THE DELETION STOCKS OF COMMON WHEAT

Chromosomal breaks occurred in the progeny of a common wheat (Triticum aestivum L, em Thell; 2n = 6x = 42, genome formula AABBDD) cultivar C hinese Spring with a monosomic addition of an alien chromosome from Ae gilops cylindrica Host (2n = 4x = 28, CCDD) or A. triuncialis L, (2n = 4x = 28, UUCC) or a chromosomal segment from A, speltoides Tausch (2n = 2x = 14, SS), We identified 436 deletions by C-banding, The deletio n chromosomes were transmitted stably to the offspring, We selected de letion homozygotes in the progeny of the deletion heterozygotes and es tablished homozygous lines for about 80% of the deletions, We failed t o establish homozygous lines for most of the deletions in the short ar m of chromosome 2A and for all deletions in the short arm of chromosom e 4B, because plants homozygous for these deletions were sterile, We c ould not obtain any homozygotes for larger deletions in the long arms of chromosomes 4A, 5A, 5B, and 5D, The deletion stocks showed variatio ns in morphological, physiological, and biochemical traits, depending on the size of their chromosomal deficiency, and are powerful tools fo r physical mapping of wheat chromosomes.