Alien chromosome addition in durum wheat. II. Advanced progeny.

Alien chromosome addition in durum wheat was accomplished by backcrossing and selling an amphiploid derivative F10 strain of Triticum turgidum L. var. durum × Agropyron intermedium (Host) Beauv. The number of chromosome pairs increased from an average of 10.4 bivalents in the B1F1 to 18.5 bivalents in the B1F7 generation. Stabilization of chromosome pairing was improved as expressed in the range of bivalents (0–21 in the B1F1 and 16–21 in the B1F7 generation). Backcrossing to the durum wheat parent resulted in the elimination of some Agropyron chromosomes and in others becoming pairs. A hexaploid Agrotriticum with the constitution AABBII resulted. The I genome consists of a group of seven chromosome pairs from A. intermedium.Key words: Agrotriticum, Agropyron intermedium, chromosome pairing.