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Results for “Herbarium specimens”

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8 recordsLinked to original sources
PubMed2026

The impact of non-native trees on galling and herbivory in New York City across space and time.

Cities and suburbs frequently plant native and non-native trees as foundation species, with non-natives cultivated in these areas for centuries while remaining non-invasive. Although previous research has found that native trees often host more arthropods, studies have not simultaneously looked across space and time to determine the consistency of tree origin on urban arthropods. We combined varied methods across spatial and temporal scales in New York City to test if native tree leaves consistently have more insect and mite interactions than long-established non-native trees, predicting stronger effect sizes for specialists (galling arthropods) than generalists (herbivory). We examined (1) congeneric species pairs, controlled for growing conditions and stoichiometry in an arboretum, (2) diverse oaks at a botanical garden, (3) community science records across Brooklyn, and (4) herbarium specimens from 1883 through present across the city. Across spatiotemporal scales, we found consistent results. Specialist interactions were striking: contemporary native trees supported numerous galling species, while only one congeneric non-native species hosted any galls. For generalists, contemporary native trees had equivalent to slightly greater herbivory. Over the last century, herbarium records showed that herbivory increased on non-native trees to nearly the level of natives, whereas native trees increased in gall abundance while non-native trees remained rarely galled. Our results demonstrate the impact of tree origin on tree-arthropod interactions in a real-world urban setting, with far fewer galls even when non-native tree species have been cultivated locally for centuries. Our findings will help city planners and property owners confidently choose native trees to promote arthropod biodiversity.

Trees↗
PubMed1979

Hyperaccumulation of nickel by Alyssum Linnaeus (Cruciferae).

Herbarium specimens of all except one of the 168 recognized species of Alyssum Linnaeus have been analysed for their nickel content in order to identify hyperaccumulators (greater than 1000 microgram per g dry mass) of nickel. A further 31 hyperaccumulators (all in section Odontarrhena) were discovered in addition to the 14 European species reported earlier. Pot trials on the non-accumulator A. serpyllifolium Desfontaines and the hyperaccumulator A. pintodasilvae Dudley in ed. involving addition of nickel to the medium in which the plants were growing, showed that not all species of of section Odontarrhena were able to act as hyperaccumulators of nickel. Hyperaccumulation occurred almost exclusively in the eastern Mediterranean area and Turkey. There appeared to be a definite correlation between species diversity, proliferation and endemism on the one hand, and extremely high nickel concentrations (greater than 1%) on the other. The data have been used to assess the evidence for promoting section Odontarrhena to generic rank.

Biological Transport↗
PubMed2026

Centuries of Potato Late Blight: Tracking Global Epidemics and Managing Future Outbreaks.

Phytophthora infestans killed the potato crop in Ireland in 1845, leading to widespread famine and the death of more than one million people. Historic herbarium specimens from the famine era were used to understand the pathogen's biology and track its global spread, providing a valuable resource for research. Historic outbreaks in the United States and Europe were caused by the FAM-1 lineage, whereas the US-1 lineage spread later. The famine lineage was basal in the phylogeny and ancestral to modern US-1, Mexican, and globally aggressive lineages. An admixture between the famine lineage and the Andean species Phytophthora andina was revealed, indicating a South American origin of the disease. Temporal changes in the presence and abundance of virulence genes were observed in historic compared to modern genomes. Expansion in effector abundance occurred as new genotypes emerged in the mid-twentieth century. Disease surveillance and genotyping on a global scale have helped to inform disease management.

Solanum tuberosum↗
PubMed2026

Evolutionary dynamics of the chloroplast genome in Abutilon (Malvoideae, Malvaceae).

The genus Abutilon Mill. (Malvaceae) comprises approximately 178 species distributed across tropical and subtropical regions, many of which hold significant ornamental, economic, and medicinal value; yet its taxonomic classification remains challenging. In this study, six species were sequenced from herbarium specimens, and the chloroplast (cp.) genomes of ten additional species were assembled de novo from publicly available raw data. Three previously reported cp. genomes were also incorporated to characterise cp. genome structure, identify polymorphic loci, and perform phylogenetic analyses. The cp. genomes ranged from 159,458 to 160,454 bp and exhibited the typical quadripartite structure, with each genome containing 112 unique genes (78 protein-coding, 30 tRNA, and 4 rRNA) that showed conserved content and organisation. These genomes exhibited high similarity in GC content, inverted repeat boundaries, relative synonymous codon usage, amino acid frequencies, and substitution patterns. However, notable variation was observed in the total number of simple sequence repeats, ranging from 70 to 97 per genome. Selection analyses indicated predominant purifying selection, with evidence of episodic positive selection detected in rpoC2, rbcL, and ycf1. Two codons in rbcL were clade-specific and provided phylogenetic signal distinguishing Australian and Old World pantropical species. Nucleotide diversity analysis identified six highly polymorphic intergenic spacers (trnH-psbA, rps19-rpl2, psbT-pbf1, psaC-ndhD, trnR-atpA, and ndhJ-ndhK) that may be suitable for taxonomic studies. The phylogeny from maximum likelihood (ML) and Bayesian inference (BI) resolved two major clades: one comprising an exclusively Australian lineage occurring predominantly in arid and semi-arid environments, and the other a pantropical lineage spanning multiple continents. Abutilon grandifolium was recovered as sister to the remaining sampled Abutilon taxa in both ML and BI analyses, although no biogeographic origin inference can be drawn from this placement pending broader taxon sampling and integration of nuclear genomic data. These findings provide insights into the evolutionary dynamics of the cp. genome in Abutilon and offer a foundational genomic framework for refining Abutilon taxonomy.

Genome, Chloroplast↗
PubMed1978

Embedding softened herbarium material in Spurr's resin for histological studies.

Plant organs, including stems, rhizomes, leaves, roots, petals, sporangia and flower pedicels obtained from dried herbarium specimens of a variety of plant species have been softened with Aerosol OT and subsequently dehydrated in a graded series of acetones and embedded in Spurr's resin. Although the quality of preservation varied, sections of a variety of materials showed excellent cellular preservation. Sections stained through the resin with toluidine blue O and examined with either bright field microscopy or with crossed polarizers showed good cell detail. Histochemical tests for callose, polysaccharides, and cellulosic walls, using sections from which the resin had been removed by sodium methoxide and then viewed with an epifluorescence microscope, gave excellent results.

Cell Wall↗
PubMed1979

Improved imprinting technique for study of plant tissues.

The exposed surface of plant tissues is coated with nail varnish. When peeled off, the transparent coating film bears a replica imprint of the tissue. Transparent adhesive tape is used for lifting the film imprint and mounting it on a microslide without curling. By a similar method, an opaque sealant replica with an aluminum foil support may be prepared which can serve as a mold for obtaining a transparent secondary imprint useful for light microscopic studies. The replicas can be stored like herbarium specimens for future use.

Cellulose↗
PubMed1979

Nickel uptake by Flacourtiaceae of New Caledonia.

Herbarium and field specimens (over 300) of all of the Flacourtiaceae of New Caledonia were analysed for nickel in order to identify hyperaccumulators (greater than 1000 microgram/g dry mass) and to assess nickel accumulation in relation to the evolutionary status of 'nickel plants' of New Caledonia. One hyperaccumulator was identified in the genus Lasiochlamys, ten among Xylosoma, one among Casearia and seven among Homalium. Although these Homalium nickel plants had previously been recorded, fresh data for these and other Homalium are presented. The remarkable tolerance of Flacourticeae to ultrabasic rocks is shown by the fact that 75% of the species are found on such substrates. The number of hyperaccumulators was greatest in the genera Xylosoma and Homalium. The Flacourtiaceae are among the most primitive of all angiosperms and in common with other primitive hyperaccumulators, contain nickel as a complex with citric acid. The only advanced New Caledonian nickel plant (Psychotria douarrei) has most of its nickel bound with ligands other than citric acid, a feature of other advanced hyperaccumulators. It is postulated that nickel complexing with citric acid may be a primitive character. Most of the New Caledonian nickel plants belong to the order Violales of subclass Dilleniidae. It is suggested that hyperaccumulation of nickel is an evolutionary character which occurs in long-indisturbed floras such as that of New Caledonia.

Biological Transport↗
PubMed2026

Short-read genome skimming enables molecular barcoding of old myxomycete collections.

This study evaluates the effectiveness of Illumina-based genome skimming for barcoding myxomycete herbarium collections ranging from 29 to 91 years in age. We successfully retrieved partial sequences of the standard marker gene (nucSSU) in all cases, as well as additional markers (mtSSU, EF1a, and COI) for certain collections. Altogether, 28 genes were recognized in the studied material. In a 33-year-old specimen of Lindbladia tubulina, the assembly reached an N50 of 4.19 kb, enabling the recovery of extended functional loci. The input genomic DNA quantity emerges as the primary determinant of sequencing success. Samples with high DNA yields provide representative amounts of contigs coming confirmedly (matching sequences in the NCBI nucleotide database) or potentially (no-hit fraction) from myxomycetes, regardless of specimen age. In addition to target DNA, we revealed distinct signals of both anthropogenic contamination (human DNA and skin microflora) and natural substrate inhabitants, including oribatid mites and bacteria from dead wood, soil, and grass litter. Thus, even in old collections, metagenomic data still carry information regarding the substrate upon which the myxomycete developed. The results demonstrate that short-read genome skimming may help to integrate historical type material of myxomycetes into contemporary phylogenetic research. This method overcomes the length-dependent limitations of traditional Sanger sequencing, thus providing a roadmap for the future of museomics in myxomycetology.

Amoebozoa↗