Genetic Variation and Phenotypic Plasticity in Populations of Paterson's Curse (Echium plantagineum L.) In South-Eastern Australia

1985 ◽  
Vol 33 (6) ◽  
pp. 677 ◽  
Author(s):  
H Wood ◽  
R Degabriele
Keyword(s):  
Genetic Variation ◽  
Phenotypic Plasticity ◽  
Large Scale ◽  
Natural Populations ◽  
Moisture Stress ◽  
Climatic Indices ◽  
South Eastern ◽  
Moisture Regimes ◽  
Eastern Australia ◽  
South Eastern Australia

Natural populations of Echium plantagineum on an east-west line across south-eastern Australia were sampled on three occasions during the growing season, and seeds collected from individual plants in each population were grown in a common glasshouse. In another experiment seedlings of E. plantagineum were divided and clones from each plant were grown under two soil moisture regimes. Field populations differed significantly in all seven characters measured at all sampling dates but, with one exception, between-population differences were unrelated to five climatic indices. Glasshouse populations differed significantly in 15 of 27 characters; variations in some of these characters were related by regression analysis to one or more of the climatic indices. Clones grown under moisture stress flowered later, had proportionally wider leaves and were smaller than well watered clones. The data suggest that an ecocline has developed, or is developing, in E. plantagineum in south- eastern Australia in response to large-scale and long-term aspects of climate, although extensive genetic variation between individuals in each population was also observed. This species exhibits a great deal of phenotypic plasticity in response to localized environmental factors.

scholarly journals Effects of large fires on biodiversity in south-eastern Australia: disaster or template for diversity?

2008 ◽  
Vol 17 (6) ◽  
pp. 809 ◽  
Author(s):  
Ross A. Bradstock
Keyword(s):  
Large Scale ◽  
Fire Regimes ◽  
Ecological Communities ◽  
South Eastern ◽  
Habitat Variation ◽  
Eastern Australia ◽  
Rate Adaptive ◽  
Large Fires ◽  
South Eastern Australia

Large fires coincident with drought occurred in south-eastern Australia during 2001–2007. Perceptions of large, intense fires as being ecologically ‘disastrous’ are common. These are summarised by four hypotheses characterising large fires as: (i) homogenous in extent and intensity; (ii) causing large-scale extinction due to perceived lack of survival and regeneration capacity among biota; (iii) degrading due to erosion and related edaphic effects; (iv) unnatural, as a consequence of contemporary land management. These hypotheses are examined using available evidence and shown to inadequately account for effects of large fires on biodiversity. Large fires do not burn homogeneously, though they may produce intensely burnt patches and areas. The bulk of biota are resilient through a variety of in situ persistence mechanisms that are reinforced by landscape factors. Severe erosive episodes following fire tend to be local and uncertain rather than global and inevitable. Redistribution of soil and nutrients may reinforce habitat variation in some cases. Signals of fire are highly variable over prehistoric and historic eras, and, in some cases, contemporary and pre-European signal levels are equivalent. The most important effects of large fires in these diverse ecological communities and landscapes stem from their recurrence rate. Adaptive management of fire regimes rather than fire events is required, based on an understanding of risks posed by particular regimes to biota.

scholarly journals Prospects for improving perennial legume persistence in mixed grazed pastures of south-eastern Australia, with particular reference to white clover

2019 ◽  
Vol 70 (12) ◽  
pp. 1141 ◽  
Author(s):  
R. C. Hayes ◽  
I. Ara ◽  
W. B. Badgery ◽  
R. A. Culvenor ◽  
R. E. Haling ◽  
...  
Keyword(s):  
Soil Fertility ◽  
White Clover ◽  
Genetic Improvement ◽  
Moisture Stress ◽  
Nutrient Deficiencies ◽  
Seedling Regeneration ◽  
South Eastern ◽  
Eastern Australia ◽  
Perennial Legume ◽  
South Eastern Australia

This review examines the prospect of improving perennial legume adaptation to grazed mixed pasture swards across the higher-altitude regions of south-eastern Australia through improved management, particularly as it relates to soil fertility. The range of adapted perennial species available to farmers often remains limited to only one perennial forage legume species, white clover (Trifolium repens L.). Despite recent advances in cultivars for increased persistence in dryland environments, white clover remains sensitive to drought with its inherently shallow root system and limited capacity to restrict water loss from herbage. With few alternative species likely to become widely available in the foreseeable future, prospects for extending the boundaries of perennial legume adaptation likely rely on a dual approach of improving soil fertility and further genetic improvement in white clover. Improved soil fertility would focus on overcoming soil acidity and addressing nutrient deficiencies, particularly of phosphorus, potassium, boron and molybdenum, which tend to be more widespread in the target region. Addressing these soil constraints would alleviate periodic moisture stress by: (1) increased water availability through improved infiltration and soil hydraulic properties; (2) increased root growth to maximise exploration of the soil volume; and (3) better maintenance of plant cell structures to foster improved osmotic regulation. However, the extent to which white clover adaption may be extended remains an issue of further research. This review highlights an opportunity for further genetic improvement of white clover by focusing on improving the capacity to recover from periodic droughts through seedling regeneration. Further breeding efforts in white clover should examine the feasibility of selecting for hard seed characteristics more similar to the best-adapted subterranean clover (Trifolium subterraneum L.) cultivars across this region to promote ongoing seedling regeneration.

Allozyme and mitochondrial DNA analysis of carp, Cyprinus carpio L., from south-eastern Australia

1999 ◽  
Vol 50 (3) ◽  
pp. 253 ◽  
Author(s):  
Karyn M. Davis ◽  
Patricia I. Dixon ◽  
John H. Harris
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Variation ◽  
Cyprinus Carpio ◽  
Dna Analysis ◽  
Restriction Enzymes ◽  
South Eastern ◽  
Eastern Australia ◽  
Carp Cyprinus Carpio ◽  
Allozyme Loci ◽  
South Eastern Australia

Carp (Cyprinus carpio L.) were introduced to Australia on at least three occasions over the past 100 years. These introductions were to the Prospect Reservoir, Sydney (1907), the Murrumbidgee Irrigation Area, New South Wales (NSW) (1940s), and to Boolarra, Victoria (1960). Koi, a colourful variety of carp, have been introduced to several areas as well. Carp are now widely spread throughout south-eastern Australia. This study aimed to investigate genetic variation of carp in south-eastern Australia. Carp from several localities were examined at seven polymorphic allozyme loci and with three restriction enzymes detecting polymorphic sites in mitochondrial DNA. Three composite mtDNA haplotypes were found. Haplotype 1 was spread throughout the study area, occurring in 72% of all individuals examined. Haplotype 2 was localized to south-western NSW and occurred in 4% of individuals. Haplotype 3 was found in the Australian Capital Territory and Tasmania and accounted for 24% of individuals. Little genetic variation within and among carp populations was observed in the mitochondrial DNA data. The allozyme data showed greater variation within populations than did the mitochondrial DNA data.

Can outbreaks of house mice in south-eastern Australia be predicted by weather models?

2004 ◽  
Vol 31 (5) ◽  
pp. 465 ◽  
Author(s):  
Charles J. Krebs ◽  
Alice J. Kenney ◽  
Grant R. Singleton ◽  
Greg Mutze ◽  
Roger P. Pech ◽  
...  
Keyword(s):  
Large Scale ◽  
Southern Oscillation ◽  
Plant Production ◽  
House Mice ◽  
Weather Variables ◽  
Mouse Population ◽  
Enso Events ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Outbreaks of house mice (Mus domesticus) occur irregularly in the wheat-growing areas of south-eastern Australia, and are thought to be driven by weather variability, particularly rainfall. If rainfall drives grass and seed production, and vegetation production drives mouse dynamics, we should achieve better predictability of mouse outbreaks by the use of plant-production data. On a broader scale, if climatic variability is affected by El Niño–Southern Oscillation (ENSO) events, large-scale weather variables might be associated with mouse outbreaks. We could not find any association of mouse outbreaks over the last century with any ENSO measurements or other large-scale weather variables, indicating that the causal change linking mouse numbers with weather variation is more complex than is commonly assumed. For the 1960–2002 period we were only partly successful in using variation in cereal production to predict outbreaks of mice in nine areas of Victoria and South Australia, and we got better predictability of outbreaks from rainfall data alone. We achieved 70% correct predictions for a qualitative model using rainfall and 58% for a quantitative model using rainfall and spring mouse numbers. Without the detailed specific mechanisms underlying mouse population dynamics, we may not be able to improve on these simple models that link rainfall to mouse outbreaks.

Evidence of large-scale spatial declines in recruitment patterns of southern rock lobster Jasus edwardsii, across south-eastern Australia

2010 ◽  
Vol 105 (3) ◽  
pp. 163-171 ◽  
Author(s):  
Adrian Linnane ◽  
Caleb Gardner ◽  
David Hobday ◽  
André Punt ◽  
Richard McGarvey ◽  
...  
Keyword(s):  
Large Scale ◽  
Rock Lobster ◽  
South Eastern ◽  
Eastern Australia ◽  
Jasus Edwardsii ◽  
Recruitment Patterns ◽  
South Eastern Australia

Genetic variation and phylogeography of the Australian and New Zealand fern Asplenium flabellifolium (Aspleniaceae)

2020 ◽  
Author(s):  
Daniel J. Ohlsen ◽  
Lara D. Shepherd ◽  
Leon R. Perrie ◽  
Patrick J. Brownsey ◽  
Michael J. Bayly
Keyword(s):  
Genetic Variation ◽  
New Zealand ◽  
Breeding System ◽  
Taxonomic Revision ◽  
Morphological Features ◽  
South Eastern ◽  
Tasman Sea ◽  
Eastern Australia ◽  
South Eastern Australia

Asplenium flabellifolium Cav. is a cytologically variable Australian and New Zealand fern. Here, we sequence chloroplast trnL-trnF and rps4-trnS from samples throughout its range to provide the first phylogeographic investigation of a fern common in both countries. Twenty-three haplotypes were detected, which formed six haplogroups in a network. Australian specimens were placed in all haplogroups. The placement of New Zealand haplotypes in five of the haplogroups suggests that this species has dispersed across the Tasman Sea at least five times. Sexually reproducing plants of lower ploidy, detected only in south-eastern Australia, contained haplotypes from the two haplogroups that are successive sisters to the remaining diversity in the phylogeny. This likely suggests that A. flabellifolium was originally a sexually reproducing species in south-eastern Australia and spread to the rest of its distribution where apomictic plants dominate. More than one haplogroup was detected in several areas across its distribution, suggesting that these areas were colonised several times. Other areas harboured several haplotypes from a single haplogroup or haplogroups not recovered elsewhere, indicating possible long-term persistence in these areas. Haplotypes and morphological features were not found to be exclusive to either breeding system or ploidy and no taxonomic revision is proposed.

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