Allopolyploidization may initiate rapid evolution due to heritable karyotypic changes. The types and extents of these changes, the underlying causes, and their effects on phenotype remain to be fully understood. Here, we designed experimental populations suitable to address these issues using a synthetic allotetraploid wheat. We show that extensive variation in both chromosome number (NCV) and structure (SCV) accumulated in a selfed population of a synthetic allotetraploid wheat (genome SbSbDD). The combination of NCVs and SCVs generated massive organismal karyotypic heterogeneity. NCVs and SCVs were intrinsically correlated and highly variable across the seven sets of homoeologous chromosomes. Both NCVs and SCVs stemmed from meiotic pairing irregularity (presumably homoeologous pairing) but were also constrained by homoeologous chromosome compensation. We further show that homoeologous meiotic pairing was positively correlated with sequence synteny at the subtelomeric regions of both chromosome arms, but not with genic nucleotide similarity Our results implicate factors influencing meiotic homoeologous chromosome pairing and reveal the type and extent of karyotypic variation and its immediate phenotypic manifestation in synthetic allotetraploid wheat. This has relevance for our understanding of allopolyploid evolution.
- Award ID(s):
- 1822162
- NSF-PAR ID:
- 10248577
- Date Published:
- Journal Name:
- Agronomy
- Volume:
- 10
- Issue:
- 8
- ISSN:
- 2073-4395
- Page Range / eLocation ID:
- 1059
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Summary per se . Both NCVs and SCVs impacted phenotypic traits but only NCVs caused significant reduction in reproductive fitness. -
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We developed aneuploid tetraploid maize lines that contain three copies of chromosome 10 derived from inbred lines B73 and H99. We were able to identify the parental origin of each copy of chromosome 10 in the materials using oligonucleotide‐based haplotype‐specific chromosome painting.
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