Genomic organization and phylogenetic relationships in the genus Dasypyrum analysed by southern and in situ hybridization of total genomic and cloned DNA probes.

摘要: Molecular cytogenetic methods have been used to study the controversial phylogenetic relationships between species Dasypyrum villosum (L.) Candargy (2n=2x=14) and D. breviaristatum (Lindb. f.) Frederiksen (2n=4x=28). Using total genomic DNA from two as probes for in situ hybridization chromosomes, we found that pericentromeric regions of chromosome arms both are similar, while distal show substantial differences. Two dispersed repetitive sequences were isolated: pDbKB45 is distributed along chromosomes but amplified subtelomeric pDbKB49, species, less terminal regions. Size-separated restriction enzyme digests showed many fragments, few common species. After probing Southern transfers with DNA, all lanes similar patterns although one extra small band was evident lanes. In contrast, very differences Genomic meiotic metaphases an interspecific hybrid seven bivalents origin univalents villosum. We also analysed physical organization 5S rDNA, 18S-25S rDNA a tandemly repeated sequence rye. Our data support autotetraploid breviaristatum, its genome extensive differences, so tetraploid unlikely be directly derived