Patterns of genotypic diversity suggest a long history of clonality and population isolation in the Australian arid zone shrub Acacia carneorum

The genus Caladenia comprises species that exhibit remarkable consistency in terms of growth form and phenological patterns. All taxa are herbaceous perennials, with the shoot arising annually from a single, usually spheroid, tuber and producing a single, hairy leaf. The tuber is annually replaced either side-by-side with the parent tuber or terminating a descending structure known as a dropper. The dropper is a depth-seeking mechanism that enables placement of the tuber at depth in the soil as a means to avoid predation by surface-foraging native mammals or away from the high temperatures and desiccating conditions during summer dormancy. The 3--5 attenuated roots produced at the junction between the tuber and shoot and produced late in the growing cycle and devoid of mycorrhiza suggest their functional significance may relate to water uptake. Mycorrhizal endophytes are confined to a hypertrophic stem region at the soil surface (collar) subtending the leaf that positions the collar directly in the organically rich zone at the soil surface. This morphology is a unique characteristic of several Australasian orchids in the tribe Diuridae. Mycorrhizal infection occurs rapidly, with maximum colonisation in concert with the onset of breaking rains. Pelotons are restricted to cortical cells, with fully developed pelotons throughout infected tissues within a week or so of soil wetting. Infection occurs as a ‘once-off’ event, with little evidence of secondary infection later in the growth cycle and no evidence of peloton digestion. Some taxa utilise vegetative propagation, often leading to localised clustering as for taxa in the ‘filamentosa’ complex or, extensive clonal mats as found in Caladenia flava and C. latifolia where daughter tubers are produced at the end of extending horizontal outgrowths. For the majority of taxa, plants remain dry-season (summer) dormant from a few months up to 7 months for arid-zone taxa, with shoot emergence from the tuber of temperate species thought to occur in response to a drop in the mean minimum temperature. Pollination biology of Caladenia is apparently through a process of deception, either as food or sexual mimics, with some taxa engaging in self-pollination. Here we review the natural history of Caladenia and acknowledge that much of our understanding is based on assumptions of the biology of terrestrial orchids in general and emphasise areas of research and biological enquiry that will be critical in the development of an effective conservation program for the genus.

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Genomic phylogeography of the White-crowned Manakin Pseudopipra pipra (Aves: Pipridae) illuminates a continental-scale radiation out of the Andes

10.1101/713081 ◽

2019 ◽

Cited By ~ 1

Author(s):

Jacob S. Berv ◽

Leonardo Campagna ◽

Teresa J. Feo ◽

Ivandy Castro-Astor ◽

Camila C. Ribas ◽

...

Keyword(s):

Gene Flow ◽

Distinct Species ◽

Passerine Bird ◽

Biological Species ◽

Genetic Connectivity ◽

Population Isolation ◽

Continental Scale ◽

The Andes ◽

Areas Of Endemism ◽

History Of

AbstractThe complex landscape history of the Neotropics has generated opportunities for population isolation and subsequent diversification that place this region among the most species-rich in the world. Detailed phylogeographic studies are required to uncover the biogeographic histories of Neotropical taxa, to identify evolutionary correlates of diversity, and to reveal patterns of genetic connectivity, disjunction, and potential differentiation among lineages from different areas of endemism. The White-crowned Manakin (Pseudopipra pipra) is a small suboscine passerine bird that is broadly distributed through the subtropical rainforests of Central America, the lower montane cloud forests of the Andes from Colombia to central Peru, the lowlands of Amazonia and the Guianas, and the Atlantic forest of southeast Brazil. Pseudopipra is currently recognized as a single, polytypic biological species. We studied the effect of the Neotropical landscape on genetic and phenotypic differentiation within this species using genomic data derived from double digest restriction site associated DNA sequencing (ddRAD), and mitochondrial DNA. Most of the genetic breakpoints we identify among populations coincide with physical barriers to gene flow previously associated with avian areas of endemism. The phylogenetic relationships among these populations imply a novel pattern of Andean origination for this group, with subsequent diversification into the Amazonian lowlands. Our analysis of genomic admixture and gene flow establishes a complex history of introgression between some western Amazonian populations. These reticulate processes confound our application of standard concatenated and coalescent phylogenetic methods and raise the question of whether a lineage in the western Napo area of endemism should be considered a hybrid species. Lastly, analysis of variation in vocal and plumage phenotypes in the context of our phylogeny supports the hypothesis that Pseudopipra is a species-complex composed of at least 8, and perhaps up to 17 distinct species which have arisen in the last ∼2.5 Ma.

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Seeing Red: Some Aspects of the Geological and Climatic History of the Australian Arid Zone

On the Ecology of Australia’s Arid Zone ◽

10.1007/978-3-319-93943-8_2 ◽

2018 ◽

pp. 5-43 ◽

Cited By ~ 2

Author(s):

Brad J. Pillans

Keyword(s):

Arid Zone ◽

History Of ◽

Climatic History

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Isolation and Lack of Potential Mates may Threaten an Endangered Arid-Zone Acacia

Journal of Heredity ◽

10.1093/jhered/esz043 ◽

2019 ◽

Vol 110 (6) ◽

pp. 738-745

Author(s):

Cairo N Forrest ◽

David G Roberts ◽

Andrew J Denham ◽

David J Ayre

Keyword(s):

Reproductive Success ◽

Seed Set ◽

Arid Zone ◽

Genotypic Diversity ◽

Geographic Range ◽

Landscape Scale ◽

Reproductive Assurance ◽

Threatened Plants ◽

Self Fertilization ◽

Adult Plants

Abstract Clonality may provide reproductive assurance for many threatened plants while limiting sexual reproductive success either through energetic tradeoffs or because clones are self-incompatible. Most stands of the Australian arid-zone plant Acacia carneorum, flower annually but low seed set and an absence of sexual recruitment now suggest that this species and other, important arid-zone ecosystem engineers may have low genotypic diversity. Indeed, our recent landscape-scale genetic study revealed that stands are typically monoclonal, with genets usually separated by kilometers. An inability to set sexually produced seed or a lack of genetically diverse mates may explain almost system-wide reproductive failure. Here, using microsatellite markers, we genotyped 100 seeds from a rare fruiting stand (Middle-Camp), together with all adult plants within it and its 4 neighboring stands (up to 5 km distant). As expected, all stands surveyed were monoclonal. However, the Middle-Camp seeds were generated sexually. Comparing seed genotypes with the single Middle-Camp genotype and those of genets from neighboring and other regional stands (n = 26), revealed that 73 seeds were sired by the Middle-Camp genet. Within these Middle-Camp seeds we detected 19 genotypes in proportions consistent with self-fertilization of that genet. For the remaining 27 seeds, comprising 8 different genotypes, paternity was assigned to the nearest neighboring stands Mallee and Mallee-West, approximately 1 km distant. Ironically, given this species’ vast geographic range, a small number of stands with reproductively compatible near neighbors may provide the only sources of novel genotypes.

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Molecular systematics of Australian Calotis (Asteraceae: Astereae)

Australian Systematic Botany ◽

10.1071/sb05001 ◽

2006 ◽

Vol 19 (2) ◽

pp. 155 ◽

Cited By ~ 7

Author(s):

K. Watanabe ◽

K. Kosuge ◽

R. Shimamura ◽

N. Konishi ◽

K. Taniguchi

Keyword(s):

Evolutionary History ◽

Life Form ◽

Arid Zone ◽

Its Region ◽

Base Number ◽

Multiple Origins ◽

Matk Gene ◽

History Of ◽

Ancestral States ◽

Generic Relationships

The intra-generic relationships of the Australian genus Calotis, with various chromosome base numbers from x = 8 to x = 4, were examined by the comparison of nucleotide sequences of the complete ITS region of nuclear rDNA and of the matK gene of chloroplast DNA. Within a monophyletic Calotis, four lineages were identified. Reconstruction of ancestral states suggests that the chromosome base number for Calotis is x = 8. Dysploidal reductions in chromosome base number from x = 8 to x = 7 and from x = 8 to x = 5 or 4 have occurred independently at least three times. Lower base numbers of x = 7, 5, and 4 are found predominantly in the arid and semi-arid zone species of Central and Western Australia. Total karyotypic length (genome size) is greater in perennials than in annuals within the genus Calotis. The elaborated pappus and surface structures of cypsela, and life form of species seem to be homoplasous with multiple origins in the evolutionary history of the lineage.

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Environmental and Climatic Change as Recorded in Geological Sediments from the Arid to Semi-Arid Zone of China

Radiocarbon ◽

10.1017/s0033822200041278 ◽

2001 ◽

Vol 43 (2B) ◽

pp. 619-627 ◽

Cited By ~ 7

Author(s):

Weijian Zhou ◽

Wu Zhengkun ◽

A J T Jull ◽

G Burr ◽

D D Donahue ◽

...

Keyword(s):

Arid Zone ◽

Anthropogenic Impacts ◽

Northern China ◽

Future Research ◽

Southward Shift ◽

History Of ◽

Development And Environment ◽

The Last Glacial Maximum ◽

Semi Arid ◽

The Last Glacial

Stratigraphic investigations together with climatic proxy data measurements and reliable radiocarbon dating show a history of fluctuations of dry and wet environmental conditions in the arid to semi-arid zone of northern China since the late Pleistocene. Based on these data, we are able to reconstruct shifts of the desert margin in two period extremes, the last glacial maximum (21–15 ka) and the Holocene Optimum (9–5 ka). We have compared the present desert margin with that for the two extremes. The results indicate that a southward shift of the present margin of about 3 degrees in latitude might be caused by anthropogenic impact. Hence the influence of human activity must be taken into consideration for sustainable development and environment protection. Future research will be to find a two-way feedback existing between climate and anthropogenic impacts.

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Changes to land tenure and pastoral lease ownership in Western Australia’s central rangelands: implications for co-operative, landscape-scale management

The Rangeland Journal ◽

10.1071/rj11088 ◽

2013 ◽

Vol 35 (1) ◽

pp. 37 ◽

Cited By ~ 12

Author(s):

Eddie J. B. van Etten

Keyword(s):

Western Australia ◽

Land Tenure ◽

Arid Zone ◽

Conservation Status ◽

Livestock Grazing ◽

Government Agencies ◽

Mining Companies ◽

History Of ◽

Pastoral Lease ◽

Management And Conservation

The majority of arid and semiarid land in the Western Australian pastoral zone has a long history of livestock grazing within an extensive network of predominantly family-held pastoral leases. A variety of different groups have purchased pastoral leases in the last five decades and, for many, making a profit from pastoralism is no longer a priority. For the central rangelands of Western Australia, these groups have included: government agencies, who have purchased some 9% of pastoral leases by area; private conservation organisations (<1% purchased); aboriginal communities and groups (~7%); and mining companies (~13%). The purchases of pastoral leases by government agencies was designed to improve the conservation status of arid-zone ecosystems, and is the first step in a process of changing land tenure to a conservation reserve. This paper summarises the extent and other characteristics of these changes in land tenure and ownership of pastoral leases, and explores the implications for land management and conservation, stemming from these changes. It demonstrates that large areas of contiguous land with no or reduced domestic stocking can now be found in many parts of these rangelands, particularly in the Coolgardie, Yalgoo and Pilbara bio-regions, with some leaseholders actively managing land for the conservation of biodiversity and restoring sites degraded through past over-grazing. In some bio-regions, such land covers considerable proportions of sub-catchments, suggesting that broad-scale conservation management and restoration objectives may be realised. It is argued that to fully realise these objectives requires effective communication and co-ordination between land managers, including sharing of ideas, view-points and resources. In particular, mining companies, now major holders of pastoral leases in Western Australia, can play an important role in contributing to and even facilitating such objectives.

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From the desert it came: evolution of the Australian paper daisy genus Leucochrysum (Asteraceae, Gnaphalieae)

Australian Systematic Botany ◽

10.1071/sb16012 ◽

2016 ◽

Vol 29 (3) ◽

pp. 176 ◽

Cited By ~ 6

Author(s):

Alexander N. Schmidt-Lebuhn ◽

Kiarrah J. Smith

Keyword(s):

Arid Zone ◽

Nuclear Gene ◽

Amplicon Sequencing ◽

Success Rates ◽

Ancestral Area ◽

Biogeographic History ◽

Molecular Phylogenetic ◽

Ancestral Area Reconstruction ◽

History Of ◽

Australian Flora

Present patterns of diversity in the Australian flora have been shaped by increasing seasonality since the Eocene, and by pronounced aridification in the past 3 million years. Arid-zone plants are commonly hypothesised to be the products of radiations of ancestrally temperate or coastal lineages, as in the case of the everlasting paper daisy tribe Gnaphalieae (Asteraceae). However, these inferences are often based on higher-level phylogenies, whereas evolutionary processes in the Australian Gnaphalieae have rarely been studied at the species level. Here, we reconstructed the phylogeny and biogeographic history of the small, but ecologically diverse, paper daisy genus Leucochrysum, to examine recent habitat shifts and character changes, at the same time exploring the feasibility of using amplicon sequencing of low-copy nuclear gene regions to resolve phylogenetic relationships in Australian Gnaphalieae. On the balance of evidence, outgroup comparison and ancestral-area reconstruction support an ancestral range in the arid zone with subsequent diversification towards the south-east, demonstrating a complex evolutionary history with a re-colonisation of temperate areas. Low amplification success rates suggest that methods other than amplicon sequencing of currently available primers will be more promising for molecular phylogenetic work at a larger scale.

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Migration without interbreeding: evolutionary history of a highly selfing Mediterranean grass inferred from whole genomes

10.1101/2020.09.03.280842 ◽

2020 ◽

Author(s):

Christoph Stritt ◽

Elena L. Gimmi ◽

Michele Wyler ◽

Abdelmonaim H. Bakali ◽

Aleksandra Skalska ◽

...

Keyword(s):

Evolutionary History ◽

Brachypodium Distachyon ◽

Genotypic Diversity ◽

Plant Evolution ◽

Whole Genome ◽

Continental Scale ◽

Whole Genomes ◽

History Of ◽

Adaptive Phenotypic Plasticity ◽

Independent Expansion

AbstractWhole genome sequences and coalescence theory allow the study of plant evolution in unprecedented detail. In this study we extend the genomic resources for the wild Mediterranean grass Brachypodium distachyon to investigate the scale of population structure and its underlying history at whole-genome resolution. The analysis of 196 accessions, spanning the Mediterranean from Iberia to Iraq, shows that the interplay of high selfing and seed dispersal rates has shaped genetic structure. At the continental scale, evolution in B. distachyon is characterized by the independent expansion of three lineages during the Upper Pleistocene. Today, these lineages may occur in sympatry yet do not interbreed. At the local scale, dispersal and selfing interact to maintain high genotypic diversity. Our study lays a foundation for the study of microevolution in B. distachyon and identifies adaptive phenotypic plasticity and frequency-dependent selection as key themes to be addressed with this model system.

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Historia natural de la anidación de ammophila aberti haldeman (hymenoptera: sphecidae) en Baja California Sur. México

ACTA ZOOLÓGICA MEXICANA (N S ) ◽

10.21829/azm.2008.242719 ◽

2008 ◽

Vol 24 (2) ◽

Cited By ~ 1

Author(s):

María Luisa Jiménez-Jiménez ◽

Carlos Palacios-Cardiel

Keyword(s):

North America ◽

Natural History ◽

Baja California ◽

Arid Zone ◽

First Record ◽

Baja California Sur ◽

History Of ◽

Historia Natural

Natural history of nesting of the wasp Ammophila aberti Haldeman during autumn 2006-2007 in Baja California Sur, Mexico is described. While this wasp has been found in Mexico, this is the first record of thisbehavior in the subtropical, arid zone of North America. A comparison with nesting observations in other places was made. Two species of ants are predators of these wasp larvae.

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