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Margaret Heslewood

Molecular Systematist, Botany
Email
Margaret.Heslewood@rbgsyd.nsw.gov.au
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Research Interests

My interests lie broadly in using molecular data from nuclear and organelle genomes to investigate evolutionary relationships of primarily Australian plant, insect, bird, and animal groups.
 
My recent research has focussed on the molecular systematics of various higher plant families (e.g. Myrtaceae, Rutaceae), the fungal order Agaricales and the Hepatic families Fossombroniaceae and Lepidoziaceae as well as investigations of population genetics and phylogeography within the Cunoniaceae.

Current Projects

A Next Generation Sequencing (NGS) approach to investigate paralogy in Xanthostemon (Myrtaceae). 
Hermon Slade Foundation partly-sponsored project with Dr PG Wilson resolving generic limits in tribe Xanthostemoneae (Myrtaceae).
 
Xanthostemoneae is a group of tropical trees that often have spectacular flowers, with some species popular in cultivation. Morphology suggests that the genera in the tribe are poorly defined & could include unrecognised segregate taxa. Initial attempts to resolve taxonomic relationships in the Xanthostemoneae using traditional DNA sequencing approaches have been hampered by paralogy due to a duplication of a portion of the chloroplast (CP) genome in many Australian Xanthostemon species. This revised genomic approach to the problem will ensure only homologous sequences are used to construct phylogenies providing a more accurate and informative estimate of relationships in the tribe.
 
Advances in taxonomic relationships within Australian Acronychia (Rutaceae)
ABRS Bush Blitz funded research with Andrew Ford (CSIRO Land and Water, Atherton, QLD).
 
We aim to resolve taxonomic limits amongst all Australian Acronychia species and determine the affinities of an undescribed taxon discovered in the Australian Wet Tropics, unique in a range of morphological characters, which may represent a new species and for which the single known population is within a coastal lowland area of the Wet Tropics, a landscape which is highly fragmented due to development and agriculture. Datasets incorporating both morphological characters and molecular sequences from 5 loci are being used to investigate relationships within the genus and identify the affinities of the new taxon.
 
Resolution of taxonomic limits in Haloragis serra and the Haloragis exalata species complex. 
ABRS Bush Blitz funded research with Dr PG Wilson.
 
Within the family Haloragaceae, the Haloragis exalata species complex failed to resolve from accessions of H. serra in preliminary molecular analyses which included limited samples. The former species includes two infraspecific taxa listed as vulnerable at state and federal levels and resolution of taxonomic boundaries in the two species may impact conservation strategies for these taxa. Our project increased sampling of these species complexes from across their ranges in eastern Australia, creating a 5 gene dataset in an attempt to better resolve relationships, but as yet we have failed to resolve monophyletic species groups for several taxa. This study raises questions about the distinction between H. serra and H. exalata, which is primarily based on carpel number, with H. serra having only 2 carpels. One possibility is that reduction from the 4 carpellate condition has occurred multiple times and that this is an unreliable distinguishing feature.
 
Systematic studies in Rutaceae
Hermon Slade Foundation partially funded funded research with Marco Duretto to investigate taxonomic relationships within the Australasian Rutaceae, with a focus on the Boronia and Phebalium groups of genera.

Publication highlights

For a complete publication list, see my Google Scholar or ResearchGate profiles.

  1. Duretto MF, Heslewood MM, Bayly MJ (2020) Boronia (Rutaceae) is polyphyletic: Reinstating Cyanothamnus and the problems associated with inappropriately defined outgroups. Taxon 69(3): 481-499.
  2. Rye BL, Wilson PG, Heslewood MM, Perkins AJ, Thiele KR (2020) A new subtribal classification of Myrtaceae tribe Chamelaucieae. Australian Systematic Botany 33(2): 191-206.
  3. Wilson PG, Heslewood MM (2016) Phylogenetic position of Meteoromyrtus (Myrtaceae). Telopea 19: 47–57.
  4. Patzak SDF, Renner MAM, Schäfer-Verwimp A, Feldberg K, Heslewood MM, Peralta DF, Scneider H, Heinrichs J (2016) A phylogeny of Lophocoleaceae-Plagiochilaceae-Brevianthaceae and a revised classification of Plagiochilaceae. Organisms, Diversity and Evolution 16:481–495.
  5. Holzmeyer L, Duretto M, Crayn D, Hörandl E, Heslewood M, Jayanthan J, Appelhans MS (2015) Phylogeny of Acronychia (Rutaceae) and First Insights into its Historical Biogeography and the Evolution of Fruit Characters. PLOS One 10(8): e0136296. doi:10.1371/journal.pone.0136296.
  6. Heslewood MM, Lowe AJ, Crayn DM, Rossetto M (2014) Contrasting levels of connectivity and localised persistence characterise the latitudinal distribution of a wind-dispersed rainforest canopy tree. Genetica 142(3): 251-264.
  7. Johnson KA, Holland BR, Heslewood MM, Crayn DM (2012). Supermatrices, supertrees and serendipitous scaffolding: Inferring a well-resolved, genus-level phylogeny of Styphelioideae (Ericaceae) despite missing data. Molecular Phylogenetics & Evolution, 62(1): 146-158.
  8. Sommerville KD, Heslewood MM, Siemon JP, ad Offord CA (2009) Banking site soil for the germination of terrestrial orchid seed collections. Seed Science and Technology 37: 222-228.
  9. Heslewood MM, Brown EA (2007) A molecular phylogeny of the liverwort family Lepidoziaceae Limpr. in Australasia. Plant Systematics and Evolution 265: 193-219.
  10. Wilson PG, O’Brien MM, Heslewood MM, Quinn CJ (2005) Relationships within Myrtaceae sensu lato based on a matK phylogeny. Plant Systematics and Evolution 251: 3-19.