Submitted to: International Symposium of Molecular Breeding of Forage Turf
Publication Type: Proceedings
Publication Acceptance Date: 3/1/2005
Publication Date: 7/3/2005
Citation: Tuna, M., Barzani, O., Vogel, K.P., Golan-Goldhirsh, A. 2005. Random amplified polymorphic dna analysis in section pnigma of the genus bromus L. p.265. In M.O. Humphreys (ed.). Proc. Int. Symp. of Molecular Breeding of Forages and Turf, 4th, Aberystwyth, Wales. 3-6 July 2005. Wageningen Academic Publishers. Wageningen. The Netherlands. Interpretive Summary: Smooth bromegrass and meadow bromegrass are widely used in North American in pastures. These species have multiple sets of chromosomes (they are polyploids) which gives them a complex genetic structure. The objective of this study was to use molecular markers to determine the genetic relationship among different strains of these species and strains of diploid species of bromegrass that have only two sets of chromosomes. The results indicate that smooth bromegrass and meadow bromegrass are more closely related to each other than are the diploid bromegrass species. The results indicate polyploid smooth bromegrass and meadow bromegrass have different numbers of copies of the same sets of chromosomes which originated from the diploid bromegrass species. This information can be used by forage breeders to develop improved pasture grasses.
Technical Abstract: The section Pnigma of the grenus Bromus consists of about 60 species. The genetic relationship among species within the section is poorly known. The objective of this study was to assess the phylogenetic relationships among species of this section of Bromus by using random amplified polymorphic DNA (RAPD) molecular markers. Cluster analyses was used to analyze the results and determine genetic relationship among the species and accessions within species. Smooth bromegrass (Bromus inermis) and meadow bromegrass (B. riparius) are the principal cultivated bromegrass species in North America and were included in the analyses as members of the section Pnigma. Four diploid Bromus species and B. ciliatus, a tetraploid, could be distinguished from the other species by specific markers. Tetraploid and octaploid accessions of B. inermis clustered together as did octaploid and decaploid accessions of B. riparius and B. biebersteinii. The polyploid species were more closely related to each other than were the diploid species. Pumpelly's bromegrass accessions (B. inermis pumpellaneous) which are native to North America clustered with the smooth bromegrass accessions which are native to Europe and Asia. The results indicate that diploid Bromus species of the section Pnigma are more distinctly related than the polyploids which probably derived from them. The results support previous cytogenetic research which indicated that Eurasian polyploid species of section Pnigma of Bromus are closely related and carry different number of copies of the same genomes.