THE RELATIONSHIP BETWEEN THE GENOME OF TRITICUM URARTU AND THE A AND B GENOMES OF TRITICUM AESTIVUM

Abstract

Triticum urartu (2n = 14) was crossed with T. aestivum lines ditelosomic for chromosomes of the A and B genomes. Except for telosome 4Aα, the rest of the telosomes of the A genome paired in these hybrids while telosomes of the B genome did not pair. This indicates that T. urartu cannot be the donor of the B genome of 4x and 6x wheat, but carries an A genome. Compared to the rest of the hybrids, pairing of T. urartu chromosomes was significantly reduced in hybrids deficient for chromosome arms 5AS or 5BS. It is suggested that this reduction in chromosome pairing resulted from the absence of genes which promote homoelogous pairing and which are normally present on chromosome arms 5AS and 5BS in Chinese Spring.