Biology subjects

Martin, A. C.

Publications and source records attributed to Martin, A. C..

20 records · Page 2Linked to original sources

bioRxiv2018

Identification and comparison of individual chromosomes of three Hordeum chilense accessions, Hordeum vulgare and Triticum aestivum by FISH

Karyotypes of three accessions of Hordeum chilense (H1, H16 and H7), Hordeum vulgare and Triticum aestivum were characterized by physical mapping of several repetitive sequences. A total of fourteen repetitive sequences were used as probes for fluorescence in situ hybridization (FISH) with the aim of identifying inter- and intra-species polymorphisms. The (AG)12 and 4P6 probes only produced hybridization signals in wheat, the BAC7 probe only hybridized to the centromeric region of H. vulgare, and the pSc119.2 probe hybridized to both wheat and H. chilense, but not to H. vulgare. The remaining repetitive sequences used in this study produced a hybridization signal in all the genotypes. Probes pAs1, pTa535, pTa71, CCS1 and CRW were much conserved, showing no significant polymorphism among the genotypes studied. Probes GAA, (AAC)5, (CTA)5, HvT01 and pTa794 produced the most different hybridization pattern. We identified large polymorphisms in the three accessions of H. chilense studied, supporting the proposal of the existence of different groups inside H. chilense species. The set of probes described in this work allowed the identification of every single chromosome in all three species, providing a complete cytogenetic karyotype of H. chilense, H. vulgare and T. aestivum chromosomes, useful in wheat and tritordeum breeding programs.

plant biology↗

bioRxiv2017

Exploiting The ZIP4 Homologue Within The Wheat Ph1 Locus Has Identified Two Lines Exhibiting Homoeologous Crossover In Wheat-Wild Relative Hybrids

Despite possessing related ancestral genomes, hexaploid wheat behaves as a diploid during meiosis. The wheat Ph1 locus promotes accurate synapsis and crossover of homologous chromosomes. Interspecific hybrids between wheat and wild relatives are exploited by breeders to introgress important traits from wild relatives into wheat, although in hybrids between hexaploid wheat and wild relatives, which possess only homoeologues, crossovers do not take place during meiosis at metaphase I. However, in hybrids between Ph1 deletion mutants and wild relatives, crossovers do take place. A single Ph1 deletion (ph1b) mutant has been exploited for the last 40 years for this activity. We show here that selection of chemical induced mutant lines possessing mutations in TaZIP4-B2 exhibit high levels of homoeologous crossovers when crossed with a wild relative. Exploitation of Tazip4-B2 mutants rather than mutants with whole Ph1 locus deletions may improve introgression of wild relative chromosome segments into wheat. Such mutant lines may be more stable over multiple generations, as multivalents causing accumulation of chromosome translocations are less frequent.\n\nKey messageExploiting the ZIP4 homologue within the wheat Ph1 locus has identified two wheat mutants through a non-GM route, which can be exploited as an alternative to the Chinese Spring ph1b mutant in wheat introgression strategies.

plant biology↗