Chromosome composition, stability and fertility of alloploids between Triticum turgidum var. carthlicum and Thinopyrum junceiforme.

Alloploids, most of them hexaploid, from crosses between tetraploid wheat, Triticum carthlicum, and the perennial tetraploid Thinopyrum junceiforme were analysed for chromosome composition, stability and fertility using genomic in situ hybridization and meiotic analysis. The alloploids differed in their total number of chromosomes, 38-47 + telocentrics in "hexaploids" and 54 and 56 in "octoploids", and also in their number of Thinopyrum chromosomes (8-15). Translocations, mostly Robertsonian ones, were frequently found and intergenomic pairing was found to occur during meiosis. The stability was low which is reflected in the variability in chromosome number and in the number of univalents per PMC (2.3-4.0). The seedset was lower than in wheat, but high enough to secure a safe propagation and preservation. The alloploids are discussed in relation to widening the genetic variation of breadwheat and wheat breeding.