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Hartmut H. Hilger - One of the best experts on this subject based on the ideXlab platform.
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multiple origins for hound s tongues cynoglossum l and navel seeds omphalodes mill the phylogeny of the borage family Boraginaceae s str
Molecular Phylogenetics and Evolution, 2013Co-Authors: Maximilian Weigend, Federico Selvi, Federico Luebert, Grischa Brokamp, Hartmut H. HilgerAbstract:Abstract Recent studies all indicated that both the affinities and subdivision of Boraginaceae s.str. are unsatisfactorily resolved. Major open issues are the placement and affinities of Boraginaceae s.str. in Boraginales and the major clades of the family, with especially the large tribes Cynoglosseae and Eritrichieae repeatedly retrieved as non-monophyletic groups, and the doubtful monophyly of several larger genera, especially Cynoglossum and Omphalodes . The present study addresses and solves these questions using two plastid markers ( trnL – trnF , rps 16) on the basis of a sampling including 16 outgroup taxa and 172 ingroup species from 65 genera. The phylogeny shows high statistical support for most nodes on the backbone and on the individual clades. Boraginaceae s.str. are sister to African Wellstediaceae, Wellstediaceae–Boraginaceae s.str. is sister to African Codonaceae. Echiochileae are retrieved as sister to the remainder of Boraginaceae s.str., which, in turn, fall into two major clades, the Boragineae–Lithospermeae (in a well-supported sister relationship) and the Cynoglosseae s.l. (including Eritrichieae). Cynoglosseae s.l. is highly resolved, with Trichodesmeae (incl. Microcaryum , Lasiocaryum ) as sister to the remainder of the group. Eritrichieae s.str. ( Eritrichium , Hackelia , Lappula ) are resolved on a poorly supported polytomy together with the Omphalodes -clade (incl. Myosotidium , Cynoglossum p.p.), and the Mertensia -clade (incl. O. scorpioides , Asperugo ). The Myosotideae ( Myosotis , Trigonotis , Pseudomertensia ) are retrieved in a well-supported sister-relationship to the core-Cynoglosseae, the latter comprising all other genera sampled. Cynoglossum is retrieved as highly para- and polyphyletic, with a large range of generic segregates embedded in Cynoglossum , but other species of Cynoglossum are sister to Microula or to the American “Eritrichieae” ( Cryptantha and allied genera). Representatives of the genus Cynoglossum in its current definition are segregated onto six independent lineages, members of Omphalodes onto three independent lineages. At least 11 of the genera here sampled are deeply nested in other genera. The data show that individual details of nutlet morphology (e.g., winged margins, glochidia) are highly homoplasious. Conversely, a complex of nutlet characters (e.g., characters of the gynobase and cicatrix together with nutlet orientation and sculpturing) tends to circumscribe natural units. Geographical distribution of major clades suggests that the family originated in Africa and western Asia and radiated to eastern Eurasia, with several independent dispersal events into Australia and the New World.
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Multiple origins for Hound’s tongues (Cynoglossum L.) and Navel seeds (Omphalodes Mill.) – The phylogeny of the borage family (Boraginaceae s.str.)
Molecular Phylogenetics and Evolution, 2013Co-Authors: Maximilian Weigend, Federico Selvi, Federico Luebert, Grischa Brokamp, Hartmut H. HilgerAbstract:Abstract Recent studies all indicated that both the affinities and subdivision of Boraginaceae s.str. are unsatisfactorily resolved. Major open issues are the placement and affinities of Boraginaceae s.str. in Boraginales and the major clades of the family, with especially the large tribes Cynoglosseae and Eritrichieae repeatedly retrieved as non-monophyletic groups, and the doubtful monophyly of several larger genera, especially Cynoglossum and Omphalodes . The present study addresses and solves these questions using two plastid markers ( trnL – trnF , rps 16) on the basis of a sampling including 16 outgroup taxa and 172 ingroup species from 65 genera. The phylogeny shows high statistical support for most nodes on the backbone and on the individual clades. Boraginaceae s.str. are sister to African Wellstediaceae, Wellstediaceae–Boraginaceae s.str. is sister to African Codonaceae. Echiochileae are retrieved as sister to the remainder of Boraginaceae s.str., which, in turn, fall into two major clades, the Boragineae–Lithospermeae (in a well-supported sister relationship) and the Cynoglosseae s.l. (including Eritrichieae). Cynoglosseae s.l. is highly resolved, with Trichodesmeae (incl. Microcaryum , Lasiocaryum ) as sister to the remainder of the group. Eritrichieae s.str. ( Eritrichium , Hackelia , Lappula ) are resolved on a poorly supported polytomy together with the Omphalodes -clade (incl. Myosotidium , Cynoglossum p.p.), and the Mertensia -clade (incl. O. scorpioides , Asperugo ). The Myosotideae ( Myosotis , Trigonotis , Pseudomertensia ) are retrieved in a well-supported sister-relationship to the core-Cynoglosseae, the latter comprising all other genera sampled. Cynoglossum is retrieved as highly para- and polyphyletic, with a large range of generic segregates embedded in Cynoglossum , but other species of Cynoglossum are sister to Microula or to the American “Eritrichieae” ( Cryptantha and allied genera). Representatives of the genus Cynoglossum in its current definition are segregated onto six independent lineages, members of Omphalodes onto three independent lineages. At least 11 of the genera here sampled are deeply nested in other genera. The data show that individual details of nutlet morphology (e.g., winged margins, glochidia) are highly homoplasious. Conversely, a complex of nutlet characters (e.g., characters of the gynobase and cicatrix together with nutlet orientation and sculpturing) tends to circumscribe natural units. Geographical distribution of major clades suggests that the family originated in Africa and western Asia and radiated to eastern Eurasia, with several independent dispersal events into Australia and the New World.
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Fossil and extant Western Hemisphere Boragineae, and the polyphyly of "Trigonotideae" Riedl (Boraginaceae: Boraginoideae)
Systematic Botany, 2010Co-Authors: Maximilian Weigend, Marc Gottschling, Federico Selvi, Hartmut H. HilgerAbstract:Abstract Boraginaceae tribe Trigonotideae comprises a heterogenous assemblage of taxa, many of which have been shown to belong to widely divergent lineages in Boraginaceae in the recent past, with some taxa now assigned to three of the four currently recognized tribes of the Boraginaceae s. s., namely the Cynoglosseae, Echiochileae, and Lithospermeae. The systematics of Moritzia and Thaumatocaryon, the only endemic South American genera of Boraginaceae, have been controversially discussed in the past, and their most recent placement was in Trigonotideae. The present study investigates the phylogenetic relationships of “Trigonotideae” based on micromorphology and molecular data (ITS including 5.8S rRNA, and the trnL-trnF spacer). Molecular data show that “Trigonotideae” are polyphyletic, and none of its members is at all closely related to Trigonotis itself. Moritzia and Thaumatocaryon are closely allied to each other and are the sister group of the Old World Boragineae. Flowers, pollen, and fruit morpholo...
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The Euro+Med treatment of Boraginaceae in Willdenowia 34 - a response
Willdenowia, 2005Co-Authors: Hartmut H. Hilger, Marc Gottschling, Federico Selvi, Massimo Bigazzi, Elisabeth Långström, Elke Zippel, Nadja Diane, Maximilian WeigendAbstract:Abstracts Hilger, H. H., Gottschling, M., Selvi, F., Bigazzi, M., Langstrom, E., Zippel, E., Diane, N. & Weigend, M.: The Euro+Med treatment of Boraginaceae in Willdenowia 34 — a response. — Willdenowia 35: 43–48. — ISSN 0511-9618; © 2005 BGBM Berlin-Dahlem. doi:10.3372/wi.35.35101 (available via http://dx.doi.org/) The classification of B. Valdes proposed in Willdenowia 34 in 2004 is shown to be for practical purposes incomplete, incorrect, inconsistent and out of date. A revised list of genera and tribes of Boraginales (Boraginaceae s.l.) occurring in the region based on recent data is presented.
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Boraginaceae cymes are exclusively scorpioid and not helicoid
Taxon, 2003Co-Authors: M.h. Buys, Hartmut H. HilgerAbstract:Boraginaceae have erroneously been associated with helicoid cymes, when upon closer inspection they exclusively possess scorpioid cymes (cincinni). A discussion of the inflorescence structure in Boraginaceae is presented with the help of an overview of monochasial branching systems and a three-dimensional representation thereof. Reasons for the incorrect description of Boraginaceae inflorescences are also provided.
James I. Cohen - One of the best experts on this subject based on the ideXlab platform.
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Adelinia and Andersonglossum (Boraginaceae), Two New Genera from New World Species of Cynoglossum
Systematic Botany, 2015Co-Authors: James I. CohenAbstract:Abstract Recent phylogenetic evidence suggests that Cynoglossum (Boraginaceae), a cosmopolitan genus, is not monophyletic, but relationships among members of the genus remain uncertain. This is particularly the case for North American species of Cynoglossum. Utilizing DNA sequence data, a phylogeny has been reconstructed to investigate the evolutionary relationships among the New and Old World species of Cynoglossum and other members of Boraginaceae. The resulting phylogeny resolved that North American species of Cynoglossum are members of a clade distinct from the Old World species, and these North American species belong to two distinct lineages. Cynoglossum occidentale and C. virginianum are sister species, and C. grande is a member of a separate group. Given these evolutionary relationships in conjunction with diagnostic morphological features, two new genera are proposed for these species, Andersonglossum and Adelinia, with four name transfers: Andersonglossum boreale, Andersonglossum occidentale, An...
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A phylogenetic analysis of morphological and molecular characters of Boraginaceae: evolutionary relationships, taxonomy, and patterns of character evolution
Cladistics, 2013Co-Authors: James I. CohenAbstract:The angiosperm family Boraginaceae includes ca. 1600 species distributed among ca. 110 genera. Some floral features are constant within the family, but many vegetative, floral, pollen, and nutlet traits vary. Utilizing 224 species of Boraginaceae and related taxa, five matrices were constructed with various combinations of morphological characters, three chloroplast DNA regions, and one nuclear ribosomal DNA region. Phylogenetic analyses were conducted for these matrices, and patterns of character evolution were examined. Boraginaceae is resolved as monophyletic, with Wellstedia as its sister. Codon is sister to Boraginaceae + Wellstedia. Although most of the investigated morphological characters have a low consistency index, particular character states are synapomorphies for large clades in each of the tribes of the family. In Boraginaceae, the breeding system heterostyly evolved at least 12 times, which is the largest number of origins resolved in any family; therefore Boraginaceae can serve as a model for the evolution and development of heterostyly. Nutlet ornamentation is most diverse in Cynoglosseae and Trichodesmeae, while pollen and floral features are most variable in Boragineae and Lithospermeae. Phylogenetic relationships and patterns of character evolution identified in the present study set the stage for future work creating an updated taxonomic system of Boraginaceae. © The Willi Hennig Society 2013.
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Molecular Phylogenetics, Molecular Evolution, and Patterns of Clade Support in Lithospermum (Boraginaceae) and Related Taxa
Systematic Botany, 2012Co-Authors: James I. Cohen, Jerrold I. DavisAbstract:Abstract Utilizing 10 cpDNA regions and thorough taxon sampling, a phylogeny is reconstructed for Lithospermum and related members of both Lithospermeae, the tribe to which it is assigned, and Boraginaceae. Lithospermum is supported as monophyletic, and the genus is hypothesized to have originated in the Old World, after which there was one colonization of the New World. The heterostylous breeding system is inferred to have originated within Lithospermum either seven times or six times with one loss, and with other independent origins within Lithospermeae. The stability of the 10-region matrix is investigated, as are the number and combination of regions necessary to accurately reconstruct phylogenies. The combination of concatenated regions is important, and the following regions are recommended for future phylogenetic studies of genera of Boraginaceae: the rpl16 intron, matK, psbA-trnH, trnL-rpl32, and trnQ-rps16. The use of these recommended regions is conservative, and it contrasts with most intragene...
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a phylogenetic analysis of morphological and molecular characters of lithospermum l Boraginaceae and related taxa evolutionary relationships and character evolution
Cladistics, 2011Co-Authors: James I. CohenAbstract:Lithospermum (Boraginaceae) includes ca. 60 species and exhibits a wide range of floral, palynological, and vegetative diversity. Phylogenetic analyses based on 10 chloroplast DNA regions and 22 morphological characters were conducted in order to (i) examine evolutionary relationships within Lithospermum and among related genera of Boraginaceae, and (ii) investigate patterns of morphological evolution. Several morphological features, such as long-funnelform corollas, faucal appendages, reciprocal herkogamy, and evident secondary leaf venation, have evolved multiple times within the genus. In contrast, other morphological features, including the presence of glands and the position and number of pollen pores, are less plastic and tend to characterize larger clades. Some features, including the presence of glands, are interpreted as symplesiomorphic for Lithospermum, while others, such as evident secondary leaf venation, appear to have originated repeatedly. The range of structural diversity that occurs among the species of Lithospermum suggests the potential utility of this genus as a model for integrative studies of evolution, development, and molecular biology.© The Willi Hennig Society 2011.
Maximilian Weigend - One of the best experts on this subject based on the ideXlab platform.
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Towards an integrative understanding of stamen–corolla tube modifications and floral architecture in Boraginaceae s.s. (Boraginales)
Botanical Journal of the Linnean Society, 2020Co-Authors: Julius Jeiter, Stella Langecker, Maximilian WeigendAbstract:Abstract Morphological studies rarely address floral organ modifications or their integration into floral architecture and floral function. Boraginaceae show two prominent types of stamen–corolla tube modifications: faucal and basal scales. Both types, especially faucal scales, are widely used in classification. Here, the ontogeny and morphology of faucal and basal scales are studied in 29 species from eight tribes and all three subfamilies of Boraginaceae s.s. (=Boraginoideae sensu APG IV) using scanning electron microscopy. Integration into floral architecture is visualized with micro-computed tomography (µCT). Faucal and basal scales are present in 18 and 27 species, respectively. Both types of scales develop late in flower ontogeny, but with variable timing. Faucal scales are morphologically far more variable than basal scales. Faucal scales are located close to the anthers and sometimes are involved in anther cone formation. Basal scales cover either the gynoecial disc nectary or the entire ovary. The different scale morphologies identified here enclose complex internal spaces, but they show no obvious phylogenetic patterns. This probably indicates strong functional constraints and adaptive pressures. This is a first in-depth study of the morphology and development of stamen–corolla tube modifications in Boraginaceae s.s., demonstrating that in situ three-dimensional visualization of floral architecture with µCT provides unprecedented insights into the evolution and functional integration of stamen–corolla tube modifications in Boraginales.
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Biogeographic Events Are Not Correlated with Diaspore Dispersal Modes in Boraginaceae
Frontiers in Ecology and Evolution, 2017Co-Authors: Juliana Chacón, Federico Luebert, Maximilian WeigendAbstract:Long-distance dispersal seems to be the main biogeographic event responsible for intriguing distribution patterns in plant groups in which sister taxa are separated by thousands of kilometers of distance across oceans and continents. The biotic and abiotic mechanisms behind such dispersal events are poorly understood and many attempts have been made to explain how plants can manage to disperse and survive these long journeys. The biogeographic history of Boraginaceae, a subcosmopolitan plant family with many disjunct clades, is here addressed and analyzed in the context of the different dispersal modes exhibited by the species. The lack of a clear pattern between the main dispersal events in Boraginaceae and the phylogenetic distribution of the dispersal modes indicates that no single dispersal mechanism can be associated with the events of dispersal in the family. Moreover, adaptations to different dispersal agents and unassisted dispersal modes in some clades might have promoted the diversification of Boraginaceae in various habitats across several continents. Our study reveals that long-distance dispersal is a very complex process that needs to be analyzed in the context of climatic and environmental changes and the response of plants and their dispersal vectors to these variable conditions.
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Fossil nutlets of Boraginaceae from the continental Eocene of Hamada of Méridja (southwestern Algeria): The first fossil of the Borage family in Africa
American Journal of Botany, 2015Co-Authors: Sid Ahmed Hammouda, Maximilian Weigend, Fateh Mebrouk, Juliana Chacón, Mustapha Bensalah, Hans-jürgen Ensikat, Mohammed AdaciAbstract:2 PREMISE OF THE STUDY: The Paleogene deposits of the Hamada of Meridja, southwestern Algeria, are currently dated as lower-to-middle Eocene in age based on fossil gastropods and charophytes. Here we report the presence of fruits that can be assigned to the Boraginaceae s.str., apparently representing the fifossil record for this family in Africa, shedding new light on the historical biogeography of this group. METHODS: Microscopic studies of the fossil nutlets were carried out and compared to extant Boraginaceae nutlets, and to types reported in the literature for this family. KEY RESULTS: The fossils are strikingly similar in general size and morphology, particularly in the fi ner details of the attachment scar and ornamentation, to nutlets of extant representatives of the Boraginaceae tribe Echiochileae, and especially the genus Ogastemma . We believe that these nutlets represent an extinct member of this lineage. CONCLUSIONS: The Ogastemma -like fossils indicate that the Echiochileae, which are most diverse in northern Africa and southwestern Asia, have a long history in this region, dating back to the Eocene. This tribe corresponds to the basal-most clade in Boraginaceae s.str., and the fossils described here agree well with an assumed African origin of the family and the Boraginales I, providing an important additional calibration point for dating the phylogenies of this clade.
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multiple origins for hound s tongues cynoglossum l and navel seeds omphalodes mill the phylogeny of the borage family Boraginaceae s str
Molecular Phylogenetics and Evolution, 2013Co-Authors: Maximilian Weigend, Federico Selvi, Federico Luebert, Grischa Brokamp, Hartmut H. HilgerAbstract:Abstract Recent studies all indicated that both the affinities and subdivision of Boraginaceae s.str. are unsatisfactorily resolved. Major open issues are the placement and affinities of Boraginaceae s.str. in Boraginales and the major clades of the family, with especially the large tribes Cynoglosseae and Eritrichieae repeatedly retrieved as non-monophyletic groups, and the doubtful monophyly of several larger genera, especially Cynoglossum and Omphalodes . The present study addresses and solves these questions using two plastid markers ( trnL – trnF , rps 16) on the basis of a sampling including 16 outgroup taxa and 172 ingroup species from 65 genera. The phylogeny shows high statistical support for most nodes on the backbone and on the individual clades. Boraginaceae s.str. are sister to African Wellstediaceae, Wellstediaceae–Boraginaceae s.str. is sister to African Codonaceae. Echiochileae are retrieved as sister to the remainder of Boraginaceae s.str., which, in turn, fall into two major clades, the Boragineae–Lithospermeae (in a well-supported sister relationship) and the Cynoglosseae s.l. (including Eritrichieae). Cynoglosseae s.l. is highly resolved, with Trichodesmeae (incl. Microcaryum , Lasiocaryum ) as sister to the remainder of the group. Eritrichieae s.str. ( Eritrichium , Hackelia , Lappula ) are resolved on a poorly supported polytomy together with the Omphalodes -clade (incl. Myosotidium , Cynoglossum p.p.), and the Mertensia -clade (incl. O. scorpioides , Asperugo ). The Myosotideae ( Myosotis , Trigonotis , Pseudomertensia ) are retrieved in a well-supported sister-relationship to the core-Cynoglosseae, the latter comprising all other genera sampled. Cynoglossum is retrieved as highly para- and polyphyletic, with a large range of generic segregates embedded in Cynoglossum , but other species of Cynoglossum are sister to Microula or to the American “Eritrichieae” ( Cryptantha and allied genera). Representatives of the genus Cynoglossum in its current definition are segregated onto six independent lineages, members of Omphalodes onto three independent lineages. At least 11 of the genera here sampled are deeply nested in other genera. The data show that individual details of nutlet morphology (e.g., winged margins, glochidia) are highly homoplasious. Conversely, a complex of nutlet characters (e.g., characters of the gynobase and cicatrix together with nutlet orientation and sculpturing) tends to circumscribe natural units. Geographical distribution of major clades suggests that the family originated in Africa and western Asia and radiated to eastern Eurasia, with several independent dispersal events into Australia and the New World.
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Multiple origins for Hound’s tongues (Cynoglossum L.) and Navel seeds (Omphalodes Mill.) – The phylogeny of the borage family (Boraginaceae s.str.)
Molecular Phylogenetics and Evolution, 2013Co-Authors: Maximilian Weigend, Federico Selvi, Federico Luebert, Grischa Brokamp, Hartmut H. HilgerAbstract:Abstract Recent studies all indicated that both the affinities and subdivision of Boraginaceae s.str. are unsatisfactorily resolved. Major open issues are the placement and affinities of Boraginaceae s.str. in Boraginales and the major clades of the family, with especially the large tribes Cynoglosseae and Eritrichieae repeatedly retrieved as non-monophyletic groups, and the doubtful monophyly of several larger genera, especially Cynoglossum and Omphalodes . The present study addresses and solves these questions using two plastid markers ( trnL – trnF , rps 16) on the basis of a sampling including 16 outgroup taxa and 172 ingroup species from 65 genera. The phylogeny shows high statistical support for most nodes on the backbone and on the individual clades. Boraginaceae s.str. are sister to African Wellstediaceae, Wellstediaceae–Boraginaceae s.str. is sister to African Codonaceae. Echiochileae are retrieved as sister to the remainder of Boraginaceae s.str., which, in turn, fall into two major clades, the Boragineae–Lithospermeae (in a well-supported sister relationship) and the Cynoglosseae s.l. (including Eritrichieae). Cynoglosseae s.l. is highly resolved, with Trichodesmeae (incl. Microcaryum , Lasiocaryum ) as sister to the remainder of the group. Eritrichieae s.str. ( Eritrichium , Hackelia , Lappula ) are resolved on a poorly supported polytomy together with the Omphalodes -clade (incl. Myosotidium , Cynoglossum p.p.), and the Mertensia -clade (incl. O. scorpioides , Asperugo ). The Myosotideae ( Myosotis , Trigonotis , Pseudomertensia ) are retrieved in a well-supported sister-relationship to the core-Cynoglosseae, the latter comprising all other genera sampled. Cynoglossum is retrieved as highly para- and polyphyletic, with a large range of generic segregates embedded in Cynoglossum , but other species of Cynoglossum are sister to Microula or to the American “Eritrichieae” ( Cryptantha and allied genera). Representatives of the genus Cynoglossum in its current definition are segregated onto six independent lineages, members of Omphalodes onto three independent lineages. At least 11 of the genera here sampled are deeply nested in other genera. The data show that individual details of nutlet morphology (e.g., winged margins, glochidia) are highly homoplasious. Conversely, a complex of nutlet characters (e.g., characters of the gynobase and cicatrix together with nutlet orientation and sculpturing) tends to circumscribe natural units. Geographical distribution of major clades suggests that the family originated in Africa and western Asia and radiated to eastern Eurasia, with several independent dispersal events into Australia and the New World.
R C Lewis - One of the best experts on this subject based on the ideXlab platform.
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host specificity of uromyces heliotropii a fungal agent for the biological control of common heliotrope heliotropium europaeum in australia
Annals of Applied Biology, 1992Co-Authors: S Hasan, E S Delfosse, Elisa Aracil, R C LewisAbstract:Summary Common heliotrope, Heliotropium europaeum (Boraginaceae), a summer annual, is a serious weed of pastures in Australia causing poisoning in sheep and other grazing animals. The weed is native to Mediterranean and Middle Eastern regions of Eurasia where it is attacked by several arthropods and pathogens including the rust fungus Uromyces heliotropii. The host-specificity of a virulent and effective strain of the rust from Turkey has been tested by inoculating 96 plants of importance to the Australasian region using both microscopic and macroscopic observations of the reaction of host and non-host plants. The test plants included several members of the Boraginaceae and related families as well as species of Heliotropium native to Australia. The infection was mostly limited to European species of Heliotropium. U. heliotropii was thus found to represent a safe introduction and has recently been introduced to Australia for the biological control of common heliotrope.
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Host‐specificity of Uromyces heliotropii, a fungal agent for the biological control of common heliotrope (Heliotropium europaeum) in Australia
Annals of Applied Biology, 1992Co-Authors: S Hasan, E S Delfosse, Elisa Aracil, R C LewisAbstract:Summary Common heliotrope, Heliotropium europaeum (Boraginaceae), a summer annual, is a serious weed of pastures in Australia causing poisoning in sheep and other grazing animals. The weed is native to Mediterranean and Middle Eastern regions of Eurasia where it is attacked by several arthropods and pathogens including the rust fungus Uromyces heliotropii. The host-specificity of a virulent and effective strain of the rust from Turkey has been tested by inoculating 96 plants of importance to the Australasian region using both microscopic and macroscopic observations of the reaction of host and non-host plants. The test plants included several members of the Boraginaceae and related families as well as species of Heliotropium native to Australia. The infection was mostly limited to European species of Heliotropium. U. heliotropii was thus found to represent a safe introduction and has recently been introduced to Australia for the biological control of common heliotrope.
Hassan S Ghaziaskar - One of the best experts on this subject based on the ideXlab platform.
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separation of γ linolenic and other polyunsaturated fatty acids from Boraginaceae via supercritical co2
IEEE Journal of Solid-state Circuits, 2011Co-Authors: S M Ghoreishi, E Mardani, Hassan S GhaziaskarAbstract:Essential fatty acids were extracted from Echium amoenum (Boraginaceae) seed oil via supercritical carbon dioxide and the results were compared with conventional Soxhlet method as the base case of 100% recovery. The response surface methodology was used to optimize the effective extraction parameters. The chemical composition of recovered oil was analyzed by polar and non-polar gas chromatograph-flame ionization detector columns. The experimental results indicated that echium seed contained 25 wt% oil and the maximum extraction oil recovery of 92% was obtained via supercritical CO2 at optimal operating conditions (43°C, 280 bar, 1.5 mL/min, 25 min static time and 130 min dynamic time). At similar operating conditions, applying 2.5 and 5 mol% ethanol as a modifier enhanced the recovery to 96 and 112%, respectively. The results showed that supercritical fluid extraction is a viable technique for separation of constituents such as γ-linolenic acid (7–8%), palmitic acid (6–7%), stearic acid (3–4%), oleic acid (12–13%), linoleic acid (19–20%), α-linolenic acid (40–41%) and stearidonic acid (8–9%) from Boraginaceae.
