测13个RMY-STR位点遗传多态性分布。本研究在13个基因座上共检测出331个等位基因,基因型多态性(GD)分布在0.7643(DYS576)~0.9946(DYF399S1abc)之间。通过13个RMY-STR基因座在154名山东汉族男性无关个体中共检测出154种单倍型,无共享单倍型现象出现。总的单倍型多样性(HD值)为1,识别能力(DC值)为1。故13个RMY-STR基因座组成的分型系统在山东汉族人群中表现出很强的个体识别能力,具有重要的法医学应用价值。     

应用Y染色体SNP对新疆三个隔离人群遗传多样性的研究

克里雅人、罗布人、刀郎人是生活在我国西部边疆沙漠腹地、人口稀少的隔离人群。基于对这三个隔离人群179人Y染色体全序列的测序和分型,得到每个个体Y染色体所有突变的SNP位点和隶属的单倍群,并对各单倍群类型和频率进行了分析。以探知三个隔离人群的Y染色体遗传结构和遗传多样性。通过研究结果表明:克里雅人群检出12个单倍群,高频单倍群有J2a1b1(25.64%),R1a1a1b2a(20.51%),R2a(17.95%),R1a1a1b2a2(15.38%);罗布人群检出16个单倍群,高频单倍群有J2a1(43.75%),J2a2(14.06%),R2(9.38%),L1c(7.81%);刀郎人群检出40个单倍群,高频单倍群有R1b1a1a1(9.21%),R1a1a1b2a1a(7.89%),R1a1a1b2a2b(6.58%),C3c1(6.58%).三个隔离人群与维吾尔族、蒙古族、撒拉族亲缘关系较近;在单倍群类型和频率上与维吾尔族最接近且无显著性差异(f=0.833,p=0.367)。此外,三个隔离人群单倍群类型和频率显示明显的亚欧混合现象,经过长期基因融合使其具有中亚人群的典型特征,适用于法医遗传学。     

DYS458、DYS534、DYS426和DYS626基因座多态性研究

目的：研究河南汉族群体DYS458、DYS534、DYS426和DYS626四个Y-STR基因座遗传多态性,评估其法医学应用价值。方法：采用PCR扩增和非变性聚丙烯酰胺凝胶电泳及DNA测序分析河南汉族113名无血缘关系、健康男性个体的4个Y-STR基因座基因及单倍型频率分布。结果：4个基因座共发现了24个等位基因,频率分布在0.0177～0.9027,基因多样性（gene diversity,GD）值最低为0.1801（DYS426）,最高为0.8368（DYS626）。113个个体共检测到94个单倍型,其79种为惟一的,单倍型多样性为0.99589。结论：4个Y-STR基因座在河南汉族群体均具有较高的遗传多态性,可应用于法医学个体识别和亲子鉴定。     

扎龙芦苇遗传多样性ISSR分析

采用ISSR分子标记技术对扎龙湿地的5个野生芦苇居群进行了遗传多样性研究.从75条ISSR引物中筛选出10个特异性强、稳定性好的引物进行ISSR分析.共获得96个位点,其中多态位点94个,多态位点百分率为97.92％.PopGene分析结果表明:居群的平均多态位点百分率为56.46％,Shannon's多样性指数(J)...     

Morphology and Genetic Diversity of Phragmites australis in Beijing

为探明北京地区芦苇(Phragmites australis)的资源状态和多样性, 实地考察北京主要河流、湿地和水库, 发现北京地区芦苇总生长面积已超过600 hm²。芦苇染色体倍性以八倍体为主, 四倍体次之。在面积较大的湿地内, 八倍体单一芦苇群落占据优势地位; 而在城市的浅河内有形态和遗传性多样的混合种群。研究表明, 植物性状和倍性水平之间无显著相关性。在小清河发现了6种形态各异的芦苇克隆, 均属于叶绿体DNA片段的P单倍型; 其单倍体基因组大小为(0.499±0.019) pg, 变异系数为3.8%。这表明表型与单倍型之间也不具相关性。此外, 发现1个具有变叶特性的芦苇, 将其命名为金条芦苇。北京地区芦苇形态和遗传多样性为研究芦苇基因型与环境适应性之间的关系提供了珍贵的资源。     

Cryptic lineages and potential introgression in a mixed-ploidy species (Phragmites australis) across temperate China

Polyploidization and hybridization are very common in natural plant species, and mixed-ploidy species provide a unique opportunity to study the effects of evolutionary history, local abundance, and ploidy level on the direction and extent of introgression between intraspecific lineages. First, we delimited two morphologically cryptic lineages of Phragmites australis Trin. ex Steud. in temperate China using 11 nuclear microsatellites and two chloroplast DNA fragments with 225 samples from China as well as 11 samples from Oceania and Europe. Our evidence supported that haplotype O and haplotype P were two relatively independent lineages with low and high ploidy levels, respectively; haplotype M might be ancient and could have undergone a complex evolutionary history. Then we examined the lineage divergence and compared the introgression patterns between two major lineages along geographical and abundance gradients with a large number of samples (n = 1067) collected from China. The sympatric coexistence of two lineages in north and northeast China implies an ongoing or potential introgression between them. Cline analysis showed that the level of genetic admixture were significantly correlated with longitude rather than latitude. Our results also suggested that ploidy level could deeply influence the introgression asymmetry, and the effect of the current local abundance on introgression might be covered by the past coexistence time driven by phylogeographic history. Our study draws a baseline for future research on the ecological and evolutionary consequences of migration and introgression of Chinese P. australis under global change.     

Pyrosequencing Reveals Bacterial Diversity in the Rhizosphere of Three Phragmites australis Ecotypes

Here we present the use of high-throughput DNA pyrosequencing to assess bacterial diversity in the rhizosphere of three Phragmites australis ecotypes from the Hexi Corridor, China. In total, 43404 sequences were obtained for the three ecotypes, representing 31 phyla and a small amount of unclassified bacteria. The predominant bacterial groups in the rhizosphere of P. australis were Proteobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Gemmatimonadetes and Planctomycetes. The bacterial community structure varied with the different degrees of wetland degradation, which were exhibited by the three P. australis ecotypes in the study area. At the phylum level, the Caldiserica, Chlamydiae, Deferribacteres, Lentisphaerae, and candidate division WS3 were only detected in the swamp reed (SR) sample. Then, δ-proteobacteria, Acidobacteria, Cyanobacteria and Fusobacteria decreased, the Actinobacteria increased with the degree of degradation from SR through salt meadow reed (SMR) to dune reed (DR). The functional bacterial genera also varied with wetland degradation. The sulfur and sulfate-reducing, nitrifying and nitrogen-fixing bacteria were more abundant in the rhizosphere of the SR sample. Methane-oxidizing bacteria were abundant in the SR and DR samples but less so in the SMR. In our study, pyrosequencing of different P. australis ecotypes provided insight into the structural variation of the rhizosphere bacterial community. This study gave a database for the use of bacteria in the protection and ecological restoration of wetland.     

Flow cytometric assessment of cytotype distributions within local populations of Phragmites australis (Poaceae) around Lake Biwa,the largest lake in Japan

Phragmites australis (Poaceae) is a clonal perennial that is an important component of wetland ecosystems worldwide. Using flow cytometry, we examined the cytotype distributions within five populations of P. australis located in the vicinity of Lake Biwa. As in previous reports, two ploidy levels, octoploid (2n = 8x = 96) and decaploid (2n = 10x = 120), were identified, which are assumed to be the main cytotypes around the lake. The coexistence of two cytotypes was detected in four of the five populations, suggesting the relatively common occurrence of mixed ploidy levels in the populations around Lake Biwa. Although intermingled cytotype distributions were observed in some populations, the 9x cytotype, that is, the expected outcome of inter‐cytotype crosses, was not observed, indicating limited gene flow between the two cytotypes.     

芦苇生态型研究进展

芦苇生态幅极广,适生于多种生境类型。不同的环境选择压力如水深、盐度、养分、气候等交互影响致使芦苇个体及种群间发生不同程度的分化和变异,形成了形态、生理或遗传上互有差异、异地性的不同生态型。尽管基于芦苇表型变异以及遗传变异进行生态型划分的研究已开展很多,但针对芦苇生态型变异规律及其可能的形成机制的认知仍存在较多分歧。在总结近年来有关芦苇生态型研究文献的基础上,通过对影响芦苇生态型变异的主要因素——环境因素和遗传因素的分析,以期为芦苇生态型的划分及其可能的形成机制提供新的研究思路。(1)空间尺度的选择应成为研究者分析、划分芦苇生态型的首要定位。在较大的地理空间尺度上,高度异质性的生境导致某些性状的变异式样具有相对的不连续性,可作为不同芦苇生态型鉴别与描述的主要依据;(2)在合理的尺度定位、取样设计和统计分析的基础上开展的表型变异研究,及进一步基于种群水平的分子标记研究(分子指纹特征或特有等位基因),可为芦苇生态型的鉴定、划分提供更为可靠的参考数据,并且可以甄别生境差异(环境响应)和遗传变异对芦苇不同生态型分化的贡献;(3)应同时进行不同生态型的特定性状与功能(株高、茎粗、生物量、生理抗逆性、水体污染物净化能力等)的定位,推动优良基因型的选育与扩繁。     

有机螯合剂在芦苇富集转运铅中的作用

近年来,随着人口的激增和工农业生产的迅猛发展,土壤和水体的重金属污染日益加重。植物提取技术作为一种新兴的修复重金属污染的治理方法,以其潜在的高效、经济及其生态协调性等优势被广泛关注。其研究主要是利用对某些重金属具有超富集能力的超积累植物或耐性植物,配合添加一定量的鳌合剂来进行修复。由于超富集植物一般生长缓慢且生物量小,因此利用对重金属有一定耐性的生长快速、生物量大的植物来进行修复更具有广阔的应用前景。芦苇作为一种多年生禾本科植物,具有生物量大、耐受性强和分布广泛的特点,已经被研究和应用到环境治理的多个领域。本文通过户外盆栽沙培试验,研究了铅胁迫下,分别在 2-10 mmol·L-1共 5 个浓度梯度的 EDTA 和柠檬酸两种鳌合剂处理下,芦苇生长对铅的响应以及对铅在植物体内的富集转运的影响。初试结果表明∶在 4mmol·L-1 Pb(NO3)2胁迫下,施加 EDTA 对芦苇的生长具有一定的抑制作用。当 EDTA 浓度为 10 mmol·L-1 时,透灌 7 d 后,其芦苇根和地上部(茎和叶)干重分别是空白试验(未加螯合剂)的 68.0% 和 72.3%,而柠檬酸对植物生物量的影响较小。同时,EDTA 和柠檬酸对铅在芦苇体内的富集和转运,都起到了促进作用。分别施加 10 mmol·L-1的 EDTA 和柠檬酸,其植物根部和地上部的铅浓度分别为空白试验的 7.4 倍、10.7 倍、2.5 倍、3.5 倍。EDTA 在促进植物体内铅的吸收和从根部到地上部的转运效率方面要比柠檬酸更为有效。尽管像 EDTA 和柠檬酸这样的鳌合剂能够在一定程度上提高植物的富集效率,但考虑到螯合剂自身对植物的毒害性、对环境的潜在威胁以及运行成本等方面因素,目前,寻找高效、廉价、可生物降解的鳌合剂以及大生物量的耐性植物成为植物提取技术的研究重点。     

Some Aspects of the Importance of Genetic Diversity in Phragmites australis (Cav.) Trin. ex Steudel for the Development of Reed Stands

Various sites of Phragmites australis in Germany (Uckermark and Mark Brandenburg) and sites in Hungary and Denmark were investigated by PCR fingerprinting in order to determine their genetic diversity. Genetic similarities were calculated and, based on this, a cluster analysis was performed. The genetic similarity of reed clones around one lake ranged from between 70 to 100%, that of clones from different lakes was clearly lower. The further apart the clones were situated from each other, the less similar they were. At a wetland site near the shore a sudden colonisation by several new Phragmites clones was observed. This site was located in front of a well established genetically almost homogenous stand within the eulittoral. All the results are discussed in connection with a proposed model of establishment and development of water reed stands: colonization, selection of best adapted clones by competition and the stability of stands.     

Common Reed Phragmites australis: Control and Effects Upon Biodiversity in Freshwater Nontidal Wetlands

Phragmites australis (common reed) has expanded in many wetland habitats. Its ability to exclude other plant species has led to both control and eradication programs. This study examined two control methods—herbicide application or a herbicide‐burning combination—for their efficacy and ability to restore plant biodiversity in non‐tidal wetlands. Two Phragmites‐dominated sites received the herbicide glyphosate. One of these sites was burned following herbicide application. Plant and soil macroinvertebrate abundance and diversity were evaluated pre‐treatment and every year for four years post‐treatment using belt transects. The growth of Phragmites propagules—seeds, rhizomes, and rooted shoots—was examined in the greenhouse and under bare, burned, or vegetated soil conditions. Both control programs greatly reduced Phragmites abundance and increased plant biodiversity. Plant re‐growth was quicker on the herbicide‐burn site, with presumably a more rapid return to wetland function. Re‐growth at both sites depended upon a pre‐existing, diverse soil seed bank. There were no directed changes in soil macroinvertebrate abundance or diversity and they appeared unaffected by changes in the plant community. Phragmites seeds survived only on bare soils, while buried rhizomes survived under all soil conditions. This suggests natural seeding of disturbed soils and inadvertent human planting of rhizomes as likely avenues for Phragmites colonization. Herbicide control, with or without burning, can reduce Phragmites abundance and increase plant biodiversity temporarily. These changes do not necessarily lead to a more diverse animal community. Moreover, unless Phragmites is eradicated and further human disturbance is prohibited, it will likely eventually re‐establish dominance.     

Isoprene emission and primary metabolism in Phragmites australis grown under different phosphorus levels

Aquatic plants are generally used for wastewater purification and phytoremediation, but some of them also emit large amounts of isoprene, the most abundant biogenic volatile organic compound. Since isoprenoid biosynthesis requires high amounts of phosphorylated intermediates, the emission may also be controlled by inorganic phosphorus concentration (Pi) in leaves. We carried out experiments to determine the emission of isoprene from Phragmites australis plants used in reconstructed wetlands to phytoremediate elevated levels of phosphorus contributed by urban wastes. Four groups of plants were grown hydroponically in water containing different levels of KH(2)PO(4). High levels of phosphorus in the water resulted in high Pi in the leaves. High Pi stimulated photosynthesis at intercellular CO(2) concentrations lower and higher than ambient, implying higher ribulose 1,5-bisphosphate carboxylase (Rubisco) activity and higher ribulose 1,5-bisphosphate regeneration rates, respectively. However, isoprene emission was substantially lower at high Pi than at low Pi, and was not associated to photosynthesis rates at high Pi. This surprising result suggests that isoprene is limited by processes other than photosynthetic intermediate availability or by energetic (ATP) requirements under high Pi levels. Irrespective of the mechanism responsible for the observed reduction of isoprene emission, our results show that Phragmites plants may effectively remove phosphorus from water without concurrently increase isoprene emission, at least on a leaf area basis. Thus, Phragmites used in reconstructed wetlands for phytoremediation of urban wastes rich of phosphates will not contribute high loads of hydrocarbons which may influence air quality over urban and peri-urban areas.