RFLP-based genetic maps of wheat homoeologous group 7 chromosomes

Abstract

Restriction fragment length polymorphism (RFLP) mapping was attempted using 18 cDNA clones, 14 anonymous and 4 of known function, which had been shown to have homologous DNA sequences on the group 7 chromosomes of wheat. The loci identified by these probes have been mapped on one or more chromosomes in this homoeologous group using linkage data derived from various F2, random inbred, doubled haploid and single chromosome recombinant populations. The maps also include three isozyme loci, five disease resistance loci, two anthocyanin pigment loci and a vernalisation response locus. The mapping data have been used to determine the extent of map co-linearity over the A, B and D genomes, the degree of RFLP variability in the three genomes and the relative efficiency of various restriction enzymes in detecting RFLPs in wheat. The strategy for future mapping in wheat, particularly the use of "alien" genomes or segments, such as that from Aegilops ventricosa used here, is discussed.

Molecular-genetic maps for group 1 chromosomes of Triticeae species and their relation to chromosomes in rice and oat

“…linkage maps show clustering of markers near the centromere. This has been observed in other studies of wheat (Dvorak and Chen 1984;Snape et al 1985;Dvofiik and Appels 1986;Curtis and Lukaszewski 1991;Chao et al 1989;Devos et al 1992Devos et al , 1993bWerner et al 1992;Lukaszewski and Curtis 1993), barley (Kleinhofs et al 1993), rye (Rogowsky et al 1992;Lukaszewski 1992), and oat (O'Donoughue et al 1992). Comparisons of the physical (Fig.…”

“…The highest degree of polymorphism was detected in chromosome 1B and the lowest in ID, in spite of the fact that one parent in the 7: aestivum cross contains 1D from 7: tauschii, the D genome progenitor of T. aestivum (McFadden and Sears 1946). Chao et al (1989) also reported the lowest level of polymorphism in the D genome of chromosome 7 of 7: aestivum. High levels of polymorphism have been reported among T. tauschii accessions (Gill et al 1991), but by chance, the accession used to produce the T. aestivum synthetic line used in this study is genetically similar to the latter's progenitor.…”

“…Although hexaploid wheat consists of genomes derived from three ancestral species, the genetic mapping of chromosomes 1, 2 (Devos et al 1993b), 3 (Devos et al 1992), and 7 (Chao et al 1989) indicate that the relative order of DNA fragments is conserved. The order of genetic loci based on genetic-linkage studies is consistent with the order determined using deletion lines, where virtually all loci can be mapped across three genomes (Werner et al 1992).…”

“…Restriction fragment length polymorphisms (RFLPs) have been assigned to wheat chromosome arms (Anderson et al 1992;Devey and Hart 1993) and RFLP linkage maps exist for hexaploid wheat (Chao et al 1989;Liu and Tsunewaki 1991;Devos et al 1992;Devos et al 19936) and its D-genome progenitor, Triticum tauschii (Coss) Schmal. (Gill et al 1991Lagudah et al 1991).…”

Mapas genéticos em plantas

“…Mapas genéticos que levaram décadas para serem desenvolvidos em virtude da restrita disponibilidade de marcadores morfológicos e isoenzimáticos foram amplamente saturados com o uso de marcas moleculares. Assim ocorreu em milho (HELENTJARIS et al, 1986), arroz (MCCOUCH et al, 1988), trigo (CHAO et al, 1989), batata (GEBHARDT et al, 1989) e tomate (TANKSLEY et al, 1992). Várias espécies para as quais os estudos de herança são restritos, e tampouco foi descrita ligação gênica entre qualquer tipo de marcador, tiveram mapas genéticos rapidamente desenvolvidos, como o eucalipto (GRATTAPAGLIA e SEDEROFF, 1994), kiwi (TESTOLIN et al, 2001) e maracujá (CARNEIRO et al, 2002).…”