II.44. Agronomic performance of eight chromosome barley in Montana.
G. A. Wiebe, Collaborator, USDA, ARS, Beltsville, Maryland 20705, USA.
An extra pair of chromosomes has been added to barley. This extra chromosome is made up of part of chromosome 5 and part of chromosome 7, and commonly known as an interchange chromosome. During the addition process the end genes of this extra chromosome were deleted thus preventing its pairing with the normal chromosomes from which it was derived. Such an extra chromosome is functional in the egg and occasionally transmitted through the pollen. The latter event gives an 8 paired barley. The lines so established have increased the gene content of the barley plant by about 5 percent. We visualize that similar lines can be made from other interchanged chromosomes for which there are 21 basic combinations. The scheme outlined also should make it possible to establish 9 paired barleys, etc. Additions to the genome of barley in this way should help the breeder to obtain results not possible with the 7 pair genome.
Results of yield trials at Bozeman irrigated, Havre dryland, Sidney dryland, Kalispell dryland and irrigated, Moccasin dryland and Huntley dryland and irrigated are shown in Table 1. Average nursery mean yield ranged from 4735 to 2072 kg/ha. Yield of the eight chromosome types was significantly lower at all locations than Unitan and Steptoe except at Bozeman where the late type was only 540 kg/ha below Unitan.
