**6. Concluding Remarks**

Modulating the recombination landscape is of supreme importance for crop breeding, since a considerable number of genes with agronomical relevance are located in crossover-poor chromosome regions. Truncation of wheat chromosomes has been shown as a very useful way of increasing the recombination frequency in their intercalary regions. This approach is, of course, inviable in diploid crops and, most likely, it does not have an immediate application in wheat production. However, it may represent a reference to investigate the reason why such regions produce more COs in the truncated chromosomes than in the standard ones. Homologous and homoeologous recombinations show similar distribution patterns, and therefore, achievements reached in the first are also of interest for the second. A structural di fferentiation of chromosomes from di fferent species has a negative e ffect on meiotic recombination between such chromosomes. This is probably a consequence of disturbances on chromosome interactions caused by the absence of synteny. In such cases, introgressions should be carried out using other methods such as radiation. Thus, the chromosome structural organization of related genomes is of interest in designing strategies of the introgression of useful genes into crops. Recent advances in the knowledge of wheat and related species' genomes will facilitate a rapid progress of future research projects aimed to introgress useful agronomical traits into wheat and other crops. Genomic datasets for wheat and some related species, which are of public access (htps://plants.ensambl.org), make possible the analysis of any region with its gene content and the comparison among di fferent species. Expression profiles are available in a considerable number of tissues, including meiotic cells. Thus, expression patterns of genes identified in di fferent species can be compared to homoeologous genes of wheat. This reinforces polyploid wheat as a very powerful model system for study, propelling it into the mainstream of the global plant research community.

**Author Contributions:** T.N. designed and wrote the work.

**Funding:** This work was supported by gran<sup>t</sup> AGL2015-67349-P from Dirección General de Investigación Científica y Técnica, Ministerio de Economía y Competitividad of Spain.

**Conflicts of Interest:** The author declares no conflict of interest.
