**9. Final considerations**

The Triticeae wild relatives continue to be important sources of genes for introducing agro‐ nomically desirable traits into common wheat and durum wheat (*Triticum durum*) [20-21]. Thus, alien gene transfer into common wheat via cross-species hybridization makes possible the resistance increasing to biotic and abiotic stresses as well as the quality improving [22-23]. Several species such as of the genera *Aegilops*, *Secale* and *Thinopyrum* have been ex‐ tensively used in hybridizations with common wheat, thus proving to be a valuable source of genes [3, 24-25].

In all these examples, the genomic *in situ* hybridization methodology can be used to estab‐ lish the cytogenetic constitution of interspecific or intergeneric hybrids. In addition, this technique allows for a fine-scale characterization of the chromosome structure. Currently, the technique has been used in parallel to different strategies, such as C-banding, high mo‐ lecular weight (HMW) glutenin subunits, FISH with BACs (bacterial artificial chromo‐ somes), southern blot and molecular markers, in order to confirm the alien gene introgression into the wheat genome [26-29]. Besides, the GISH has been also collaborated in investigations about the evolutionary origin of common wheat and the genome-wide tran‐ scriptional dynamics [30].

## **Acknowledgements**

**Figure 8.** Post-hybridization baths and probe detection. (A) Washing of the slides in a water bath at 42 °C. (B) Disposal of the saline-sodium citrate (SSC) solution. (C) Addition of the next SSC solution. (D) Addition of 4×SSC + 0.1% Tween 20 at room temperature. (E) Addition of 5% bovine serum albumin (BSA) for the blocking step. (F) Preparation of the antibody solution. (G) Addition of the antibody solution and covering with a plastic coverslip. (H) Incubation of the slides during the detection step at 37 °C. (I) Washing the Wash the slides three times for 10 min each in 4×SSC + 0.1% Tween 20 at 42 °C. These washes are needed for removing the excess of antibodies (Fig. 8I). Figures A, B, C, D, H and I:

A metaphase cell of triticale (2*n* = 56) is shown with the 14 chromosomes from rye detected by GISH in Fig. 9. This cell was hybridized with blocking DNA of wheat and rye DNA probe labeled with digoxigenin and detected with FITC (fluorescein isothiocyanate). The chromosomes are counterstained with DAPI (Fig. 9A). Fig. 9B shows the image capture of the same chromosomes with the fluorescence filter for FITC; and, in Fig. 9C, is shown the

Sandra P. Brammer; E, F, G, J, K and L: Ana R. Oliveira & Ana C. Brasileiro-Vidal.

superposition of both images.

18 Plant Breeding from Laboratories to Fields

The authors thank the following Brazilian agencies for financial support: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); and Fundação de Amparo à Ciência e Tecnologia do Es‐ tado de Pernambuco (FACEPE).
