One way is through CATS, the Crop Analysis Tools Suite, which can be found at https://cats.ipk-gatersleben.de/. Here, you will discover a range of useful tools and a link to the BLAST servers for barley, rye, and wheat. These BLAST servers, where BLAST stands for Basic Local Alignment Search Tool, are hosted on a specialized GALAXY platform (https://galaxy-web.ipk-gatersleben.de/). On GALAXY, you can upload your sequence information of interest and search it against the genomes available. GALAXY offers various genomes from crop plants such as barley, wheat, rye, faba bean, Brassica, and oat. With the rapid progress in genome sequencing, I anticipate that more crops will soon be included in this list. If you are searching for orthologous genes in barley or wheat, for example, you can choose from different reference genomes, including the pan-genome that contains information from different genotypes of a species. I recommend utilizing the genomic information for the specific genotype you are working with since there is considerable variation within a species. You may also consider re-sequencing your candidate gene before proceeding to the next step.
If you are specifically working with barley, I would highly recommend BARLEX (http://barlex.barleysequence.org/), which stands for BARLey genome EXplorer. When you visit BARLEX, you will initially be presented with recent updates, which may seem a bit peculiar. However, don't be confused - the vital features of the tool are accessible through the main menu and underneath the update block. Here, you can perform BLAST searches against different versions of the barley reference genome. Additionally, you can search for information regarding genome structure, individual genes, markers, and transposons. I want to emphasize the significance of the information on single genes. If you have the gene ID available, such as for example “HORVU.MOREX.r3.7HG0679980.1” for barley Squamosa promoter-binding-like protein 14 (Spl14), you can enter it into the search bar - please ensure you select the correct genome version - and retrieve information on the coding sequence, protein, as well as gene structure and location. You will also find a list of older gene IDs, which can help you connect previous gene information with the current genome version.
If you are working in the same field, I encourage you to explore these tools and gain your own experiences.