Speaker
Description
In plants and animals, pollen and sperm morphology are incredibly diverse across species. Cross-pollination provides a mechanism to recombine genetic variants in a population which, among other evolutionary forces, may facilitate adaptation. Across plant species, pollen morphological diversity is broadly linked to different pollination systems. However, the extent of within-species diversity is less well understood. Further on, modulating pollination mechanisms in crops presents an opportunity to improve hybrid breeding programs.
Our study aims to investigate quantitative variations in pollen and anther morphology in rye (Secale cereale L.), a wind-pollinating grass species. For this purpose, we analysed 339 rye individuals derived from a diverse set of 64 prior classified rye accessions ranging from domesticated (221), wild-like (91) and wild (4) individuals.
A PCA using reduced representation sequencing data (GBS) based on 56,713 SNPs revealed a clustering based on the degree of domestication. We quantified pollen morphology in 286 individuals using multispectral imaging flow cytometry, and measured anther length via light microscopy in 314 individuals, which revealed pronounced within-species diversity. We conducted genome-wide association scans and found five and eight genomic regions associated with pollen length and anther length, respectively. A subset of these loci overlapped with previously identified domestication loci for which the underlying trait was unknown. Our PST-FST analysis, suggests that pollen and anther traits were under selection throughout rye domestication. A population genomic analysis revealed signatures of selection at one of five loci associated with pollen length, as well as at three out of eight loci associated with anther length. Underlining that, we found significantly higher pollen and anther length in domesticated rye.
In conclusion, this suggests that selection for larger pollen grains and longer anthers occurred throughout rye domestication. Our study extends our knowledge of the genetic architecture underlying within-species pollen and anther morphological diversity and further unravels domestication traits in rye.
| Status Group | Doctoral Researcher |
|---|---|
| Poster Presentation Option | Yes, I’m willing to present as a poster. |
