Identification of wheat and tritordeum chromosomes by genomic in situ hybridization using total Hordeum chilense DNA as probe

Constructing an alternative wheat karyotype using barley genomic DNA

The established karyotype was generated by genomic in situ hybridization (GISH) using total barley genomic DNA as labelled probe on mitotic metaphase bread wheat chromosomes. GISH produced specific banding signals on 16 of the 21 chromosome pairs. The following chromosomes showed distinctive banding patterns: 2A, 3A, 4A, 5A, 6A, 7A, 1D, 2D, 7D and all of the B chromosomes. The remaining chromosomes showed either faint bands or no hybridization signals at all. The in situ hybridization patterns corresponded to the GAA-satellite sequence, which is similar to the N-banding pattern in wheat. In situ hybridization by labelling total barley genomic DNA made it possible to identify most of the bread wheat chromosomes. The present paper describes a GISH-banding method for hexaploid wheat chromosomes. It is a valuable alternative method for fast chromosome selection without using FISH repetitive DNA clones.

Chromosomal distribution of telomeric and telomeric-associated sequences in Hordeum chilense by in situ hybridization

The chromosomal distribution of telomeric repeat pAtT4 from Arabidopsis thaliana and telomeric associated repetitive sequence HvT01 from Hordeum vulgare have been studied by FISH (fluorescence in situ hybridization) in two accessions (H1 and H7) of Hordeum chilense. The telomeric sequence pAtT4 is present at the end of all chromosome arms in H1 and H7 accessions. In contrast, the telomeric associated sequence homologous to HvT01 showed variability for size, intensity and position of the signals for each line. In H1, HvT01 was present in every chromosome whereas only four chromosomes were labeled in H7 accession. Physical distribution of GAA-satellite sequence on both H1 and H7 metaphase chromosomes was also studied. Polymorphism for hybridization signals between the two accessions for GAA-banding pattern was also found. Based on differences in position and intensity of the hybridization signals found for both GAA and HvT01-homologous sequences, karyotypes for the in situ hybridization patterns are presented for H1 and H7 accessions of H. chilense.

Identification of intergenomic translocations involving wheat, Hordeum vulgare and Hordeum chilense chromosomes by FISH

Intergenomic translocations between wheat, Hordeum chilense and Hordeum vulgare have been obtained in tritordeum background. Advanced lines from the crosses between three disomic chromosome addition lines for chromosome 2Hv, 3Hv, and 4Hv of barley (Hordeum vulgare) in Triticum aestivum cv. Chinese Spring (CS) and hexaploid tritordeum (2n = 6x = 42, AABBHchHch) were analyzed. Multicolor FISH using both genomic DNA from H. chilense and H. vulgare were used to establish the presence and numbers of H. vulgare introgressions into tritordeum. Interspecific H. vulgare/H. chilense and intergeneric wheat/H. vulgare and wheat/H. chilense translocations were identified. Frequencies of plants containing different kinds of intergenomic translocations between chromosome arms are presented. These lines can be useful for introgressing into tritordeum characters of interest from H. vulgare.