Chromosome number variation in Bromus L. (Poaceae) in Khorasan and Lorestan

Bromus is a large genus of Poaceae. Some species are important as forages while some are famous weeds. This genus is distributed in different habitats of Iran by 44 species. In this project, 44 accessions of 13 species of Bromus have been studied for chromosome counting. Chromosome number of species were from 2n=2x=14 to 2n=6x=42. B. scoparius, B. sterilis, B. madritensis, B. briziformis, B. danthoniae, B. sericeus, B. pseudodanthoniae, B. tectorum, B. rubens var. rubens were diploid (2n=2x=14). In B. japonicus all accessions were triploid (2n=3x=21). B. oxyodon has 2n=4x=28 chromosome number. B. kopetdaghensis one diploid accessions with 2n=2x=14 and two hexaploid accessions 2n=6x=42 were observed for the first time. B. tomentellus was found to be pentaploid (2n=5x=35).