Cytological identification of an chromosome carrying stripe rust resistance in wheat.

(UUSS), an important sources for wheat improvement, originated from chromosome doubling of a natural hybrid between (UU) with (SS). The karyotype was poorly characterized by fluorescent in situ hybridization (FISH). The FISH probe combination of pSc119.2, pTa71 and pTa-713 identified each of the 14 pairs of chromosomes. Our FISH ideogram was further used to detect an chromosome carrying stripe rust resistance in the background of wheat lines developed from crosses of the stripe rust susceptible bread wheat cultivar Yiyuan 2 with a resistant accession. Among the 15 resistant BCF lines, three were 2S + 4S addition lines (2n = 46) and 12 were 2S(2B) or 2S(2D) substitution lines that were confirmed with SSR markers. SSR marker can be used to trace 2S in common wheat background. Chromosome 2S probably carries gametocidal() gene(s) since cytological instability and chromosome structural variations, including non-homologous translocations, were observed in some lines with this chromosome. Due to the effects of photoperiod genes, substitution lines 2S(2D) and 2S(2B) exhibited late heading with 2S(2D) lines being later than 2S(2B) lines. 2S(2D) substitution lines were also taller and exhibited higher spikelet numbers and longer spikes.