System of study

The Senecio latus species complex

Ortiz-Barrientos et al (2011).001

The Senecio lautus species complex is a monophyletic group that consists of multiple ecotypes and taxonomic species, including S. pinnatifolius, S. brigalowensis, S. lacustrinus and close realtives from New Zealand. The complex belongs to a plant genus which comprises more than 1000 species worldwide, making it ideal for studies of speciation and adaptation. Members of the S. lautus complex are native to Australia and New Zealand and contains multiple ecotypes that show strong morphological (e.g. leaf and architecture and growth habit) correlations with different environments across the continent (click picture above). For instance, the coastal ecotypes are prostrate when inhabiting rocky headlands, but erect when they inhabit beach sand dunes. Genetically-based prostrate and erect forms are also found in the alpine regions of Victoria. Most ecotypes are short-lived perennials, and flower through out the year. Germination peak varies between ecotypes, but coastal ones enjoy the wet summers. Coastal ecotypes flower in under 8-10 weeks in glasshouse conditions, and senesce after 16-20 weeks. However, under field conditions, it may take upto 6-8 months to see their first flowers. The basal chromosome number for Australian Senecio is n=20, although there are relatives in Africa that have 10 chromosomes. Despite the ancestral genome duplication, large fractions of the genome, as well as many traits, segregate under mendelian law, suggesting that S. lautus is genetically diploid. We take advantage of these qualities to produce various genetic crossess and breeding designs that then we take into the field or into experimental soil plots at UQ. 

Our research group is part of the Senecio Research Network, led by Prof. Richard Abbott, which consists of at least 14 research groups from around the world. Many of these groups are building genomic resources for several species (www.seneciodb.org), therefore accelerating the speed of discovery on speciation and adaptation across flowering plants.  Our own lab has produced a deno vo assembly of S. lautus transcriptome, and a draft of the gene space. Other projects in our lab use RAD tags, most of which we can map onto our genomic scaffolds. 

© Daniel Ortiz Barrientos 2017