Analysis of Structural Genomic Diversity in , , , and by Fluorescence Hybridization Karyotyping.

Fluorescence hybridization karyotypes have been widely used for evolutionary analysis on chromosome organization and genetic/genomic diversity in the wheat alliance (tribe Triticeae of Poaceae). The karyotpic diversity of , , subsp. and subsp. , and was evaluated by the fluorescence hybridization (FISH) probes oligo-pSc119.2 and pTa71 in combination with (AAC), (ACT), and (CTT), respectively. Abundant intra- and interspecific genetic variation was discovered in , , and , but not Chromosome 7 of had more variants (six variants) than the other six U chromosomes (2-3 variants) as revealed by probes oligo-pSc119.2 and (AAC). Intraspecific variation in and was revealed by oligo-pSc119.2 in combination with (ACT) and (CTT), respectively. At least five variants were found in every chromosome of and , and up to 18, 10, and 15 variants were identified for chromosomes 2 of , 4 of subsp. , and 6 of subsp. . The six accessions showed identical FISH signal patterns. A large number of intra-specific polymorphic FISH signals were observed between the homologous chromosomes of and , especially chromosomes 1, 2, 4, and 7 of , chromosome 4 of subsp. , and chromosome 6 of subsp. . Twelve and 24 accessions showed heteromorphism between homologous chromosomes. Additionally, a translocation between the short arms of chromosomes 1 and 7 of PI 551038 was identified. The FISH karyotypes can be used to clearly identify the chromosome variations of each chromosome in these species and also provide valuable information for understanding the evolutionary relationships and structural genomic variation among species.