ARS | Publication request: Chromatin Structure of Wheat Breeding Lines Resistant to Wheat Streak Mosaic Virus.

Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: January 26, 2010
Publication Date: February 5, 2010
Citation: Ali, .N., Kapalande, H.V., Graybosch, R.A., Heslop-Harrison, J., Schwarzacher, T. 2010. Chromatin Structure of Wheat Breeding Lines Resistant to Wheat Streak Mosaic Virus. Meeting Proceedings. Unable to locate on-line publication.

Technical Abstract: Wheat Streak Mosaic Virus (WSMV) is an important disease limiting wheat production, however no WSMV resistance effective above 18°C is present within the primary genetic pool of wheat (Triticum aestivum L.). In contrast, the wild relative Thinopyrum intermedium (2n=6x=42) shows good resistance to WSMV, harbouring the resistant gene Wsm-1. Hybrids and back crosses have been developed with the aim to transfer the Th. intermedium Wsm-1 gene to wheat (Divis et al. 2005). Six populations were selected, each comprising resistant and susceptible lines. The WSMV resistant cultivar ‘Mace’, derived from one of these populations and released recently contains Th. intermedium chromatin (Graybosch et al. 2009). We have used fluorescent in situ hybridization (Schwarzacher et al. 1992) with total genomic DNA from Th. intermedium to screen pairs of resistant and susceptible lines from above populations. Repetitive DNA probes including the 5S, 45S rDNA and the D-genome specific repeat dpTa1 allowed characterization of the wheat-alien recombinant chromosomes. While susceptible lines did not contain detectable Th. intermedium chromatin, most resistant lines did. In most cases a small Th. intermedium arm with a strong dpTa1 site near the centromere was observed translocated onto the long arm of chromosome 4D of wheat. In some lines additional small fragments where observed on another D-genome specific chromosome and chromosome 1B of wheat.