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SUMMARY Aegilopsspecies represent the most important gene pool for breeding bread wheat (Triticum aestivum). Thus, understanding the genome evolution, including chromosomal structural rearrangements and syntenic relationships amongAegilopsspecies or betweenAegilopsand wheat, is important for both basic genome research and practical breeding applications. In the present study, we attempted to develop subgenome D‐specific fluorescencein situhybridization (FISH) probes by selecting D‐specific oligonucleotides based on the reference genome of Chinese Spring. The oligo‐based chromosome painting probes consisted of approximately 26 000 oligos per chromosome and their specificity was confirmed in both diploid and polyploid species containing the D subgenome. Two previously reported translocations involving two D chromosomes have been confirmed in wheat varieties and their derived lines. We demonstrate that the oligo painting probes can be used not only to identify the translocations involving D subgenome chromosomes, but also to determine the precise positions of chromosomal breakpoints. Chromosome painting of 56 accessions ofAe. tauschiifrom different origins led us to identify two novel translocations: a reciprocal 3D‐7D translocation in two accessions and a complex 4D‐5D‐7D translocation in one accession. Painting probes were also used to analyze chromosomes from more diverseAegilopsspecies. These probes produced FISH signals in four different genomes. Chromosome rearrangements were identified inAegilops umbellulata,Aegilops markgrafii, andAegilops uniaristata, thus providing syntenic information that will be valuable for the application of these wild species in wheat breeding.
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Chromosome‐specific painting unveils chromosomal fusions and distinct allopolyploid species in the Saccharum complex
Summary Karyotypes provide key cytogenetic information on the phylogenetic relationships and evolutionary origins in related eukaryotic species. Despite our knowledge of the chromosome numbers of sugarcane and its wild relatives, the chromosome composition and evolution among the species in theSaccharumcomplex have been elusive owing to the complex polyploidy and the large numbers of chromosomes of these species.Oligonucleotide‐based chromosome painting has become a powerful tool of cytogenetic studies especially for plant species with large numbers of chromosomes. We developed oligo‐based chromosome painting probes for all 10 chromosomes inSaccharum officinarum(2n = 8x = 80). The 10 painting probes generated robust fluorescencein situhybridization signals in all plant species within theSaccharumcomplex, including species in the generaSaccharum,Miscanthus,NarengaandErianthus.We conducted comparative chromosome analysis using the same set of probes among species from four different genera within theSaccharumcomplex. Excitingly, we discovered several novel cytotypes and chromosome rearrangements in these species.We discovered that fusion from two different chromosomes is a common type of chromosome rearrangement associated with the species in theSaccharumcomplex. Such fusion events changed the basic chromosome number and resulted in distinct allopolyploids in theSaccharumcomplex.
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- Award ID(s):
- 2029959
- PAR ID:
- 10371068
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 233
- Issue:
- 4
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- p. 1953-1965
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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