Introgression of rye chromatin on chromosome 2D in the Portuguese wheat landrace 'Barbela'

The old Portuguese wheat landrace aggregate known as 'Barbela' shows good p roductivity under the low-fertility conditions often associated with acid s oils. The use of genomic rye DNA, in combination with 45S rDNA and the repe titive sequences dpTa1 and pSc119.2 as probes, in two sequential in situ hy bridization steps enabled the identification of all chromosomes in the 'Bar bela' wheat lines and the detection of the introgression of rye-origin chro matin onto wheat chromosome arm 2DL in two of the lines. Amplification of m icrosatellite loci using published primer pairs showed that the distal segm ent of wheat chromosome 2DL, which was involved in the rye translocation, w as deleted. The identification and characterization of small recombinant ch romosome segments in wheat-rye lines may allow their use in plant breeding programmes. Their presence in farmer-maintained material demonstrates the i mportance of maintaining, characterizing, and collecting landrace material before valuable genetic combinations are lost as uniform commercial crops a re introduced.