Isolation of a fertile wheat-barley addition line carrying the entire barley chromosome 1H

The isolation of six of the seven possible additions of barley chromosomes to the wheat genome reported 18 years ago has made an important contributio n to gene mapping in barley, first with genes controlling isozymes and more recently DNA (molecular) markers. A fertile addition line involving barley chromosome 1H, which carries genes controlling several characters of econo mic importance, could not be isolated at that time because it caused extrem e meiotic abnormalities leading to complete sterility when added to wheat. Later the short arm of barley chromosome 1H was added to wheat as a fertile ditelosomic addition, but the non-availability of the entire barley chromo some 1H addition line has hampered the location of barley genes to the long arm of this chromosome. This problem has now been overcome cytogenetically as described herein. The resultant self-fertile disomic-monotelodisomic ad dition line carrying a pair of barley chromosome 6H and a heteromorphic 1H/ 1HS pair is more stable, and makes the wheat-barley addition line series co mplete for gene mapping work and will provide a vehicle for the possible tr ansfer of useful genes from this barley chromosome to wheat.