The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform
Per E Christensen - One of the best experts on this subject based on the ideXlab platform.
-
total fluorine analysis of seed of australian Gastrolobium spp showing temporal spatial and morphological variation
Journal of Fluorine Chemistry, 2007Co-Authors: David Peacock, Brian Williams, Per E ChristensenAbstract:Abstract Alkali-fusion in conjunction with a fluoride selective electrode were used to quantify ‘total fluorine’, being organic fluorine + inorganic fluoride, for the seed of 13 species of Gastrolobium from south–west Western Australia. Intact seed covering spatial and temporal distributions, as well as G. bilobum , G. calycinum and G. parviflorum seed dissected into cotyledons and testa + aril, were analysed. Analysis found significant intra-and inter-species variation, both temporally and spatially, with intact seed concentrations ranging from 1.6 ± 0.3 mg kg −1 in G. spinosum from Mundaring to 1063.9 ± 77.8 mg kg −1 for G. cuneatum from Torbay. Approximately 87% of the ‘total fluorine’ was found to be in the seed cotyledons. Additional analysis detected little inorganic fluoride, indicating the majority of fluorine in the seed is organically bound. Parent compound(s) of the fluorine, seed toxicity and the implications of the results for seed chemical defense are discussed.
-
1080 toxic sugars alkaloids and a dead cat the search for a toxicant in australian Gastrolobium seed
Proceedings of the Vertebrate Pest Conference, 2004Co-Authors: David Peacock, Bryan Williams, Thomas Spande, Per E ChristensenAbstract:Author(s): Peacock, David; Williams, Bryan; Spande, Thomas; Christensen, Per | Abstract: It was hypothesised that reintroduction of Australian native mammals, currently being severely impacted by feral cat predation, would be more successful if these mammals could have a retained toxicity as discussed in historical accounts. Seeds from the Australian genus Gastrolobium (Fabaceae: Mirbelieae) were analysed in the search for a toxicant that would explain historical accounts of toxic wildlife. Numerous accounts referring to bronzewing pigeons having toxic bones were specifically noted. Analysis of this seed found no evidence for rapidly toxic alkaloids previously reported as being extracted from the leaves of York Road poison and box poison. However, evidence for the presence of organo-fluorine compounds in addition to the reported fluoroacetate (Compound 1080) was discovered. A limited cat dosing trial found that a highly fluorinated box poison seed caused a cat to cease respiration in 82 minutes, but its chloroform extract produced no adverse physiological response. In addition, citrate accumulation appeared more rapid and acute with increasing seed ‘total fluorine.’
-
the search for a toxicant in native Gastrolobium seed historically reported to make australian native fauna toxic to the introduced cat and dog
Proceedings of the Vertebrate Pest Conference, 2002Co-Authors: David Peacock, Brian Williams, Per E ChristensenAbstract:Author(s): Peacock, David; Williams, Brian; Christensen, Per | Abstract: The decline and extinction of Australian mammals since the arrival of Europeans has been catastrophic. Attempts to reintroduce threatened species of native mammals to their former ranges have failed due to predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis silvestris catus). Baiting with poisoned meat baits will control foxes, but feral cats are generally unwilling to consume a bait. This has seen recent reintroduction attempts fail due to cat predation, possibly involving only a few individual animals. Historical anecdotes from Western Australia record the death of cats and dogs after feeding on a number of the native animal species, with the bronzewing pigeons, Phaps chalcoptera and P. elegans, most frequently mentioned. The toxicity of the pigeons has been attributed to the birds’ feeding on seeds from plants of the Gastrolobium genus. Such a mechanism has been suggested to have aided the survival of 35- to 5,500-g mammals in southwest Western Australia when such species have disappeared elsewhere. Analysis of the seeds of members of the genus Gastrolobium has found extremely high levels of organically bound fluorine. Previous studies report this fluorine to be stored in the seeds as monofluoroacetate (MFA – synonymous with Compound 1080). However, a number of the poisoning anecdotes suggest toxicity of the pigeon skeleton, and report times to death which appear too rapid for the known action of MFA or “1080.” The objective of this research is to examine the authenticity of the historical anecdotes and the feasibility of using a skeletally retained natural plant toxicant to aid the reintroduction of native fauna. Those individual cats and foxes effecting the predation may be removed at the first predatory event if the reintroduced fauna were toxic to the predating animal. This is anticipated to greatly improve the success rate of future reintroduction programs. Exhaustive extraction of Gastrolobium seeds with a variety of solvents and subsequent analysis utilizing a fluoride ion-specific electrode, 19F nuclear magnetic resonance, and other techniques has established the presence of a number of fluorinated and alkaloid compounds. Determination of the identity and toxicity of these compounds is expected to identify a compound(s) which may explain many of the historical poisoning anecdotes and could also provide a method for the control of feral cats in native mammal reintroduction programs.
Michael D. Crisp - One of the best experts on this subject based on the ideXlab platform.
-
Molecular Evidence for Definition of Genera in the Oxylobium Group (Fabaceae: Mirbelieae)
Systematic Botany, 2009Co-Authors: Michael D. Crisp, Lyn G. CookAbstract:The circumscription of Oxylobium and related genera has been problematic for nearly 200 years. Traditional definitions of genera in the group have relied on morphological features of the leaves, flower, and fruit that overlap extensively between genera. Therefore sequences of cpDNA (trnL-F intron and spacer) and nrDNA (ITS) were used to estimate the phylogeny of the group in an attempt to redefine the genera as monophyletic groups. Oxylobium sens. str. was found to be a well supported clade in both data sets, with the inclusion of Mirbelia oxylobioides. No other genus in the group was supported by these data, except Gastrolobium sens. lat. Some species groups within Chorizema, Mirbelia, and Podolobium were supported but relationships among these, Oxylobium and Gastrolobium differed significantly between the chloroplast and nuclear data sets. No group supported by the molecular data had a morphological synapomorphy, not even Oxylobium or Gastrolobium. Therefore it may be necessary to adopt a much broader generic concept in this group than has been done previously. Incongruence between the two molecular data sets, and very short internal basal branches in both, suggest a rapid early radiation in this group, possibly combined with hybridization and lineage sorting.
-
monograph of Gastrolobium fabaceae mirbelieae
Australian Systematic Botany, 2002Co-Authors: Gregory T Chandler, Michael D. Crisp, Lindy Cayzer, Randall J BayerAbstract:A taxonomic revision with full descriptions and key are presented for the 109 known species of Gastrolobium, including 29 new species described here for the first time. Brachysema, Jansonia and Nemcia are formally placed into Gastrolobium and new combinations have been made where necessary. Included in the revision are full taxonomic descriptions for all species, full synonymies, literature references for original publications, typification, including selection of lectotypes where necessary, distributions complete with maps, and taxonomic and nomenclatural notes. New taxa described herein are G. acrocaroli, G. aculeatum, G. alternifolium, G. congestum, G. crispatum, G. cruciatum, G. cyanophyllum, G. diabolophyllum, G. discolor, G. elegans, G. euryphyllum, G. ferrugineum, G. glabratum, G. hians, G. humile, G. involutum, G. melanopetalum, G. mondurup, G. musaceum, G. nudum, G. nutans, G. reflexum, G. rhombifolium, G. semiteres, G. tenue, G. tergiversum, G. venulosum, G. whicherensis and G. wonganensis.
-
A molecular phylogeny of the endemic Australian genus Gastrolobium (Fabaceae: Mirbelieae) and allied genera using chloroplast and nuclear markers
American journal of botany, 2001Co-Authors: Gregory T Chandler, Randall J Bayer, Michael D. CrispAbstract:Gastrolobium (Fabaceae: Mirbelieae) is an endemic Australian genus that produces toxic sodium monofluoroacetate. A phylogenetic reconstruction of Gastrolobium and the related genera Brachysema, Callistachys, Jansonia, Nemcia, Oxylobium,and Podolobium is presented, using sequence data from three regions—the psbA-trnH intergenic spacer and the trnK 59 intron from chloroplast DNA and the 39 end of the external transcribed spacer (ETS) from nuclear ribosomal DNA. Gastrolobium is shown to be paraphyletic, with Brachysema, Jansonia, Nemcia,and Oxylobium linearenesting within it, and Nemcia is shown to be polyphyletic within Gastrolobium. Past key morphological characters, such as fluoroacetate content and characters associated with pollination syndrome, are shown to be homoplastic, with fluoroacetate possibly a plesiomorphic condition lost in more derived species. Podolobium is also shown to be polyphyletic, with the P. ilicifolium group sister to Gastrolobium and the P. alpestre group sister to Callistachys, a member of the Oxylobium group. It is recommended that Gastrolobiumbe expanded to include Brachysema, Jansonia, Nemcia,and Oxylobium lineare, while further work is required to test the sister-group relationship between Podolobium s.s. (sensu stricto) and Gastrolobium.
David Peacock - One of the best experts on this subject based on the ideXlab platform.
-
total fluorine analysis of seed of australian Gastrolobium spp showing temporal spatial and morphological variation
Journal of Fluorine Chemistry, 2007Co-Authors: David Peacock, Brian Williams, Per E ChristensenAbstract:Abstract Alkali-fusion in conjunction with a fluoride selective electrode were used to quantify ‘total fluorine’, being organic fluorine + inorganic fluoride, for the seed of 13 species of Gastrolobium from south–west Western Australia. Intact seed covering spatial and temporal distributions, as well as G. bilobum , G. calycinum and G. parviflorum seed dissected into cotyledons and testa + aril, were analysed. Analysis found significant intra-and inter-species variation, both temporally and spatially, with intact seed concentrations ranging from 1.6 ± 0.3 mg kg −1 in G. spinosum from Mundaring to 1063.9 ± 77.8 mg kg −1 for G. cuneatum from Torbay. Approximately 87% of the ‘total fluorine’ was found to be in the seed cotyledons. Additional analysis detected little inorganic fluoride, indicating the majority of fluorine in the seed is organically bound. Parent compound(s) of the fluorine, seed toxicity and the implications of the results for seed chemical defense are discussed.
-
1080 toxic sugars alkaloids and a dead cat the search for a toxicant in australian Gastrolobium seed
Proceedings of the Vertebrate Pest Conference, 2004Co-Authors: David Peacock, Bryan Williams, Thomas Spande, Per E ChristensenAbstract:Author(s): Peacock, David; Williams, Bryan; Spande, Thomas; Christensen, Per | Abstract: It was hypothesised that reintroduction of Australian native mammals, currently being severely impacted by feral cat predation, would be more successful if these mammals could have a retained toxicity as discussed in historical accounts. Seeds from the Australian genus Gastrolobium (Fabaceae: Mirbelieae) were analysed in the search for a toxicant that would explain historical accounts of toxic wildlife. Numerous accounts referring to bronzewing pigeons having toxic bones were specifically noted. Analysis of this seed found no evidence for rapidly toxic alkaloids previously reported as being extracted from the leaves of York Road poison and box poison. However, evidence for the presence of organo-fluorine compounds in addition to the reported fluoroacetate (Compound 1080) was discovered. A limited cat dosing trial found that a highly fluorinated box poison seed caused a cat to cease respiration in 82 minutes, but its chloroform extract produced no adverse physiological response. In addition, citrate accumulation appeared more rapid and acute with increasing seed ‘total fluorine.’
-
the search for a toxicant in native Gastrolobium seed historically reported to make australian native fauna toxic to the introduced cat and dog
Proceedings of the Vertebrate Pest Conference, 2002Co-Authors: David Peacock, Brian Williams, Per E ChristensenAbstract:Author(s): Peacock, David; Williams, Brian; Christensen, Per | Abstract: The decline and extinction of Australian mammals since the arrival of Europeans has been catastrophic. Attempts to reintroduce threatened species of native mammals to their former ranges have failed due to predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis silvestris catus). Baiting with poisoned meat baits will control foxes, but feral cats are generally unwilling to consume a bait. This has seen recent reintroduction attempts fail due to cat predation, possibly involving only a few individual animals. Historical anecdotes from Western Australia record the death of cats and dogs after feeding on a number of the native animal species, with the bronzewing pigeons, Phaps chalcoptera and P. elegans, most frequently mentioned. The toxicity of the pigeons has been attributed to the birds’ feeding on seeds from plants of the Gastrolobium genus. Such a mechanism has been suggested to have aided the survival of 35- to 5,500-g mammals in southwest Western Australia when such species have disappeared elsewhere. Analysis of the seeds of members of the genus Gastrolobium has found extremely high levels of organically bound fluorine. Previous studies report this fluorine to be stored in the seeds as monofluoroacetate (MFA – synonymous with Compound 1080). However, a number of the poisoning anecdotes suggest toxicity of the pigeon skeleton, and report times to death which appear too rapid for the known action of MFA or “1080.” The objective of this research is to examine the authenticity of the historical anecdotes and the feasibility of using a skeletally retained natural plant toxicant to aid the reintroduction of native fauna. Those individual cats and foxes effecting the predation may be removed at the first predatory event if the reintroduced fauna were toxic to the predating animal. This is anticipated to greatly improve the success rate of future reintroduction programs. Exhaustive extraction of Gastrolobium seeds with a variety of solvents and subsequent analysis utilizing a fluoride ion-specific electrode, 19F nuclear magnetic resonance, and other techniques has established the presence of a number of fluorinated and alkaloid compounds. Determination of the identity and toxicity of these compounds is expected to identify a compound(s) which may explain many of the historical poisoning anecdotes and could also provide a method for the control of feral cats in native mammal reintroduction programs.
Laurie E. Twigg - One of the best experts on this subject based on the ideXlab platform.
-
Fluoroacetate-bearing vegetation: Can it reduce the impact of exotic mammals on wildlife conservation?
Pacific Conservation Biology, 2011Co-Authors: Laurie E. TwiggAbstract:There is no doubt that fluoroacetate-bearing vegetation (also known as poison peas) has had a profound effect on the evolution and persistence of Western Australian biota. Most of these plants belong to the genus Gastrolobium, and most are found in the south-west corner of Western Australia (Gardner and Bennetts 1956; Aplin 1971; Twigg and King 1991). The toxic principle of these plants, fluoroacetate, is also manufactured synthetically as 1080 (sodium fluoroacetate) for Australiawide control of vertebrate pests, such as rabbits Oryctolagus cuniculus, foxes Vulpes vulpes, wild dogs Canis lupus familiaris and feral Pigs Sus scrofa (Twigg and King 1991). Because of their co-evolution with fluoroacetate-bearing vegetation, many native animals in Western Australia have developed varying levels of tolerance to this highly toxic compound. In contrast, introduced mammals are generally highly sensitive to fluoroacetate. Although it is not a prerequisite for safe and effective pest control programmes with 1080, the toxicity differential between native and introduced animals provides an additional "safety net"when using 1080 products in Western Australia.
-
short communication fluoroacetate content of Gastrolobium brevipes in central australia
Australian Journal of Botany, 1999Co-Authors: Laurie E. Twigg, G. R. Wright, Michelle D PottsAbstract:The spectral reflectance of leaves from several Eucalyptus species was measured over the 400–2500 nm wavelengths with a laboratory spectroradiometer. The relationship of reflectance with the gravimetric water content and equivalent water thickness (EWT) of the leaves was analysed. The results showed that EWT was strongly correlated with reflectance in several wavelength regions. No significant correlations could be obtained between reflectance and gravimetric water content. It was also possible to confirm theoretically that reflectance changes of leaves could be directly linked to changes in EWT but not to changes in gravimetric water content. Several existing reflectance indices were evaluated for estimation of leaf water content and some new indices were developed and tested. Two semi-empirical indices developed in this study, (R850 - R2218)/(R850 - R1928) and (R850 - R1788)/(R850 - R1928), were found to show significantly stronger correlations with EWT than all other indices tested. It was also shown that these new indices were least sensitive to the effects of radiation scatter. The indices (R850 - R2218)/(R850 - R1928) and (R850 - R1788)/(R850 - R1928) are therefore proposed as two new indices for the remote estimation of vegetation water content.
-
Fluoroacetate content of some species of the toxic Australian plant genus, Gastrolobium, and its environmental persistence
Natural Toxins, 1996Co-Authors: Laurie E. Twigg, Dennis R. King, Lynn H. Bowen, G. R. Wright, Charles EasonAbstract:Gas chromatography confirmed the relatively high concentrations of fluoroacetate found in toxic Gastrolobiums, a genus of indigenous Australian plants. Fluoroacetate concentration in these plants ranged from 0.1 to 3875 micrograms/g (ppm) dry weight, with young leaves and flowers containing the highest concentrations. However, there was considerable intrastand variation between individual plants of at least two species with coefficients of variation ranging from 94% to 129%. Despite the high concentrations of fluoroacetate in many species, only one of nine soil samples collected from beneath these plants contained fluoroacetate. None of the 16 water samples collected from nearby streams and catchment dams contained fluoroacetate. This suggests that fluoroacetate does not persist in this environment. Fluoroacetate was also found in the genus Nemcia, and very low levels of fluoroacetate (ng/g) were detected in the foodstuffs, tea and guar gum. The latter indicates that other plant species may produce biologically insignificant amounts of fluoroacetate.
Gregory T Chandler - One of the best experts on this subject based on the ideXlab platform.
-
oxylobium Gastrolobium fabaceae mirbelieae conundrum further studies using molecular data and a reappraisal of morphological characters
Plant Species Biology, 2003Co-Authors: Gregory T Chandler, Randall J Bayer, Simon GilmoreAbstract:A molecular phylogeny of Oxylobium , Gastrolobium and related genera, including Brachysema , Jansonia , Nemcia and Podolobium, is presented. The study was conducted using five molecular regions and 48 taxa, utilizing chloroplast DNA (the trn K 5¢¢ intron, psb A/ trn H intergenic spacer, trn L intron and adjacent trn L/ trn F intergenic spacer) and nuclear ribosomal DNA (ETS and ITS) markers. Oxylobium is shown to be polyphyletic, while Gastrolobium is paraphyletic, containing within it the genera Brachysema , Jansonia and Nemcia , as well as Oxylobium lineare . This concurs with a previous molecular analysis and the results of the two analyses are compared. Morphological traits, such as subtending bracts, ovule number and fluoroacetate content, are shown to be homoplastic and suites of characters for defining the different genera using different morphological characters are presented. Our results support a recent monograph that expands Gastrolobium to include Brachysema , Jansonia , Nemcia and Oxylobium lineare . This revision leaves Oxylobium and Podolobium occurring exclusively in eastern Australia, while Gastrolobium occurs almost exclusively in south-western Australia, with only two species, G. brevipes and G. grandiflorum , occurring outside this area.
-
monograph of Gastrolobium fabaceae mirbelieae
Australian Systematic Botany, 2002Co-Authors: Gregory T Chandler, Michael D. Crisp, Lindy Cayzer, Randall J BayerAbstract:A taxonomic revision with full descriptions and key are presented for the 109 known species of Gastrolobium, including 29 new species described here for the first time. Brachysema, Jansonia and Nemcia are formally placed into Gastrolobium and new combinations have been made where necessary. Included in the revision are full taxonomic descriptions for all species, full synonymies, literature references for original publications, typification, including selection of lectotypes where necessary, distributions complete with maps, and taxonomic and nomenclatural notes. New taxa described herein are G. acrocaroli, G. aculeatum, G. alternifolium, G. congestum, G. crispatum, G. cruciatum, G. cyanophyllum, G. diabolophyllum, G. discolor, G. elegans, G. euryphyllum, G. ferrugineum, G. glabratum, G. hians, G. humile, G. involutum, G. melanopetalum, G. mondurup, G. musaceum, G. nudum, G. nutans, G. reflexum, G. rhombifolium, G. semiteres, G. tenue, G. tergiversum, G. venulosum, G. whicherensis and G. wonganensis.
-
A molecular phylogeny of the endemic Australian genus Gastrolobium (Fabaceae: Mirbelieae) and allied genera using chloroplast and nuclear markers
American journal of botany, 2001Co-Authors: Gregory T Chandler, Randall J Bayer, Michael D. CrispAbstract:Gastrolobium (Fabaceae: Mirbelieae) is an endemic Australian genus that produces toxic sodium monofluoroacetate. A phylogenetic reconstruction of Gastrolobium and the related genera Brachysema, Callistachys, Jansonia, Nemcia, Oxylobium,and Podolobium is presented, using sequence data from three regions—the psbA-trnH intergenic spacer and the trnK 59 intron from chloroplast DNA and the 39 end of the external transcribed spacer (ETS) from nuclear ribosomal DNA. Gastrolobium is shown to be paraphyletic, with Brachysema, Jansonia, Nemcia,and Oxylobium linearenesting within it, and Nemcia is shown to be polyphyletic within Gastrolobium. Past key morphological characters, such as fluoroacetate content and characters associated with pollination syndrome, are shown to be homoplastic, with fluoroacetate possibly a plesiomorphic condition lost in more derived species. Podolobium is also shown to be polyphyletic, with the P. ilicifolium group sister to Gastrolobium and the P. alpestre group sister to Callistachys, a member of the Oxylobium group. It is recommended that Gastrolobiumbe expanded to include Brachysema, Jansonia, Nemcia,and Oxylobium lineare, while further work is required to test the sister-group relationship between Podolobium s.s. (sensu stricto) and Gastrolobium.
