A molecular phylogeny of the subfamily Arundinoideae (Poaceae)

Includes bibliography.The subfamily Arundinoideae has long been considered to be an unnatural assemblage of genera, the relationships of which are obscure or unknown. Because morphological and anatomical data have, to date, been unable to elucidate relationships among these genera, sequence data from two chloroplast genes are used to elucidate relationships among 33 arundinoid genera. Sequence data from the variable, grass-specific insert in the rpoC2 gene is used to determine the relationships among 73 grass species from all currently recognised subfamilies. Phylogenetic analysis of this sequence data required the development of specialised alignment techniques based on testing assumptions of positional homology. Results of the analyses based on these alignments suggest that the Arundinoideae is divisible into four lineages, corresponding approximately to the tribes Danthonieae, Arundineae, Aristideae and Thysanolaeneae. Several arundinoid representatives are placed in other subfamilies. The rpoC2 sequence data was too variable to elucidate relationships at the tribal and subfamilial level. For this purpose, sequence data of the highly conserved rbcL gene was obtained from 22 taxa selected from the lineages identified by the rpoC2 study. Phylogenetic analysis of a total of 36 sequences resolved some of the relationships of the major clades, but other relationships were poorly supported. In an attempt to improve the resolution of these major clades, the rpoC2 and rbcL data sets were combined with restriction site data. These three data sets were analysed in a variety of combinations using both data combination and tree consensus methods to assess support of the phylogenetic relationships. Despite this, the resolution of the relationships among the Arundineae, Danthonieae, Aristideae and Chloridoideae was not resolved with any finality, although a (Arundineae (Danthonieae (Aristideae, Chloridoideae))) relationship is proposed as being most likely. The molecular phylogeny implies that eight grass subfamilies should be recognised. Two of these, the Danthonioideae and Aristidoideae, are new and the Arundinoideae is redelimited. Furthermore, new tribes in the subfamilies Centothecoideae (Thysanolaeneae) and Chloridoideae (Centropodieae) are proposed to accommodate lineages and taxa misplaced in the subfamily Arudinoideae as previously delimited

A technique for evaluating species richness maps generated from collections data

There is considerable pressure on conservation planners to use existing data from herbarium and museum collections for planning and monitoring, despite the weaknesses of such data. It is thus important to be able to assess the quality of this information. One application of these data is the production of species richness maps. However, sampling effort is generally not consistent throughout a region for maps generated from collections data, and it is thus desirable to identify geographic grid cells (such as quarter degree squares: QDS) for which there has been low sampling effort. We describe a technique that can be used to identify QDS that are likely to have low species richness that is due to insufficient sampling effort rather than to low actual species richness. The technique exploits relationships between climate and species richness to detect QDS that are poorly sampled. This approach offers advantages over the current practice of applying a single threshold across the entire map region to detectQDSthat are poorly sampled. Here we report on the application of our technique to plant species richness data in the PRECIS database. Results reveal that the majority of QDS in the Flora of Southern Africa region can be considered to be poorly sampled, even when using conservative thresholds for richness values. The advantages and weaknesses of the technique are discussed and issues requiring further investigation are highlighted

Study Time Within Pre-Registration Nurse Education: A Critical Review Of The Literature

Background Pre-registration nursing students throughout the United Kingdom (UK) are required to complete a minimum number of theory hours within the course. Anecdotal evidence suggests that students are required to attend campus for approximately fifty percent of the theory hours. The remaining theory hours are often labelled as 'study time' in which students are not required to attend campus. There is a general assumption amongst many academics that all students are prepared and motivated to direct their learning and therefore use this time to study. However some students chose to work during this time and many have dependents. Considering the increasing cost of nurse education combined with the government cuts to student bursaries in England it is timely to review the literature to determine how study time is used within pre-registration nurse education. Objective To present a critical review of the literature pertaining to study time in pre-registration nurse education. Design An integrative review of the literature. Data Sources A search of electronic databases: Cumulative Index to Nursing and Allied Health (CINAHL); Cochrane; Medline; Science Direct; Blackwell Synergy; Electronic Journals Service (EJS); Scopus; Taylor & Francis, Eric and Routledge Wiley was undertaken. Review Methods The inclusion criteria consisted of peer reviewed primary research, discussion papers, unpublished doctoral theses' and editorial papers directly related to the key words and nurse education published in English. Results Twelve papers were included in the review. Analysis of the papers led to the development of two themes: orientation to self-directed learning (SDL) and preparation for SDL. Conclusions The literature demonstrates that pre-registration nursing students lack the necessary skills for SDL. There is a lack of research on how study time is used within pre-registration nurse education. This calls for empirical research to fully explore how nursing students and lecturers perceive study time within pre-registration nursing curricula

Mechanisms generating biological diversity in the genus Platypleura Amyot & Serville, 1843 (Hemiptera: Cicadidae) in southern Africa: implications of a preliminary molecular phylogeny

Truly understanding biological diversity requires a move from descriptive studies to mechanistic interpretations based on comparative biology and a thorough recognition of the natural history of the focal organisms. A useful step in such comparative studies is the generation of a phylogeny, so that one can assess the phylogenetic independence of the focal taxa and trace the evolutionary significance of their characteristics. As a preliminary to such studies on the platypleurine cicada genus Platypleura, we sequenced 498 bases of the cytochrome oxidase I (COI) gene from thirteen African species. To circumvent problems with outgroup selection, we also included sequences from representatives of the platypleurine genera Brevisiana, Capcicada, Munza, Oxypleura, Severiana, and Systophlochius, all of the subtribe Platypleuriti, and two species of the genus Ugada, of the subtribe Hainanosemiiti. The resulting phylogenies support the synonymization of the monotypic genus Systophlochius with the widespread, speciose genus Platypleura; confirm the placement of Platypleura sp. 7 in that genus; and confirm the independence of Capcicada and Platypleura. Although the preliminary phylogeny lacks strong support at many nodes, it suggests that three radiations of Platypleura have occurred in southern Africa and that there was progressive southward speciation of these radiations. A novel modification of the ancestral area analysis further suggests that the group has an ancestral association with acacias but there were five independent speciation events associated with host- switching. These insights can be summarized by a general hypothesis that the mechanisms underlying platypleurine biodiversity in southern Africa involve two ancient vicariance events and subsequent speciation by vicariance, switching of plant associations, and changes of habitat preferences. We offer this example to illustrate how analysis of preliminary data can help to generate hypotheticodeductive research hypotheses, to provoke interest in testing these hypotheses, and to illustrate the utility of phylogenies beyond systematics

A yellowwood by any other name: molecular systematics and the taxonomy of Podocarpus and the Podocarpaceae in southern Africa

We briefly review the taxonomic history of the Podocarpaceae, with an emphasis on the recognition of numerous segregate genera out of Podocarpus sensu lato. Despite some controversy over the recognition of these genera, molecular data (DNA sequences) provide evidence that supports this taxonomy. The implications for African Podocarpaceae are discussed. In particular, molecular data support the recognition of Afrocarpus as distinct from Podocarpus. Additional taxonomic problems concerning the possible segregation of Podocarpus milanjianus from P. latifolius are addressed using DNA sequence data from the nuclear internal transcribed spacer 2 (ITS2) region. Results of this are inconclusive, and suggest that alternative DNA-based evidence, such as from AFLPs or microsatellites, may be more informative in resolving such species complexes in African Podocarpus

Position, position, position : mites occupying leaf domatia are not uniformly distributed in the tree canopy

Leaf domatia are plant-produced cavities usually found in the axils of major veins on the abaxial side of leaves. These structures are found in many woody dicotyledonous plants and mediate a mutualistic relationships between predacious and Fungivorous mites and the host plants they protect. Mites inhabit leaf domatia for shelter and to reproduce and develop. In turn, the plants are hypothesized to benefit from increased defense against pathogens and small arthropod herbivores. Here we assess the distribution of mites throughout the tree canopy to determine if certain regions of the canopy are preferred. Our results suggests that mites prefer leaves found in the lower regions of the tree canopy and avoid leaves at the top, where they may be exposed to harsher climatic conditions. This study is one of the first to document aspects of the plant – mite mutualism from African species.The National Research Foundation (NRF) of South Africa and the Department of Science and technology Centre of Excellence in Tree Health Biotechnology (CTHB). The first author also acknowledges financial support from the Canon Collins Trust and GreenMatter.http://www.elsevier.com/locate/sajb2018-01-31hb2016Plant Scienc

A comparative study of the anatomy of leaf Domatia in Gardenia thunbergia Thunb., Rothmannia capensis Thunb., and Rothmannia globosa (Hochst.) Keay (Rubiaceae)

Many dicotyledonous plants produce structures called leaf domatia. Approximately 28% of 290 families have species with leaf domatia. These structures are abundant within the Rubiaceae and Vitaceae. 26% and 16% out of 206 representative species cited in literature from 48 plant families belong to the Rubiaceae and Vitaceae respectively. Leaf domatia are usually associated with mites and often mediate mutualistic relationships with predacious mites. These structures are pockets found in the underside of the leaf, where the secondary vein axils meet the major vein. In the present study, we examine the anatomical structures of leaf domatia from three plant species (Gardenia thunbergia Thunb., Rothmannia capensis Thunb., Rothmannia globosa (Hochst.) Keay) from the Rubiaceae family in order to find out if their internal tissues differ. These plants were sectioned and viewed under a Light Microscope in order to document their internal anatomy. A Transmission Electron Microscope was used to search for the presence of cuticular folds in their epidermis, which are thought to assist plant to communicate with mites. Results from this study suggested that the main features of domatial anatomy are the presence of an extra layer of tissue in the lower epidermis, a cuticle, cuticular folds, trichomes and the presence of an invagination. Cuticular folds were present inside the domatia but were not restricted to the domatial lamina. Thus, we conclude that these structures do not assist plant in plant-mite communication. This study provides a better understating of the anatomy of leaf domatia of the Rubiaceae.The National Research Foundation (NRF) of South Africa and the Department of Science and Technology Centre of Excellence in Tree Health Biotechnology (CTHB).https://www.mdpi.com/journal/plantsdm2022Plant Production and Soil Scienc