Research on Plantago

People: Heidi Meudt

The main aim of Te Papa's research on native New Zealand species of plantains (Plantago, Plantaginaceae) was to produce a taxonomic revision of all native New Zealand species of the genus. We also wanted to better understand the complex evolutionary history of the species, which likely involves genome doubling and hybridisation.

Te Papa research on New Zealand Myosotis focussed on the following questions:

• How are the New Zealand plantains related to one another and to their overseas relatives, especially the Australian species?

• How many native species of plantains are there, how can they be identified, where are they found, and what is their conservation status?

• What can genetic data tell us about the complex evolutionary and biogeographical history of the New Zealand species?

To address these questions, research specimens were collected and photographed in the field, and are now part of Te Papa’s collection and can be seen on Collections Online. These and other specimens were analysed genetically (both DNA sequences and AFLP DNA fingerprinting were used), cytogenetically, and morphologically.

Te Papa performed both independent and collaborative research on Plantago involving field, lab and herbarium studies. The results of Te Papa’s research on native Plantago are now published in the scientific literature, and are briefly outlined below.

Molecular phylogenetic and biogeographic studies were completed by Mei Lin Tay for her MSc thesis at Victoria University of Wellington (co-supervised by Te Papa Botany researcher Heidi Meudt, and Victoria University professors Phil Garnock-Jones and Peter Ritchie). Using DNA sequencing and molecular dating techniques, Mei Lin Tay’s MSc research showed that New Zealand species are closely related to Australian species, and colonised New Zealand at least three times in the last 2 million years or so. Additional sequencing of more samples allowed additional insights into the relationships among New Zealand species.

Chromosome counts of most native species were done in collaboration with Brian Murray (Auckland University). Chromosome numbers between 2n = 12 and 2n = 96 were documented, confirming previously published counts as well as finding new ones. This work strengthened the hypothesis that allopolyploidy (genome doubling followed by hybridisation) has shaped the evolution of New Zealand Plantago. Brian Murray and his former MSc student Charles Wong have taken this work further studying genome size and molecular cytogenetics.

Building upon these collaborative studies, Te Papa Botany researcher Heidi Meudt set out to find out how many native species of plantains there are, and how to distinguish them from one another. New analyses of DNA fingerprinting and morphological data were compared and integrated with data from all previous studies. This culminated in two additional publications, one examining the evolutionary history of the group, and one revising its taxonomy.

Eleven native species of native New Zealand Plantago are now recognised. They can be distinguished based on several morphological characters (e.g., seed number, seed shape, hairiness of scapes, bracts and sepals, and number of flowers and spikes). Novel taxonomic research findings include: recognising Plantago picta as a species (not a subspecies), showing that Plantago masoniae cannot be distinguished from Plantago triandra, and the description of a new native species, Plantago udicola.

Te Papa's research on Plantago is funded by Core funding for Crown Research Institutes from the Ministry of Business, Innovation and Employment’s Science and Innovation Group.

References

Meudt, Heidi M. 2012. New Zealand native Plantago taxonomy revised. Trilepidea 105: 4-5.

Meudt, Heidi M. 2012. Taxonomic revision of New Zealand endemic species of Plantago (Plantaginaceae). New Zealand Journal of Botany 50: 101-178.

Meudt, Heidi M. 2011. AFLP data reveal a history of auto- and allopolyploidy in New Zealand endemic species of Plantago (Plantaginaceae): New perspectives on a taxonomically-challenging group. International Journal of Plant Sciences 172: 220-237.

Murray, Brian, Heidi M. Meudt, Mei Lin Tay, and Phil Garnock-Jones. 2010. New chromosome numbers in New Zealand species of Plantago (Plantaginaceae). New Zealand Journal of Botany 48: 197-204.

Tay, Mei Lin, Heidi M. Meudt, Philip J. Garnock-Jones, Peter A. Ritchie 2010. DNA sequences from three genomes reveal multiple long-distance dispersals and non-monophyly of sections in Australasian Plantago (Plantaginaceae). Australian Systematic Botany 23: 47–68.

Tay, Mei Lin, Heidi M. Meudt, Phil Garnock-Jones, and Peter Ritchie. 2010. Testing species limits of New Zealand Plantago (Plantaginaceae) using internal transcribed spacer (ITS) DNA sequences. New Zealand Journal of Botany 48: 205-224.

Wong, Charles, and Brian G. Murray. 2014 In situ hybridization with genomic and rDNA probes reveals complex origins for polyploid New Zealand species of Plantago (Plantaginaceae). New Zealand Journal of Botany 52: 315-327.

Wong, Charles, and Brian G. Murray. 2012. Variable changes in genome size associated with different polyploid events in Plantago (Plantaginaceae): Genome size and polyploidy in Plantago. Journal of Heredity doi: 10.1093/jhered/ess049.