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Kushan U Tennakoon - One of the best experts on this subject based on the ideXlab platform.
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xylem transfer of organic solutes in Santalum album l indian sandalwood in association with legume and non legume hosts
Annals of Botany, 1998Co-Authors: Andrew M. Radomiljac, John S. Pate, Kushan U Tennakoon, J A MccombAbstract:Indian sandalwood (Santalum album), a commercially important root hemi-parasitic angiosperm, was partnered singly in pot culture with one of three nitrogen-fixing legumes or a eucalypt host. Xylem (tracheal) sap of stems of host and parasite and ethanolic extracts of endophytic tissue of haustoria of the parasite were analysed for amino acids, organic acids and sugars to determine which sets of solutes were available to and obtained by the parasite from different hosts. There were high concentrations of asparagine, followed by glutamate, aspartate and γ-amino butyrate in the xylem sap solutes of the three legume hosts (Sesbania formosa, Acacia trachycarpa and A. ampliceps) and much higher levels of glutamate, aspartate, glutamine and arginine in the non-legume, Eucalyptus camaldulensis. Close resemblances between Santalum and legume hosts in concentration and composition of xylem sap amino acids, and in the amino acid spectra of the corresponding parasite endophytic tissue, indicated substantial direct intake of xylem N by Santalum from these hosts. By contrast, low N levels in xylem sap of E. camaldulensis and dissimilarities between its amino acid composition and that of partnered Santalum indicated that the parasite obtained little N from the xylem sap of this host. Xylem sap of hosts contained variable amounts of sucrose. glucose and fructose, whereas that of matching parasites was dominated by fructose. Dissimilarities were also evident in the proportional amounts of xylem-borne organic acids between hosts and parasite particularly for the eucalypt: Santalum partnership. Leaf extracts of the host: parasite pairings generally showed substantial differences in sugar and organic acid balance between partner species. Similarly, where amino acid spectra of host and parasite xylem sap and corresponding haustorial endophytes were closely similar, respective leaf compositions were markedly dissimilar. This implied that substantial metabolic patterns of incoming xylem solutes were highly idiosyncratic of the species in question. Data are related to previous information showing superior growth performance and higher photosynthetic rates and foliar N concentrations in Santalum partnered with the three legumes than with the eucalypt.
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haustorium related uptake and metabolism of host xylem solutes by the root hemiparasitic shrub Santalum acuminatum r br a dc santalaceae
Annals of Botany, 1997Co-Authors: Kushan U Tennakoon, John S. Pate, George R StewartAbstract:Abstract Solute composition of root xylem sap of common native hosts of quandong ( Santalum acuminatum ) was compared with that of corresponding xylem sap and ethanolic extracts of endophytic tissues of haustoria of the hemiparasite. Each host transported a characteristic set of organic nitrogenous solutes, but little or no nitrate, and the data indicated only limited direct flow of amino compounds between xylem streams of hosts and parasite. Proline predominated in the haustorium and xylem of Santalum , but was at negligible levels in the xylem of most hosts. Sucrose, fructose, glucose, malate and citrate were at high levels in all saps, and fructose especially prominent in Santalum . Chloride, sulphate and phosphate were the principal inorganic anions of the xylem. Based on C:N ratios of xylem and dry matter of Santalum and assuming a 70% or more dependence on the host for N, it was estimated that Santalum would gain approximately one third of its C requirement for dry matter production heterotrophically from the xylem of its hosts. Infiltration of xylem of haustoria-bearing root segments of a major host ( Acacia rostellifera ) with a range of 15 N labelled substrates resulted in 40–80% of the 15 N of endophytes of the attached haustoria being received as proline. Nitrate reductase activity was induced in haustoria following host xylem feeding of nitrate. The study concludes that haustoria of Santalum act as a major site of synthesis and export of proline and might therefore play an important role in osmotic adjustment of the parasite and its related acquisition of water from hosts.
John S. Pate - One of the best experts on this subject based on the ideXlab platform.
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Heterotrophic carbon gain and mineral nutrition of the root hemi-parasite Santalum album L. in pot culture with different hosts.
Australian Forestry, 1999Co-Authors: Andrew M. Radomiljac, Jen A. Mccomb, John S. PateAbstract:Summary This paper examines heterotrophic gain of carbon and mineral composition of Santalum album partnered singly in pot culture with three beneficial woody N2-fixing hosts and a non-beneficial eucalypt host. Based on dry matter gains of the parasite at 33 weeks, Sesbania formosa proved the best host followed by Acacia ampliceps and A. trachycarpa while no improvement in growth was seen with Eucalyptus camaldulensis as a host in comparison with Santalum grown without a host. Numbers of haustoria formed by Santalum on roots of different hosts were poorly correlated with host quality. A small proportion of haustoria on legume hosts were attached to root nodules. Santalum partnered with any host or grown alone exhibited self-parasitism where haustoria attached to its own root system. Based on net C and N gains of Santalum and the C: N ratios of xylem solutes of Santalum, the heterotrophic gains of C from xylem of the three beneficial legume hosts over a nine week period were equivalent to 57.9% of total ca...
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GAS EXCHANGE AND WATER RELATIONS OF THE ROOT HEMI-PARASITE Santalum ALBUM L. IN ASSOCIATION WITH LEGUME AND NON-LEGUME HOSTS
Annals of Botany, 1999Co-Authors: Andrew M. Radomiljac, Jen A. Mccomb, John S. PateAbstract:This paper examines foliar nitrogen (N) levels, photosynthesis, transpiration, water use efficiency and tissue water relations of the xylem-tapping root hemi-parasite Santalum album in pot culture with various N2-fixing woody hosts, a non-fixing host (a eucalypt), or in the absence of a host. Foliar N concentrations of Santalum were significantly greater than corresponding hosts and higher when on N2-fixing hosts than on the eucalypt, or without a host. Strong positive relationships were evident in Santalum between foliar N concentration, rates of net photosynthesis and instantaneous water use efficiencies. Photosynthesis rate and water use efficiency of Santalum were generally lower than in corresponding hosts, but transpiration rates were not noticeably different between associations. δ13C values of total shoot dry matter of Santalum were poorly correlated with instantaneous water use efficiency as measured by gas exchange, but associations involving the three legumes showed less negative δ13C values and better water use efficiencies for hosts, than corresponding parasites. Interpretation Of such differences was difficult in view of an earlier demonstration of substantial heterotrophic gain of C from certain hosts. Diurnal profiles of gas exchange and leaf water potential of hosts and parasites indicated closely coordinated diurnal stomatal responses of the parasite water relations to its host, thus resulting in transpiration rates of the parasite generating leaf water potential gradients favouring continuous abstraction of water and nutrients from a host. Tissue water relations of Santalum generally resembled those of water-stress tolerant species. Host-specific effects on relative water content and osmotic adjustment were slight and rated unimportant in regulation of water flow to the parasite, or in protecting it from temporary water stress in a host.
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xylem transfer of organic solutes in Santalum album l indian sandalwood in association with legume and non legume hosts
Annals of Botany, 1998Co-Authors: Andrew M. Radomiljac, John S. Pate, Kushan U Tennakoon, J A MccombAbstract:Indian sandalwood (Santalum album), a commercially important root hemi-parasitic angiosperm, was partnered singly in pot culture with one of three nitrogen-fixing legumes or a eucalypt host. Xylem (tracheal) sap of stems of host and parasite and ethanolic extracts of endophytic tissue of haustoria of the parasite were analysed for amino acids, organic acids and sugars to determine which sets of solutes were available to and obtained by the parasite from different hosts. There were high concentrations of asparagine, followed by glutamate, aspartate and γ-amino butyrate in the xylem sap solutes of the three legume hosts (Sesbania formosa, Acacia trachycarpa and A. ampliceps) and much higher levels of glutamate, aspartate, glutamine and arginine in the non-legume, Eucalyptus camaldulensis. Close resemblances between Santalum and legume hosts in concentration and composition of xylem sap amino acids, and in the amino acid spectra of the corresponding parasite endophytic tissue, indicated substantial direct intake of xylem N by Santalum from these hosts. By contrast, low N levels in xylem sap of E. camaldulensis and dissimilarities between its amino acid composition and that of partnered Santalum indicated that the parasite obtained little N from the xylem sap of this host. Xylem sap of hosts contained variable amounts of sucrose. glucose and fructose, whereas that of matching parasites was dominated by fructose. Dissimilarities were also evident in the proportional amounts of xylem-borne organic acids between hosts and parasite particularly for the eucalypt: Santalum partnership. Leaf extracts of the host: parasite pairings generally showed substantial differences in sugar and organic acid balance between partner species. Similarly, where amino acid spectra of host and parasite xylem sap and corresponding haustorial endophytes were closely similar, respective leaf compositions were markedly dissimilar. This implied that substantial metabolic patterns of incoming xylem solutes were highly idiosyncratic of the species in question. Data are related to previous information showing superior growth performance and higher photosynthetic rates and foliar N concentrations in Santalum partnered with the three legumes than with the eucalypt.
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haustorium related uptake and metabolism of host xylem solutes by the root hemiparasitic shrub Santalum acuminatum r br a dc santalaceae
Annals of Botany, 1997Co-Authors: Kushan U Tennakoon, John S. Pate, George R StewartAbstract:Abstract Solute composition of root xylem sap of common native hosts of quandong ( Santalum acuminatum ) was compared with that of corresponding xylem sap and ethanolic extracts of endophytic tissues of haustoria of the hemiparasite. Each host transported a characteristic set of organic nitrogenous solutes, but little or no nitrate, and the data indicated only limited direct flow of amino compounds between xylem streams of hosts and parasite. Proline predominated in the haustorium and xylem of Santalum , but was at negligible levels in the xylem of most hosts. Sucrose, fructose, glucose, malate and citrate were at high levels in all saps, and fructose especially prominent in Santalum . Chloride, sulphate and phosphate were the principal inorganic anions of the xylem. Based on C:N ratios of xylem and dry matter of Santalum and assuming a 70% or more dependence on the host for N, it was estimated that Santalum would gain approximately one third of its C requirement for dry matter production heterotrophically from the xylem of its hosts. Infiltration of xylem of haustoria-bearing root segments of a major host ( Acacia rostellifera ) with a range of 15 N labelled substrates resulted in 40–80% of the 15 N of endophytes of the attached haustoria being received as proline. Nitrate reductase activity was induced in haustoria following host xylem feeding of nitrate. The study concludes that haustoria of Santalum act as a major site of synthesis and export of proline and might therefore play an important role in osmotic adjustment of the parasite and its related acquisition of water from hosts.
Andrew M. Radomiljac - One of the best experts on this subject based on the ideXlab platform.
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Heterotrophic carbon gain and mineral nutrition of the root hemi-parasite Santalum album L. in pot culture with different hosts.
Australian Forestry, 1999Co-Authors: Andrew M. Radomiljac, Jen A. Mccomb, John S. PateAbstract:Summary This paper examines heterotrophic gain of carbon and mineral composition of Santalum album partnered singly in pot culture with three beneficial woody N2-fixing hosts and a non-beneficial eucalypt host. Based on dry matter gains of the parasite at 33 weeks, Sesbania formosa proved the best host followed by Acacia ampliceps and A. trachycarpa while no improvement in growth was seen with Eucalyptus camaldulensis as a host in comparison with Santalum grown without a host. Numbers of haustoria formed by Santalum on roots of different hosts were poorly correlated with host quality. A small proportion of haustoria on legume hosts were attached to root nodules. Santalum partnered with any host or grown alone exhibited self-parasitism where haustoria attached to its own root system. Based on net C and N gains of Santalum and the C: N ratios of xylem solutes of Santalum, the heterotrophic gains of C from xylem of the three beneficial legume hosts over a nine week period were equivalent to 57.9% of total ca...
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GAS EXCHANGE AND WATER RELATIONS OF THE ROOT HEMI-PARASITE Santalum ALBUM L. IN ASSOCIATION WITH LEGUME AND NON-LEGUME HOSTS
Annals of Botany, 1999Co-Authors: Andrew M. Radomiljac, Jen A. Mccomb, John S. PateAbstract:This paper examines foliar nitrogen (N) levels, photosynthesis, transpiration, water use efficiency and tissue water relations of the xylem-tapping root hemi-parasite Santalum album in pot culture with various N2-fixing woody hosts, a non-fixing host (a eucalypt), or in the absence of a host. Foliar N concentrations of Santalum were significantly greater than corresponding hosts and higher when on N2-fixing hosts than on the eucalypt, or without a host. Strong positive relationships were evident in Santalum between foliar N concentration, rates of net photosynthesis and instantaneous water use efficiencies. Photosynthesis rate and water use efficiency of Santalum were generally lower than in corresponding hosts, but transpiration rates were not noticeably different between associations. δ13C values of total shoot dry matter of Santalum were poorly correlated with instantaneous water use efficiency as measured by gas exchange, but associations involving the three legumes showed less negative δ13C values and better water use efficiencies for hosts, than corresponding parasites. Interpretation Of such differences was difficult in view of an earlier demonstration of substantial heterotrophic gain of C from certain hosts. Diurnal profiles of gas exchange and leaf water potential of hosts and parasites indicated closely coordinated diurnal stomatal responses of the parasite water relations to its host, thus resulting in transpiration rates of the parasite generating leaf water potential gradients favouring continuous abstraction of water and nutrients from a host. Tissue water relations of Santalum generally resembled those of water-stress tolerant species. Host-specific effects on relative water content and osmotic adjustment were slight and rated unimportant in regulation of water flow to the parasite, or in protecting it from temporary water stress in a host.
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xylem transfer of organic solutes in Santalum album l indian sandalwood in association with legume and non legume hosts
Annals of Botany, 1998Co-Authors: Andrew M. Radomiljac, John S. Pate, Kushan U Tennakoon, J A MccombAbstract:Indian sandalwood (Santalum album), a commercially important root hemi-parasitic angiosperm, was partnered singly in pot culture with one of three nitrogen-fixing legumes or a eucalypt host. Xylem (tracheal) sap of stems of host and parasite and ethanolic extracts of endophytic tissue of haustoria of the parasite were analysed for amino acids, organic acids and sugars to determine which sets of solutes were available to and obtained by the parasite from different hosts. There were high concentrations of asparagine, followed by glutamate, aspartate and γ-amino butyrate in the xylem sap solutes of the three legume hosts (Sesbania formosa, Acacia trachycarpa and A. ampliceps) and much higher levels of glutamate, aspartate, glutamine and arginine in the non-legume, Eucalyptus camaldulensis. Close resemblances between Santalum and legume hosts in concentration and composition of xylem sap amino acids, and in the amino acid spectra of the corresponding parasite endophytic tissue, indicated substantial direct intake of xylem N by Santalum from these hosts. By contrast, low N levels in xylem sap of E. camaldulensis and dissimilarities between its amino acid composition and that of partnered Santalum indicated that the parasite obtained little N from the xylem sap of this host. Xylem sap of hosts contained variable amounts of sucrose. glucose and fructose, whereas that of matching parasites was dominated by fructose. Dissimilarities were also evident in the proportional amounts of xylem-borne organic acids between hosts and parasite particularly for the eucalypt: Santalum partnership. Leaf extracts of the host: parasite pairings generally showed substantial differences in sugar and organic acid balance between partner species. Similarly, where amino acid spectra of host and parasite xylem sap and corresponding haustorial endophytes were closely similar, respective leaf compositions were markedly dissimilar. This implied that substantial metabolic patterns of incoming xylem solutes were highly idiosyncratic of the species in question. Data are related to previous information showing superior growth performance and higher photosynthetic rates and foliar N concentrations in Santalum partnered with the three legumes than with the eucalypt.
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Santalum album L. plantations: a complex interaction between parasite and host
1998Co-Authors: Andrew M. RadomiljacAbstract:This thesis examines a broad spectrum of physiological and silvicultural features of the highly valued woody angiosperm hemi-parasite Santalurn album L. (Indian sandalwood) in relation to its culture in plantations in northern Western Australia. Topics covered include allometry of host and Santalum when grown as single plant pairings in both field and pot culture, nutritional interactions between Santalum and beneficial and non-beneficial hosts, deleterious influences of parasitism on plantation productivity and heartwood induction in young trees. In Western Australia sandalwood is grown in the nursery for 8 months before establishment in the field and during this time a pot host is introduced. Survival of Santalurn after field establishment and its subsequent growth were significantly affected by the time of introduction of the pot host, Alternanthera nana. Increasing the period of the Santalum : Alternanthera association in the nursery to 109 days prior to field establishment markedly increased early growth of Salztalum plantations. Introduction at 134 days prior to field establishment was detrimental to the parasite as the Alternanthera was too vigorous for the small Santalum seedlings. Santalurn plants had a lower root : shoot ratio lower when cultured with Alternanthera in the nursery prior to field establishment compared with seedlings grown without Alternanthera. Alterrzantlzera survival in the field was high when it had been grown with Santalum for 12 weeks or more in the nursery prior to field establishment. After 1 1 weeks in the field a strong negative linear relationship was shown between Santalunz root : shoot ratio and Alternarzthera dry weight, and a positive linear relationship between Salztalum DW and Alternanthera DW. In Western Australia Santalu~n is established in the field with an intermediate host which nourishes the parasite for 3-5 years before Santalum becomes dependent on its long-term host and the intermediate host dies. The relationship between Santalum and several species tested as intermediate hosts was examined by pairing Santalum seedlings with intermediate host seedlings in 25 litre pots over a 10 month period. Growth of Santalum in pot culture with three N2-fixing woody intermediate hosts (Sesbania forrnosa, Acacia traclzycarpa and A. ampliceps), the woody non N2-fixing Eucalyptus camaldulensis or without a host varied considerably between host treatments. Santalum growth was greater and root : shoot ratio lower for seedlings grown with N2-fixing hosts compared with seedlings grown with E. carnaldulensis or with no host. The root : shoot ratio of unattached Santalum increased exponentially over time, whereas for all other treatments it remained relatively constant. An assessment of the value of the hosts, termed host use efficiency, was computed as Santalum shoot DW / host shoot DW. The host use efficiency of A. trachycalpa was greater than that of the other hosts. The xylem sap of hosts and Sarztalum, and ethanolic extracts of endophytic tissue of haustoria of Santalzkm were analysed for amino acids, organic acids and sugars to determine which solutes were available in the host and which were extracted by the Santalum haustoria from different hosts. There were similarities between Santalum and legume hosts in concentration and composition of xylem sap amino acids, and in the amino acid spectra of the corresponding Santalum endophytic tissue, whereas there were low N levels in xylem sap of E. camaldulensis and dissimilarities between its amino acid composition and that of Santalum. This indicated substantial direct intake of xylem N by Santalum from legume hosts but little N from the xylem sap of E. canzaldulensis. There were high concentrations of asparagine, glutamate, aspartate and y-amino glutamate in the xylem sap of the legume hosts, while in the non-legume the most common amino acids were glutamate, aspartate, glutamine and arginine. Proline, the predominant amino acid in the xylem sap of Santalum acurninatum growing in natural vegetation (Tennakoon et al. 1997) was not detected or present in very low concentrations in Santalurn album under these conditions. in the non-legume. Xylem sap of hosts contained variable amounts of sugars (sucrose, glucose and fructose) and organic acids (fumaric, citric and malic acid), whereas that of the parasitic Santalum was dominated by fructose and malic acid. Dissimilarities in the proportional amounts of xylem-borne sugars and organic acids were particularly evident for the E. camaldulensis : Santalum partnership. Diurnal profiles of photosynthesis and transpiration of Santalum were closely similar to those for corresponding hosts, whereas the midday leaf water potential of Santalum was consistently more negative than that of corresponding hosts. Net photosynthesis and water use efficiency was lower, but transpiration rates were similar to that of corresponding hosts. Nitrogen concentrations of foliage of Santalum were higher than their hosts, and higher when on legume hosts than on E. camaldulensis, or without a host. Nitrogen concentrations of Santalum foliage was strongly correlated with net photosynthesis and water use efficiency of Santalum. 813C values of shoot dry matter of Santalum were poorly correlated with instantaneous water use efficiency of Santalum. Tissue water relations of Santalum were similar to that of water-stress tolerant species. S. formosa proved the best host followed by Acacia ampliceps and A. traclzycarpa based on dry matter gains of Santalum. Estimates of heterotrophic gain of C of Santalum when grown in association with the legume hosts over a nine week period indicate 57.9% of C was derived from A. ampliceps, 45.5% from A. trachycarpa and 34.6% fiom S. fomosa. Abundance of haustorial attachments on roots of hosts was poorly correlated to Santalum shoot DW. Root nodules of legume hosts were parasitised by a small proportion of Santalum haustoria. Sodium and phosphorus concentrations of foliage of Santalum were generally higher than that of corresponding hosts. Net gains of calcium, potassium, phosphorus and sodium in Santalum was greatest when grown in association with hosts richest in the corresponding element. Net losses or only small gains of calcium, potassium, phosphorus and sodium were recorded when Santalum was grown with E. camaldulensis or without a host suggesting that Santalum has limited ability for uptake of those minerals through its own root system. To understand the effect of hosts on the productivity of a Santalum plantation a young plantation of Santalum with three host species Cathormion umbellatum, Sesbania formosa and Acacia anuera was selected to study the relationship between host quality and distance of hosts from Santalunz on Santalum health. The selected plantation showed marked decline in health and vigour of both Santalum and hosts between years 3 and 5. Parameters of the host plants were assessed to select the best predictor of Santalunz crown health. The height and diameter growth increment of Santalum between years 3 and 5 was strongly correlated to Santalum crown health. Santaluin crown health and growth increased as host quality increased, and the distance of host fiom Santalum decreased. An index, which combined host quality and the distance of the host from that of Santalum, was a better predictor of Santalum crown health than host distance or quality alone. The age at which heartwood is initiated in Santalum album under plantation conditions in Western Australia in unknown, but in natural stands in India it occurs between 10-13 years of age (Rai 1990). A field experiment was conducted to determine the efficacy of stem injections of paraquat andlor ethrel in initiating heartwood formation in five year old Santalum trees in a plantation. Trees injected with paraquat alone had a significantly greater extension of induced heartwood, both radially and vertically, than those trees injected with ethrel alone or distilled water. Eight months after treatment with paraquat or ethrel or a combination of these chemicals induced heartwood was formed, which had high lipid, and low starch and polysaccharide concentrations compared to the sapwood. Induced heartwood from both chemical treatments and their combinations contained total volatile oil and santalol oil (alpha and beta santalol) concentrations that were equal to or greater than that of naturally formed heartwood and greater than that of sapwood. Moisture content, and concentrations of K and Mg, and in some treatments Ca of induced heartwood were significantly lower than that of sapwood. The thesis concludes with a synthesis of the findings and suggestions for future research, with special reference to mid-rotation aspects of Santaltrm plantation silviculture.
Danica T Harbaugh - One of the best experts on this subject based on the ideXlab platform.
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polyploid and hybrid origins of pacific island sandalwoods Santalum santalaceae inferred from low copy nuclear and flow cytometry data
International Journal of Plant Sciences, 2008Co-Authors: Danica T HarbaughAbstract:It has been argued that polyploids are better adapted than diploids for long‐distance dispersal to and establishment on oceanic islands. To address this issue in a molecular phylogenetic framework, the extensive history of auto‐ and allopolyploidization in Santalum (Santalaceae), the sandalwood genus, was studied by sequencing the low‐copy nuclear gene waxy and investigating the ploidy level of all 16 species. Ploidy level was estimated by measuring the C value (total amount of DNA per nucleus) using flow cytometry and calibrating it by known chromosome numbers and new root‐tip chromosome counts of several taxa. Results indicate four ploidy levels in Santalum: diploid (n=10), tetraploid (n=20), hexaploid (n=30), and octoploid (n=40). The waxy phylogeny suggests that at least six independent polyploid events occurred in the history of Santalum: two allopolyploid events between distantly related species and four putatively autopolyploid events. An additional hybrid event between two tetraploid Hawaiian clad...
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Polyploid and Hybrid Origins of Pacific Island Sandalwoods (Santalum, Santalaceae) Inferred from Low‐Copy Nuclear and Flow Cytometry Data
International Journal of Plant Sciences, 2008Co-Authors: Danica T HarbaughAbstract:It has been argued that polyploids are better adapted than diploids for long‐distance dispersal to and establishment on oceanic islands. To address this issue in a molecular phylogenetic framework, the extensive history of auto‐ and allopolyploidization in Santalum (Santalaceae), the sandalwood genus, was studied by sequencing the low‐copy nuclear gene waxy and investigating the ploidy level of all 16 species. Ploidy level was estimated by measuring the C value (total amount of DNA per nucleus) using flow cytometry and calibrating it by known chromosome numbers and new root‐tip chromosome counts of several taxa. Results indicate four ploidy levels in Santalum: diploid (n=10), tetraploid (n=20), hexaploid (n=30), and octoploid (n=40). The waxy phylogeny suggests that at least six independent polyploid events occurred in the history of Santalum: two allopolyploid events between distantly related species and four putatively autopolyploid events. An additional hybrid event between two tetraploid Hawaiian clad...
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phylogeny and biogeography of the sandalwoods Santalum santalaceae repeated dispersals throughout the pacific
American Journal of Botany, 2007Co-Authors: Danica T Harbaugh, Bruce G BaldwinAbstract:: Results of the first genus-wide phylogenetic analysis for Santalum (Santalaceae), using a combination of 18S-26S nuclear ribosomal (ITS, ETS) and chloroplast (3' trnK intron) DNA sequences, provide new perspectives on relationships and biogeographic patterns among the widespread and economically important sandalwoods. Congruent trees based on maximum parsimony, maximum likelihood, and Bayesian methods support an origin of Santalum in Australia and at least five putatively bird-mediated, long-distance dispersal events out of Australia, with two colonizations of Melanesia, two of the Hawaiian Islands, and one of the Juan Fernandez Islands. The phylogenetic data also provide the best available evidence for plant dispersal out of the Hawaiian Islands to the Bonin Islands and eastern Polynesia. Inability to reject rate constancy of Santalum ITS evolution and use of fossil-based calibrations yielded estimates for timing of speciation and colonization events in the Pacific, with dates of 1.0-1.5 million yr ago (Ma) and 0.4-0.6 Ma for onset of diversification of the two Hawaiian lineages. The results indicate that the previously recognized sections Polynesica, Santalum, and Solenantha, the widespread Australian species S. lanceolatum, and the Hawaiian species S. freycinetianum are not monophyletic and need taxonomic revision, which is currently being pursued.
Tony Page - One of the best experts on this subject based on the ideXlab platform.
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domestication of northern sandalwood Santalum lanceolatum santalaceae for indigenous forestry on the cape york peninsula
Australian Forestry, 2019Co-Authors: A J Burridge, Tony Page, J R Huth, N ThompsonAbstract:ABSTRACTOver recent decades there has been considerable private investment in developing a sandalwood (Santalum spp.) industry due to the high international demand for products derived from its heartwood. While Santalum album (Indian sandalwood) has been the primary species used in these investments, other species may also have potential for commercialisation. In Cape York Peninsula (CYP), where Santalum lanceolatum occurs naturally, there are limited options for industry development, but research has shown that sandalwood products may provide an opportunity. The potential to incorporate sandalwood into existing Indigenous land management plans and further extend this into commercial plantings provides the opportunity to utilise an endemic tree species for economic development. This paper summarises participatory research with two Indigenous communities in the CYP to evaluate and improve conservation and development outcomes through sandalwood domestication.The project has been implemented through a serie...
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isolation and characterization of microsatellite loci in Santalum lanceolatum and Santalum leptocladum santalaceae
American Journal of Botany, 2010Co-Authors: Brendan L Jones, Michelle Waycott, Heather Robson, Ainsley Calladine, Tony PageAbstract:Santalum , or sandalwood, are hemiparasitic trees, with many species highly valued for their heartwood oils, resulting in widespread exploitation of the genus in the wild. One species has been recently classed as extinct, and of the remaining 15, one classed as endangered and two as vulnerable (IUCN, 2010). The detrimental impacts of harvesting being observed among many of the remaining unlisted species. Northern sandalwood, S. lanceolatum (R.Br.), is a wide-spread Australian species harvested for oil since the 1800s. Recently, S. lanceolatum sensu lato was revised taxonomically and a southern segregate species, S. leptocladum , defi ned ( Harbaugh, 2007 ). Here we report on the development of fi ve novel microsatellite loci for use in S. lanceolatum and S. leptocladum and the characterization of three microsatellite loci designed for S. insulare ( Lhuillier et al., 2006 ) and S. austrocaledonicum ( Bottin et al., 2005 ) for use in S. lanceolatum and S. leptocladum.
