Pollen and anther morphological variation in rye was shaped by domestication

Area of Science:

• Plant reproductive biology
• Evolutionary genetics
• Agronomy

Background:

• Pollen and sperm morphology exhibit significant interspecific variation, often linked to pollination systems.
• Within-species pollen morphological diversity remains less understood across plant species.
• Rye (Secale cereale L.), a wind-pollinating grass, was studied to investigate within-species pollen and anther diversity.

Purpose of the Study:

• To explore the extent of within-species pollen and anther morphological diversity in rye.
• To understand the genetic architecture and evolutionary pressures shaping these traits during domestication.

Main Methods:

• Analysis of 339 individuals from 64 diverse rye accessions (domesticated, feral, wild).
• Population structure analysis to reveal differentiation gradients.
• Genome-wide association scans (GWAS) for pollen and anther traits.
• P_ST-F_ST analysis and population genomic analyses to detect selection.

Main Results:

• Pronounced within-species diversity in pollen and anther morphology was observed in rye.
• Pollen and anther traits exhibit a polygenic architecture with medium to high heritability.
• A subset of identified loci overlapped with known domestication loci.
• Evidence of selection on pollen and anther traits throughout rye domestication, with signatures of selection at 37% of identified loci.

Conclusions:

• Selection for larger pollen grains and longer anthers occurred during rye domestication.
• The study elucidates the genetic architecture of within-species pollen and anther morphological diversity.
• Unravels key domestication traits in rye (Secale cereale L.).