The genomic relationship of the diploid Bromus variegatus to Bromus inermis

Abstract

The diploid species Bromus variegatus Bieb. was crossed to Bromus inermis Leyss (4x, 8x). Chromosome pairing in each of the six F1 hybrid plants of B. variegatus × B. inermis (4x) fit a 2:1 genomic model of chromosome pairing, which indicated that the B. variegatus genome was more closely related to the A or B genome of B. inermis than A and B were related to each other. A breakdown of microsporocytes was observed in the B. variegatus × B. inermis (8x) hybrid. However, chromosome pairing suggested that the B. variegatus genome was differentiated from the A and B genomes of octoploid B. inermis.Key words: Bromus, diploid, genome, affinity.