No abstract

In the present study, the karyotypes of six populations of Agropyron cristatum distributed from Northern Europe to Southwest Asia are reported. Their chromosome numbers were 14, 28 or 42. The karyotypcial formulae are suggested as follows: Sweden population (PI 297869), 2n = 2x = 14 = 14m; Bulgaria population (PI 636511), 2n = 2x = 14 = 8m + 6sm; Iran population (PI 401074) 2n = 4x = 28 = 10m + 18sm; Russian Federation population (PI 439948) 2n = 4x = 28 = 20m + 8sm, Russian Federation population (PI 564878), 2n = 4x = 28 = 18m + 10sm; and Iran population (PI 401080), 2n = 6x = 42 = 20m + 22sm. The relative length of the longest chromosome was 8.40 in Bulgaria population, but 4.57 in Iran population. These results indicated that discrepancies on chromosome structure and numbers existed among these populations. Sweden population is placed in 1A, and the other populations are placed in 2A for karyotype symmetry.

10 accessions of tetraploid wheat were radiated with 100 Gy 60Co γ-ray. The germination energy, germination rate, special characters (secondary tillering, stalk with wax powder, and dwarf), meiotic process, and high-molecular-weight glutenin subunits (HMW-GSs) were observed. Different species has different radiation sensibility. With 1 seed germinated (5%), T. dicoccum (PI434999) is the most sensitive to this dose of radiation. With a seed germination rate of 35% and 40%, this dose also affected T. polonicum (As304) and T. carthlicum (As293). Two mutant dwarf plants, T. turgidum (As2255) 253-10 and T. polonicum (As302) 224-14, were detected. Abnormal chromosome pairings were observed in pollen mother cells of both T. dicoccoides (As835) 237-9 and T. dicoccoides (As838) 239-8 with HMW-GS 1Ax silent in seeds from them. Compared with the unirradiated seed of T. polonicum (As304) CK, a novel HMW-GS was detected in seed of T. polonicum (As304) 230-7 and its electrophoretic mobility was between 1By8 and 1Dy12 which were the HMW-GSs of Chinese Spring. These mutant materials would be resources for wheat breeding.