Molecular cytogenetic characterization of Roegneria ciliaris chromosome additions in common wheat

The development of alien addition lines is important both for transferring useful genes from related species into common wheat and for studying the re lationship between alien chromosomes and those of wheat. Roegneria ciliaris (2n=4x=28, (SSYYc)-S-c-Y-c-Y-c) is reported to be a potential source of re sistance to wheat scab, which may be useful in wheat improvement. The amphi ploid common wheat-R, ciliaris and BC1F7 or BC2F6 derivatives were screened by C-banding, genomic in situ hybridization (GISH), fluorescent in situ hy bridization (FISH) and restriction fragment length polymorphism (RFLP) for the presence of R. ciliaris chromatin introgressed into wheat. Six lines we re identified as disomic chromosome additions (DA), one as a ditelosomic ad dition (Dt), two as double disomic additions (dDA) and one as a monosomic c hromosome addition (MA). RFLP analysis using wheat homoeologous group-speci fic clones indicated that the R. ciliaris chromosomes involved in these lin es belong to groups 1, 2, 3, 5 and 7. The genomic affinities of the added R . ciliaris chromosomes were determined by FISH analysis using the repetitiv e sequence pCbTaq4.14 as a probe. These data suggest that the R, ciliaris c hromosomes in five lines belong to the SC genome. Based on the molecular cy togenetic data, the lines are designated as DA2S(c)#1, Dt2S(c)#1L, DA3S(c)# 1, dDA1S(c)#2+5Y(c)#1, DA5Y(c)#1, DA7S(c)#1, DA7Y(c)#1 and MA?Y-c#1. Based on the present and previous work, 8 of the 14 chromosomes of R. ciliaris ha ve been transferred into wheat.