Shelley A. James

Ontogenetic differences in mesophyll structure and chlorophyll distribution in Eucalyptus globulus ssp. globulus (Myrtaceae)

Mesophyll structure has been associated with the photosynthetic performance of leaves via the regulation of internal light and CO(2) profiles. Differences in mesophyll structure and chlorophyll distribution within three ontogenetically different leaf types of Eucalyptus globulus ssp. globulus were investigated. Juvenile leaves are blue-grey in color, dorsiventral (adaxial palisade layer only), hypostomatous, and approximately horizontal in orientation. In contrast, adult leaves are dark green in color, isobilateral (adaxial and abaxial palisade), amphistomatous, and nearly vertical in orientation. The transitional leaf type has structural features that appear intermediate between the juvenile and adult leaves. The ratio of mesophyll cell surface area per unit leaf surface area (A(mes)/A) of juvenile leaves was maximum at the base of a single, adaxial palisade layer and declined through the spongy mesophyll. Chlorophyll a + b content showed a coincident pattern, while the chlorophyll a:b ratio declined linearly from the adaxial to abaxial epidermis. In comparison, the mesophyll of adult leaves had a bimodal distribution of A(mes)/A, with maxima occurring beneath both the adaxial and abaxial surfaces within the first layer of multiple palisade layers. The distribution of chlorophyll a + b content had a similar pattern, although the maximum ratio of chlorophyll a:b occurred immediately beneath the adaxial and abaxial epidermis. The matching distributions of A(mes)/A and chlorophyll provide further evidence that mesophyll structure may act to influence photosynthetic performance. These changes in internal leaf structure at different life stages of E. globulus may be an adaptation for increased xeromorphy under increasing light exposure experienced from the seedling to adult tree, similar to the characteristics reported for different species according to sunlight exposure and water availability within their native habitats.

Leaf morphological and anatomical characteristics of heteroblastic Eucalyptus globulus ssp. globulus (Myrtaceae).

Leaf characteristics of Eucalyptus globulus Labill. ssp. globulus vary in response to plant genotype, ontogenetic position and environmental conditions. Glasshouse-grown seedlings from provenances at St Marys, Tasmania, and Wilsons Promontory, Victoria, produced seedling leaves for 10 nodes before producing leaves of juvenile form. Tasmanian provenance seedlings began to produce juvenile leaves after 18 weeks, 4 weeks earlier than Wilsons Promontory seedlings. Tasmanian seedlings continued to produce juvenile foliage, whereas Wilsons Promontory seedlings began producing transitional leaves at 33 weeks. Successive transitional leaves ranged from the juvenile to the adult leaf form owing to variability in the rate of change of particular morphological and anatomical leaf characteristics. Retention of broad, thin, sessile, horizontally oriented, dorsiventral, hypostomatal juvenile leaves of Tasmanian seedlings assists in increasing growth rates under mesic conditions. Early production of thick, narrow, petiolate, vertically oriented, isobilateral, amphistomatal adult leaves by Wilsons Promontory seedlings appears to be related to the stressful conditions within its local habitat. An increase in amphistomy and the distribution of palisade mesophyll on both leaf surfaces with ontogenetic development was strongly related to leaf orientation and light interception, increasing the supply of CO2 for photosynthesis.

Variation among Cupressus species from the western hemisphere based on random amplified polymorphic DNAs

Random amplified polymorphic DNAs (RAPDs) data were analyzed from all the taxa of Cupressus from the western hemisphere. Populations of Cupressus from Arizona and Texas, USA, were found to cluster in the two groups delimited by Wolf (1948): C. arizonica and C. glabra. These data suggest that these taxa might be better recognized at the specific level as per Wolf (1948), rather than at the varietal level (Farjon, 1998) or not at all (Bartel, 1994). A second analysis, which included Chamaecyparis nootkatensis (=Cupressus nootkatensis) and all the taxa of Cupressus from the western hemisphere, revealed four major groups: (1) C. benthamii and C. lindleyi from central Mexico; (2) C. macrocarpa, C. guadalupensis, C. nootkatensis, C. forbesii, and C. bakeri; (3) C. goveniana, C. pigmaea, C. sargentii, C. abramsiana, C. nevadensis, C. arizonica, and C. montana (=C. arizonica var. montana); and (4) C. glabra, C. stephensonii, and C. macnabiana. This analysis supports the placement of Ch. nootkatensis into Cupressus (C. nootkatensis). Trees identified by Wolf (1948) as C. sargentii from Santa Barbara Co., proved to be quite distinct in their RAPDs from C. sargentii populations growing north of this county. Additional field studies are being conducted to resolve the specific status of these plants. Individuals of C. forbesii showed considerable variation within and among populations, suggesting possible hybridization or micro-differentiation.

Identification of roots in lava tube caves using molecular techniques: implications for conservation of cave arthropod faunas

Lava tube cave ecosystems on the volcanic islands of Hawai‘i support communities of rare and highly specialized cave arthropods. In these cave ecosystems, plant roots, both living and dead, provide the main energy source for cave animals. Loss of deep-rooted plants over caves will affect populations of cave-adapted animals living below. Furthermore, the loss of native plant species will likely eliminate host specific cave animals. Thus, identification of plant roots currently found in caves is necessary for the development of effective management actions that encourage the growth of appropriate deep-rooted plant species, thereby protecting the underlying cave ecosystem. We used molecular techniques to identify plant roots found within cave ecosystems on the islands of Maui and Hawai‘i. Sequences of the internal transcribed spacer (ITS) regions and the 5.8S gene of nuclear ribosomal DNA from cave roots were compared to sequences of known plant species either collected on the surface over the footprint of each cave or to sequences accessioned in GenBank. Roots in the cave ecosystem studied on Maui belonged to two alien tree species: Eucalyptus tereticornis and Grevillea robusta. Within the Hawai‘i cave ecosystem, roots of two plant species were identified: the alien tree G. robusta and the native vine Cocculus orbiculatus. The Maui cave ecosystem supports populations of at least 28 species of arthropods, including eight that are blind obligate cave inhabitants. The Hawai‘i cave ecosystem supports 18 arthropod species, of which three are cave-adapted. Creating protected reserves around biologically significant caves, controlling, and preventing the introduction of harmful invasive plant species within the cave footprint, and encouraging the establishment of deep-rooted native plant species is essential for the continued survival of the unique ecosystems found within Hawaiian lava tube cave systems.

Vetiver DNA-Fingerprinted Cultivars: Effects of Environment on Growth, Oil Yields and Composition

Abstract Twenty one accessions of vetiver (Vetiveria zizanioides (L.) Nash, sterile, oil type) and Khus (V. zizanioides, fertile, non-oil type) were analyzed by the use of random amplified polymorphic DNAs (RAPDs). Nineteen of the accessions clustered strongly around the cultigen, Sunshine. Three accessions, Khus, Northern India, Kassel, Germany, and Guang Dong, China clustered loosely and were not closely related to the sterile oil producing vetivers. Thirteen of the vetiver accessions were grown in test plots in Florida, USA, Nepal and Portugal. The largest growth was recorded in Nepal, followed closely by Florida and by the cooler, Mediterranean site in Portugal. No single genotype (DNA cultivar) grew best in every plot. Oil yields (% oil/dry wt.) were highest in Nepal and Portugal. Oil yields ranged from 0.29% to 9.61%. Essential oil production (g/plant) was highest in Nepal and Florida and ranged from 0.02 to 4.17 (g/plant). Analyses of variation among the major compounds is discussed.

Geographic Variation in the Leaf Oils and DNA Fingerprints (RAPDs) of Juniperus thurifera L. from Morocco and Europe

Abstract Samples of Juniperus thurifera L. were collected from the Atlas Mts., Morocco, northern and southern Spain, the Pyrenees, France, Fench Alps and Corse Isaland, France. The leaf oils were analyzed and found to be polymorphic for several major compounds (sabinene, limonene, linalool, piperitone, linalyl acetate and sesquiterpenes). In general, the Moroccan trees were higher in sabinene, γ-terpinene, cis-sabinene hydrate and terpinen-4-ol, but lower in limonene, δ-2-carene, and piperitone than trees from Europe. Analysis based on Random Amplified Polymorphic DNAs (RAPDs) for the aforementioned population plus J. foetidissima (as an outgroup), revealed that the Moroccan J. thurifera populations were most similar to plants from southern Spain, then to populations from France. Although the trees generally clustered by populations, there appear to be some differentiation in the RAPDs between the European J. thurifera populations and the Moroccan populations. Combining previous studies on seeds per cone, proanthrocyanidins, and the current report on the leaf essential oils and RAPDs, there is some support for the continued recognition of J. thurifera var. africana Maire [syn.: J. Africana (Maire); J. thurifera ssp. africana (Maire) Gauquelin, Hassani et Lebreton] in Algeria and Morocco.

Anguilla marmorata (Giant Mottled Eel) Discovered in a New Location: Natural Range Expansion or Recent Human Introduction?

ABSTRACT Freshwater eels in the family Anguillidae spend a majority of their adult life in freshwater but migrate to the ocean to spawn and die. Because freshwater eels are believed to have a long larval period in the open ocean, it is unclear how the present global distribution of species arose. A stock of freshwater eels of the family Anguillidae was found on Palmyra Atoll in the central Pacific Ocean, in June 2003. In October 2003, a single eel specimen was caught using a hand net from this small group of eels on Palmyra Atoll. Morphological and molecular characters (12S and 16S mitochondrial rRNA and cytochrome b mtDNA sequences) were used to identify the species as Anguilla marmorata Quoy & Gaimard. The discovery of these eels on Palmyra supports the hypothesis of natural range expansion from the Indo-Pacific eastward to the Galápagos through the Line Islands, but further analysis of oceanic currents and more variable genes are required to assess whether humans are involved in the recent spread of Anguilla marmorata to these new locations.

Herbarium data: Global biodiversity and societal botanical needs for novel research

Building on centuries of research based on herbarium specimens gathered through time and around the globe, a new era of discovery, synthesis, and prediction using digitized collections data has begun. This paper provides an overview of how aggregated, open access botanical and associated biological, environmental, and ecological data sets, from genes to the ecosystem, can be used to document the impacts of global change on communities, organisms, and society; predict future impacts; and help to drive the remediation of change. Advocacy for botanical collections and their expansion is needed, including ongoing digitization and online publishing. The addition of non‐traditional digitized data fields, user annotation capability, and born‐digital field data collection enables the rapid access of rich, digitally available data sets for research, education, informed decision‐making, and other scholarly and creative activities. Researchers are receiving enormous benefits from data aggregators including the Global Biodiversity Information Facility (GBIF), Integrated Digitized Biocollections (iDigBio), the Atlas of Living Australia (ALA), and the Biodiversity Heritage Library (BHL), but effective collaboration around data infrastructures is needed when working with large and disparate data sets. Tools for data discovery, visualization, analysis, and skills training are increasingly important for inspiring novel research that improves the intrinsic value of physical and digital botanical collections.

Green digitization: Online botanical collections data answering real-world questions

Recent advances in digital technology, coupled with rapidly increasing interest in the creation and dissemination of digitized specimen data for use in broadscale research by botanists and other organismal scientists, have encouraged the development of a variety of new research opportunities in the botanical sciences (e.g., Page et al., 2015; Soltis, 2017). It is now increasingly possible to collect, use, reuse, and share data more easily and effectively. With the advent of the U.S. National Science Foundation’s Advancing Digitization of Biodiversity Collections initiative and the establishment of iDigBio (Integrated Digitized Biocollections; www.idigbio.org) as the national resource for specimen digitization and digital data mobilization, researchers now have access to ever larger and varied digital data sets for visualization, analysis, and modeling and have new opportunities for adopting “big data” strategies for facilitating discovery. The iDigBio portal alone now includes nearly 20 million botanical specimen records, a figure that is growing rapidly as new institutions share their data. In this special issue of Applications in Plant Sciences, which is based on symposium presentations at Botany 2017 (the annual meeting of the Botanical Society of America and affiliated societies) and the XIX International Botanical Congress, authors present a broad array of examples of the latest developments in botanical biodiversity research using digitized specimen data, including in the fields of genomics, conservation assessment, ecology, phenology, and taxonomic revisions. The papers present current trends in the proactive digitization of specimen data that occurs during the collecting and vouchering of specimens and field data; the tools, skills, and strategies needed for linking and visualizing botanical data; and innovative methods for digital discovery. This collection also highlights how digital data are being used in research that expands our understanding and conservation of plant diversity and the environment. Although the source data for the papers in this collection are herbarium specimens, the topics extend well beyond systematics. Broadly integrative plant biologists will be interested in new approaches to using and reusing specimen data—whether locality information for modeling or images for analysis of morphology and/or functional traits. More importantly, digitized herbarium data become even more valuable when linked to other data sources, such as environmental or genetic data. In fact, emerging cyberinfrastructure and new data sources provide unparalleled opportunities for mobilizing and integrating massive amounts of information from organismal biology, ecology, genetics, climatology, and other disciplines. Particularly powerful is the integration of phylogenies with specimen data, enabling analyses of phylogenetic diversity in a spatiotemporal context, the evolution of niche space, and more. Such datadriven synthetic analyses may generate unexpected patterns, yielding new hypotheses for further study. However, a major challenge is the heterogeneous nature of complex data, and new methods are needed to link these divergent data types. Ongoing efforts to link and analyze diverse data are yielding new perspectives on a range of ecological problems. Integration of plant phylogeny, distributions, traits, and ultimately genetics is permitting new

Saving rainforests in the South Pacific: challenges in ex situ conservation

Rainforests in the South Pacific hold a considerable amount of plant diversity, with rates of species endemism >80% in some countries. This diversity is rapidly disappearing under pressure from logging, clearing for agriculture or mining, introduced pests and diseases and other anthropogenic sources. Ex situ conservation techniques offer a means to limit the loss of plant diversity. Seed banking is considered the most efficient and cost effective of these techniques but is applicable only to seed capable of tolerating desiccation and cold storage. Data on the degree of tolerance of these conditions was lacking for more than half of the 1503 South Pacific rainforest genera examined for this review. Of the 710 genera for which data were available, the storage behaviour of 324 was based on an assessment of only one or two species, although 76% of those genera contained at least 10 species. Many of the unstudied or poorly studied genera are shared across several South Pacific nations, providing an excellent opportunity for collaboration on future ex situ research and conservation. Of the 386 genera for which three or more species have been studied, 343 have a very high proportion of species (>95% of those tested) that are suitable for seed banking. Seed banking could therefore provide a suitable means for preserving a large proportion of the rainforest flora before it becomes extinct in the wild. Alternatives for preserving species that are not suitable for seed banking are also discussed.