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Species-level determination of closely related araucarian resins using FTIR spectroscopy and its implications for the provenance of New Zealand amber.

Seyfullah LJ, Sadowski EM, Schmidt AR - PeerJ (2015)

Bottom Line: Here we focus on resins produced from today's most resinous conifer family, the Araucariaceae, which are thought to be the parent plants of some of the Southern Hemisphere's fossil resin deposits.The resin FTIR spectra are distinguishable from each other, and the three Araucaria species sampled produced similar FTIR spectra, to which Wollemia resin is most similar.Interspecific variability of the FTIR spectra is greatest in the three Agathis species tested.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Geobiology, University of Göttingen , Göttingen , Germany.

ABSTRACT
Some higher plants, both angiosperms and gymnosperms, can produce resins and some of these resins can polymerize and fossilize to form ambers. Various physical and chemical techniques have been used to identify and profile different plant resins and have then been applied to fossilized resins (ambers), to try to detect their parent plant affinities and understand the process of polymerization, with varying levels of success. Here we focus on resins produced from today's most resinous conifer family, the Araucariaceae, which are thought to be the parent plants of some of the Southern Hemisphere's fossil resin deposits. Fourier transform infrared (FTIR) spectra of the resins of closely related Araucariaceae species were examined to test whether they could be distinguished at genus and species level and whether the results could then be used to infer the parent plant of a New Zealand amber. The resin FTIR spectra are distinguishable from each other, and the three Araucaria species sampled produced similar FTIR spectra, to which Wollemia resin is most similar. Interspecific variability of the FTIR spectra is greatest in the three Agathis species tested. The New Zealand amber sample is similar in key shared features with the resin samples, but it does differ from the extant resin samples in key distinguishing features, nonetheless it is most similar to the resin of Agathis australis in this dataset. However on comparison with previously published FTIR spectra of similar aged amber and older (Eocene) resinites both found in coals from New Zealand and fresh Agathis australis resin, our amber has some features that imply a relatively immature resin, which was not expected from an amber of the Miocene age.

No MeSH data available.


Map of New Zealand and close-up of Otago with Idaburn amber locality (red dot) indicated.
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fig-1: Map of New Zealand and close-up of Otago with Idaburn amber locality (red dot) indicated.

Mentions: Seven resins from across the Araucariaceae were sampled from wild and cultivated specimens (Table 1). All except the Araucaria heterophylla and the Wollemia nobilis resins were collected in New Caledonia and New Zealand in 2011, with the two excepted resins collected in 2014. Fieldwork and collection in southern New Caledonia were kindly permitted by the Direction de l’Environnement (Province Sud), permit no. 17778/DENV/SCB delivered in November 2011. Samples were preferentially collected from trunks, if available, but exudates from branches were used if trunk exudates were not available (Table 1). Hardened resin was preferred, but in two cases (W. nobilis and Ar. heterophylla) semi-solidified resin was collected and prepared. A sample of amber from the early Miocene Idaburn locality in southern New Zealand (Fig. 1) was also tested (see geological information for the amber specimen below). This single large piece of amber was collected in October 2011 and is housed at the Geology Museum of the University of Otago in Dunedin, collection number OU 33159.1. All samples without inclusions or any observable contaminants were chosen, freshly fractured and reduced to a fine powder for application to the central measuring point of the FTIR spectrometer, only tens of micrograms of samples are required per test. Pelletization with KBr was not necessary as the Attenuated Total Reflectance (ATR) technique was used. The absorption spectra were collected in the range 4000–650 cm−1 (wavenumbers), equivalent to 2.5–15 µm, using a Jasco 4,100 Fourier transform infrared (FTIR) spectrometer. Spectral resolution was set at 4 cm−1. Multiple replicate tests were run per sample until at least three spectra when overlaid were exactly the same, and each time new portions of the ground samples were used. The baseline was not corrected. Bands were identified by comparison with previous reports (e.g., Lyons, Masterlerz & Orem, 2009; Tappert et al., 2011).


Species-level determination of closely related araucarian resins using FTIR spectroscopy and its implications for the provenance of New Zealand amber.

Seyfullah LJ, Sadowski EM, Schmidt AR - PeerJ (2015)

Map of New Zealand and close-up of Otago with Idaburn amber locality (red dot) indicated.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493646&req=5

fig-1: Map of New Zealand and close-up of Otago with Idaburn amber locality (red dot) indicated.
Mentions: Seven resins from across the Araucariaceae were sampled from wild and cultivated specimens (Table 1). All except the Araucaria heterophylla and the Wollemia nobilis resins were collected in New Caledonia and New Zealand in 2011, with the two excepted resins collected in 2014. Fieldwork and collection in southern New Caledonia were kindly permitted by the Direction de l’Environnement (Province Sud), permit no. 17778/DENV/SCB delivered in November 2011. Samples were preferentially collected from trunks, if available, but exudates from branches were used if trunk exudates were not available (Table 1). Hardened resin was preferred, but in two cases (W. nobilis and Ar. heterophylla) semi-solidified resin was collected and prepared. A sample of amber from the early Miocene Idaburn locality in southern New Zealand (Fig. 1) was also tested (see geological information for the amber specimen below). This single large piece of amber was collected in October 2011 and is housed at the Geology Museum of the University of Otago in Dunedin, collection number OU 33159.1. All samples without inclusions or any observable contaminants were chosen, freshly fractured and reduced to a fine powder for application to the central measuring point of the FTIR spectrometer, only tens of micrograms of samples are required per test. Pelletization with KBr was not necessary as the Attenuated Total Reflectance (ATR) technique was used. The absorption spectra were collected in the range 4000–650 cm−1 (wavenumbers), equivalent to 2.5–15 µm, using a Jasco 4,100 Fourier transform infrared (FTIR) spectrometer. Spectral resolution was set at 4 cm−1. Multiple replicate tests were run per sample until at least three spectra when overlaid were exactly the same, and each time new portions of the ground samples were used. The baseline was not corrected. Bands were identified by comparison with previous reports (e.g., Lyons, Masterlerz & Orem, 2009; Tappert et al., 2011).

Bottom Line: Here we focus on resins produced from today's most resinous conifer family, the Araucariaceae, which are thought to be the parent plants of some of the Southern Hemisphere's fossil resin deposits.The resin FTIR spectra are distinguishable from each other, and the three Araucaria species sampled produced similar FTIR spectra, to which Wollemia resin is most similar.Interspecific variability of the FTIR spectra is greatest in the three Agathis species tested.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Geobiology, University of Göttingen , Göttingen , Germany.

ABSTRACT
Some higher plants, both angiosperms and gymnosperms, can produce resins and some of these resins can polymerize and fossilize to form ambers. Various physical and chemical techniques have been used to identify and profile different plant resins and have then been applied to fossilized resins (ambers), to try to detect their parent plant affinities and understand the process of polymerization, with varying levels of success. Here we focus on resins produced from today's most resinous conifer family, the Araucariaceae, which are thought to be the parent plants of some of the Southern Hemisphere's fossil resin deposits. Fourier transform infrared (FTIR) spectra of the resins of closely related Araucariaceae species were examined to test whether they could be distinguished at genus and species level and whether the results could then be used to infer the parent plant of a New Zealand amber. The resin FTIR spectra are distinguishable from each other, and the three Araucaria species sampled produced similar FTIR spectra, to which Wollemia resin is most similar. Interspecific variability of the FTIR spectra is greatest in the three Agathis species tested. The New Zealand amber sample is similar in key shared features with the resin samples, but it does differ from the extant resin samples in key distinguishing features, nonetheless it is most similar to the resin of Agathis australis in this dataset. However on comparison with previously published FTIR spectra of similar aged amber and older (Eocene) resinites both found in coals from New Zealand and fresh Agathis australis resin, our amber has some features that imply a relatively immature resin, which was not expected from an amber of the Miocene age.

No MeSH data available.