腊叶标本的装订

一株植物或者植物体的一部分经过压制干燥以后称为腊（读音xi）叶标本。腊叶标本经过装订可以收藏在标本柜中长期保存,为生产、科研和教学服务。目前,我国各地中学已经普遍开展自制腊叶标本,为生物学教学眼务。由于各所学校采用的装订方法和用具不同,使得标本装订后质量各异。为了提高腊叶标本的装订质量,在此介绍2种较流行的腊叶标本装订法。1胶粘装订法该方法所需用具较多,装订速度快,是国际上较流行的腊叶标本装订法。1．工装订用具台纸垫衬标本用,标本装订在台纸上。台纸要求坚韧,通常用白卡纸制作,大小为8开,约39ｘ28cm。标…     

肉质植物腊叶标本的压制方法

许多肉质植物具有极强的生命力 ,即使在完全无水或被紧压在标本吸水纸中时 ,仍能生存很长时间。因此 ,用常规的方法压制肉质植物 ,植物体往往会发霉变色、皱缩 ,很难获得完美的效果。下面介绍两种方法 ,能使植物体的颜色和形状基本保持原样。两种方法前期处理过程完全相同 ,都是先取下花进行压制 ,然后整理肉质茎。对有粗大肉质茎的植物体 ,要将茎纵切 ,尽可能除去薄壁细胞。接下来两种方法的处理方式有所不同 ,现分别介绍如下。1　乙醇法将经过整理的植物体置于两个厚 1.5cm的有孔薄夹板 (30 cm× 4 5cm)当中 ,夹板孔直径为 0 .5cm,孔与孔…     

如何使腊叶标本更美观

一份制作良好的腊叶标本,在保证器官完整、鉴定和记录准确的同时,还应尽量保持植物本形姿态的优美,色泽的艳丽,今使用者目及时产生美感,印象深刻。正如我国著名植物学家钱崇澍指出的:一份标本上了台纸,就应该像一幅美丽的图画……下面就笔者多年的经验,通过几个小专题来介绍一些使腊叶标本更美观的具体做法。一、苔藓、卷柏之类的处理方法     

如何制作铁杉类腊叶标本

植物标本是植物分类工作的物质基础。为了正确地鉴定和利用植物,必须要具备有科学研究和利用价值的植物标本。但由于各种植物的生长和生理特性的不同,往往有很多植物难以制作出完整的腊叶标本,铁杉类植物就是一个明显的例子。这类植物采集后,一经干燥叶便纷纷脱落（见图１）,制作出来的标本既不美观,更无科学价值。为了解决这一难题,我经过多年来的反复实践不断探索,终于摸索出一套采集和制作的有效方法。制作出了便于鉴定和分析,以及具有保存价值的铁杉类植物标本。一、铁杉类植物标本的采集多年的实践表明,采集铁杉类植物标本的…     

蕨类植物腊叶标本叶表皮制片技术的改进

对蕨类植物腊叶标本叶表皮的制片技术进行了一些改进,克服了传统叶表皮制片中易出现的不足之处,简化了整个制作过程.这种方法使得蕨类植物叶表皮显微制片技术更加完善,可以为从事植物形态分类学基础研究的工作者提供技术支持.     

用铝制波纹板干燥腊叶标本

目前国内普遍采用的干燥植物腊叶标本的方法,主要有用草纸吸水干燥和瓦楞纸烘烤两种。前者压制而成的标本质量较好,却十分费时费工,后者虽大大提高了效率,但瓦楞纸用不了多久就会变形,而且容易失火,也并不十分理想。现介绍一种较好的干燥腊叶标本的方法。制备长44厘米,宽30厘米的铝制波纹板若干,将采来的新鲜标本夹压在报纸中,用铝板将其上下夹住,     

腊叶标本中微小种子SEM样品制备

腊叶标本中微小种子表面的污染物会影响对其表面特征的观察。经低浓度洗洁精(0．001％)浸泡→超声波振动(33kHz,50W)→系列酒精浓度清洗处理后,在SEM下,处理后的种子表面比处理前更加清晰。此方法操作简便、效果明显,并且安全和无污染。     

介绍一种保持腊叶标本原色的制作方法

在生物学教学中,学生所观察的植物标本应具备植物本身特征及原有的色彩,这样效果会更好。通过探索我们用下列方法制得的标本能保持住植物本身的色泽。     

植物塑封标本的制作

把一株完整的具有根、茎、叶、花等的植物经整理、压平、干燥、保色、塑封后,就可以制成一份完美的植物塑封标本,供教学使用。经过两年的摸索、实践,我们成功地制作了２００ 多份植物塑封标本     

植物病害腊叶标本硬胶套制作法

主要介绍了植物病害标本的采集,腊叶标本保色压制方法,硬胶套制作新法的详细制作过程以及标本使用管理中应注意的问题。     

Accelerating plant DNA barcode reference library construction using herbarium specimens: improved experimental techniques

A well‐covered reference library is crucial for successful identification of species by DNA barcoding. The biggest difficulty in building such a reference library is the lack of materials of organisms. Herbarium collections are potentially an enormous resource of materials. In this study, we demonstrate that it is likely to build such reference libraries using the reconstructed (self‐primed PCR amplified) DNA from the herbarium specimens. We used 179 rosaceous specimens to test the effects of DNA reconstruction, 420 randomly sampled specimens to estimate the usable percentage and another 223 specimens of true cherries (Cerasus, Rosaceae) to test the coverage of usable specimens to the species. The barcode rbcLb (the central four‐sevenths of rbcL gene) and matK was each amplified in two halves and sequenced on Roche GS 454 FLX+. DNA from the herbarium specimens was typically shorter than 300 bp. DNA reconstruction enabled amplification fragments of 400–500 bp without bringing or inducing any sequence errors. About one‐third of specimens in the national herbarium of China (PE) were proven usable after DNA reconstruction. The specimens in PE cover all Chinese true cherry species and 91.5% of vascular species listed in Flora of China. It is very possible to build well‐covered reference libraries for DNA barcoding of vascular species in China. As exemplified in this study, DNA reconstruction and DNA‐labelled next‐generation sequencing can accelerate the construction of local reference libraries. By putting the local reference libraries together, a global library for DNA barcoding becomes closer to reality.     

Ready-to-use DNA extracted with a CTAB method adapted for herbarium specimens and mucilaginous plant tissue

This report summarizes major changes in previously published protocols for DNA extraction to improve the quality of DNA extracted from plants. Here, we highlight the critical modifications in the original protocols. The efficiency of these changes results in high-quality DNA ready to use in a variety of phytogenetically distant plant families, in particular species with mucopolysaccharides. The DNA obtained can be used without further purification in various molecular biology assays, including direct sequencing and AFLP and RAPD (random-amplified polymorphic DNA) analyses. The effectiveness of this method is proven by the amplification and sequencing of PCR products of up to 1 kb with DNA extracted from herbarium tissue ≥60 years old. This versatility is not usually found in DNA extraction protocols. In addition, this method is quick, adaptable to standard laboratories, and most important, safer and more cost-effective.     

A global genetic analysis of herbarium specimens reveals the invasion dynamics of an introduced plant pathogen

The introduction, spread, and impact of fungal plant pathogens is a critical concern in ecological systems. In this study, we were motivated by the rather sudden appearance of Acer macrophyllum heavily infected with powdery mildew. We used morphological and genetic analyses to confirm the pathogen causing the epidemic was Sawadaea bicornis. In subsequent field studies, this pathogen was found in several locations in western North America, and in greenhouse studies, A. macrophyllum was found to be significantly more susceptible to S. bicornis than nine other Acer species tested. A genetic analysis of 178 specimens of powdery mildew from freshly collected and old herbarium specimens from 15 countries revealed seven different haplotypes. The high diversity of haplotypes found in Europe coupled with sequence results from a specimen from 1864 provides evidence that S. bicornis has a European origin. Furthermore, sequence data from a specimen from 1938 in Canada show that the pathogen has been present in North America for at least 82 years revealing a considerable lag time between the introduction and current epidemic. This study used old herbarium specimens to genetically hypothesize the origin, the native host, and the invasion time of a detrimental fungal plant pathogen.     

DNA damage in plant herbarium tissue

Dried plant herbarium specimens are potentially a valuable source of DNA. Efforts to obtain genetic information from this source are often hindered by an inability to obtain amplifiable DNA as herbarium DNA is typically highly degraded. DNA post-mortem damage may not only reduce the number of amplifiable template molecules, but may also lead to the generation of erroneous sequence information. A qualitative and quantitative assessment of DNA post-mortem damage is essential to determine the accuracy of molecular data from herbarium specimens. In this study we present an assessment of DNA damage as miscoding lesions in herbarium specimens using 454-sequencing of amplicons derived from plastid, mitochondrial, and nuclear DNA. In addition, we assess DNA degradation as a result of strand breaks and other types of polymerase non-bypassable damage by quantitative real-time PCR. Comparing four pairs of fresh and herbarium specimens of the same individuals we quantitatively assess post-mortem DNA damage, directly after specimen preparation, as well as after long-term herbarium storage. After specimen preparation we estimate the proportion of gene copy numbers of plastid, mitochondrial, and nuclear DNA to be 2.4-3.8% of fresh control DNA and 1.0-1.3% after long-term herbarium storage, indicating that nearly all DNA damage occurs on specimen preparation. In addition, there is no evidence of preferential degradation of organelle versus nuclear genomes. Increased levels of C→T/G→A transitions were observed in old herbarium plastid DNA, representing 21.8% of observed miscoding lesions. We interpret this type of post-mortem DNA damage-derived modification to have arisen from the hydrolytic deamination of cytosine during long-term herbarium storage. Our results suggest that reliable sequence data can be obtained from herbarium specimens.     

Preservation of secondary fungal metabolites in herbarium lichen specimens

Fresh picked and herbarium thalli of Cladonia stellaris, C. rangiferina, Allocetraria nivalis, A. cucullata, Cetraria islandica, Peltigera canina, and Nephroma articum epigene lichens were studied using the immune-enzyme analysis. No big difference was observed in the contents of mycotoxin secondary metabolites, i.e., deoxynivalenol, diacetoxyscirpenol, zearalenone, alternariol, citrinin, sterigmatocystin, cyclopiazonic acid, mycophenolic acid, emodin, and PR-toxin. The discovery of these substances in the specimens preserved for several decades shows that lichens have an effective system of conservation of metabolic exchange products.     

Explaining invasiveness from the extent of native range: new insights from plant atlases and herbarium specimens

Aim

We tested the relationship between the extent of the native range and the success (number of occurrences) in the introduced range of European vascular plant species naturalized in the province of Québec (Canada). We hypothesized that the performance of models linking native range size and species invasiveness can be improved if residence time and climate tolerance are taken into account.

Methods

The extent of the native range (Europe, Asia) was estimated using plant atlases. The number of occurrences in the introduced range (Québec) was estimated using the number of herbarium specimens stored in herbaria. Herbarium specimens were also used to obtain residence time. Plant hardiness was used as an indicator of the suitability of a species to the climate of the introduced range. Multiple linear regression models, corrected to take into account phylogenetic biases, were used to calculate correlations between the extent of the native range and the number of occurrences in the introduced range.

Results

The larger the native distribution area in Eurasia, the greater the number of occurrences (herbarium specimens) in Québec. The shorter the residence time and the less hardy the plant, the fewer the number of occurrences. In all models tested, the phylogenetic structure explained a significant proportion of the variance, but its influence decreased as the number of species or area studied (Europe versus Eurasia) increased.

Main conclusions

The extent of the native range is a good explanatory variable for the invasion success of vascular plants, especially once other factors (residence time, climate tolerance, phylogeny) are taken into account. Thus, a model using these variables could be used by environmental managers to flag species warranting further investigation. With the emergence of online databases, gathering the required information is becoming easier and cheaper. As online databases continue to improve and new analytical tools are developed, this approach will become even more powerful.

     

Application of glycol methacrylate embedding to herbarium specimens of fruits

Aldehyde fixation and glycol methacrylate embedding were applied to herbarium specimens of fruits of the Compositae. Sections 1-2 micron thick were cut with glass knives. Softening was unnecessary and the hydrophilic properties of the resin permitted staining with a number of dyes. Specimens were examined with bright field and polarized light microscopy. The technique gives good structural preservation and resolution even with 81-year-old herbarium material.     

Continental-scale patterns of Cecropia reproductive phenology: evidence from herbarium specimens

Plant phenology is concerned with the timing of recurring biological events. Though phenology has traditionally been studied using intensive surveys of a local flora, results from such surveys are difficult to generalize to broader spatial scales. In this study, contrastingly, we assembled a continental-scale dataset of herbarium specimens for the emblematic genus of Neotropical pioneer trees, Cecropia, and applied Fourier spectral and cospectral analyses to investigate the reproductive phenology of 35 species. We detected significant annual, sub-annual and continuous patterns, and discuss the variation in patterns within and among climatic regions. Although previous studies have suggested that pioneer species generally produce flowers continually throughout the year, we found that at least one third of Cecropia species are characterized by clear annual flowering behaviour. We further investigated the relationships between phenology and climate seasonality, showing strong associations between phenology and seasonal variations in precipitation and temperature. We also verified our results against field survey data gathered from the literature. Our findings indicate that herbarium material is a reliable resource for use in the investigation of large-scale patterns in plant phenology, offering a promising complement to local intensive field studies.