Abstract submitted to the International Grasslands Conference
Relationships between the New Zealand Triticeae
Alan V Stewart, Nick Ellison 1
PGG Seeds, PO Box 3100 , Christchurch 8015, New Zealand .
1 AgResearch, Private Bag 11008 Palmerston North, New Zealand .
Keywords: New Zealand , Elymus, Stenostachys
The New Zealand flora contains 3 genera within the Triticeae, Elymus, Australopryum and Stenostachys . ITS and cpDNA sequence analysis was carried out on members of the New Zealand Elymus and Stenostachys . The genomic constitution of the hexaploid Elymus has been previously determined as StYW , the Australopyrum as W and Elymus enysii as HW (Svitashev et al. 1998, Connor and Edgar 2000). To date the genomic constitution of the tetraploid Stenostachys and octoploid Elymus tenuis has been unclear.
ITS sequence showed two distinct clades. The first contained the hexaploid and octoploid Elymus species and the second contained the two tetraploids Stenostachys laevis and S. gracilis, diploid Australopyrum calcis and tetraploid Elymus enysii.
This is interpreted to mean that ITS majority sequence in the hexaploid and octoploid Elymus clade is the St or Y genome while the majority ITS sequence in the other Stenostachys, Australopyrum and E. enysii clade is the W genome. Genbank searches of species with closely aligning sequences of non-New Zealand species show that the closest sequence to New Zealand hexaploid Elymus are Elymus and Secale sp, and the closest to Elymus enysii are the Australian Australopyrum .
CpDNa sequence showed two distinct clades. The first containing the hexaploid and octoploid Elymus and Australopyrum calcis and the second the two Stenostachys and Elymus enysii .
The cpDNA result suggests that the maternal genome of the hexaploid and octoploid Elymus is the W genome of Australopyrum while the maternal genome of Stenostachys and Elymus enysii is the H genome. Genbank searches of species with closely aligning sequences of non-New Zealand species show that the closest sequence to New Zealand hexaploid Elymus is Elymus wawawaiensis of North America ; the closest to New Zealand Australopyrum calcis are the Australian Australopyrum species followed by Agropyrum mongolicum ; and the closest to Elymus enysii is Hordeum jubatum .
These data suggest that the genomic constitution of Stenostachys is HW, the same as Elymus enysii .
Connor H. E. and Edgar E. 2000 Flora of New Zealand . Volume V Gramineae. Manaaki Whenua Press, Lincoln , New Zealand 650 pp
Svitashev S., Bryngelsson T., Li X., Wang R.R.-C 1998 Genome-specific repetitive DNA and RAPD markers for genome identification in Elymus and Hordelymus. Genome 41 : 120-128