Chromosome composition of an F2 Triticum aestivum x T. turgidum spp. durum cross analysed by DArT markers and MCFISH

Abstract

This study has employed multicolour fluorescence in situ hybridisation and Diversity Array Technology markers to determine the segregation of parental A, B and D genome material into the progeny of a cross between a hexaploid bread wheat (Triticum aestivum L. var. 2-49) and a tetraploid durum wheat (T. turgidum L. spp. durum (Desf.) var. Bellaroi). In the F2 progeny from a 2-49/Bellaroi cross, 82 out of 83 F2 plants investigated with DArT analysis had some D genome material, principally as entire chromosomes, while 40 plants had at least one complete copy of all seven D genome chromosomes. Twelve plants containing partial D chromosomes were identified. MCFISH analysis of 26 additional F2 plants of the same cross showed that all 26 plants contained varying amounts of D genome material of which three carried single A-D translocations. In addition two telocentric D genome chromosomes were detected. The D genome content of each line and the breakpoint positions of the three A-D translocations were confirmed with DArT marker analysis. Overall results indicate a random recombination of A and B genome loci from the hexaploid female parent and the tetraploid male parent in this F2 population and a significant retention of the maternal D genome material. This study illustrates that the combined application of the MCFISH and DArT techniques provides a powerful approach for the analysis of crosses between cereal genotypes of different ploidy.