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Phylogenetics of the grass family (poaceae)

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Phylogenetics of the grass family (poaceae)

  1. 1. PHYLOGENETICS OF THE GRASS FAMILY (POACEAE) Vishnu Mohanan Supervisor: Dr. Trevor Hodkinson
  2. 2. WHY GRASSES?  Biodiversity  Over 9000 species  Pioneer species and establishment of ecosystems  Economic  70% of all food crop  Fuel  Construction  Paper
  3. 3. WHY PHYLOGENETICS?  How the group is organised  Improved resolution when used in conjunction with geographical and morphological data.  Major diversification events  Eg: Emergence of woodiness in Bamboos  Resolution of taxonomic conflicts  Similar morphology, different group? Plantae Angiosperm Monocot Poales Poaceae
  4. 4. OUR STUDY  Sequence grass DNA  Huge species number  Generic level analysis  Asymmetry in phylogenies
  5. 5. METHOD PCR Cleanup Extraction and purification Electrophoresis gel Amplification of gene region using PCR Collection and Storage Cycle Sequencing Cycle Sequencing cleanup Fragment Analysis using Genetic Sequencer Electrophoresis gel Yes No
  6. 6. AGAROSE GEL ELECTROPHORESIS Total DNA
  7. 7. AGAROSE GEL ELECTROPHORESIS PCR Products
  8. 8. AGAROSE GEL ELECTROPHORESIS
  9. 9. ELECTROPHEROGRAM
  10. 10. SEQUENCES ATTAINED  18 sequences attained  12 Phylostachys species  2 Fargesia species  1 Pleoblastus species
  11. 11. ALIGNMENT  Aligned by eye in PAUP
  12. 12. PHYLOGENETIC TREE  Well resolved BEP clade  Bambuseae as a monophyletic tribe  Olyreae sister to Bambuseae  Pooideae sister to Bambusoideae BEP Clade Bambusoideae
  13. 13. BAMBUSEAE  Separation in geography  Temperate bamboos  Phylostachys  Fargesia  Pleoblastus  Paleotropical  Neotropical
  14. 14. COMPARING TREES BEP Clade Bambusoideae
  15. 15. DISCUSSION  Ancestral bamboo herbaceous or woody?  Woodiness has evolved independently number of times  According to the results, likely that ancestor herbaceous  Olyreae remained herbaceous  Bambuseae developed woodiness  Conflicts with published studies  Further sampling of Olyreae
  16. 16. DISCUSSION  Storage of plant material in liquid CTAB viable?  High degradation of DNA material  Hard to work with  Unreliable PCR amplification
  17. 17. ACKNOWLEDGEMENTS  Dr. Trevor Hodkinson  Postgraduates: Ruth, Muriel and Caoimhe  Trish!  Fellow ‘UREKA’ns  Dr. Daniel Kelly, Fiona Moloney and Dr. Martyn Linnie  Luke McNally, our fearless leader  Science Foundation Ireland
  18. 18. QUESTIONS?

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