Range-wide phenotypic and genetic differentiation in wild sunflower

Area of Science:

• Plant genetics and evolutionary biology
• Ecology and population genetics
• Agricultural science

Background:

• Divergent phenotypes and genotypes signal natural selection in locally adapted populations.
• Wild sunflower (Helianthus annuus L.) populations were studied across a latitudinal gradient in North America.
• Common garden phenotyping and SNP genotyping were employed to analyze diversity patterns.

Purpose of the Study:

• To characterize range-wide patterns of diversity in wild sunflower populations.
• To identify genomic regions contributing to local adaptation.
• To understand adaptive roles in a changing climate.

Main Methods:

• Phenotypic analysis of growth, plant architecture, and seed traits.
• Single-nucleotide polymorphism (SNP) genotyping for genetic diversity.
• Analysis of geographic patterns, population structure, and FST outliers.

Main Results:

• Traits like flowering time and plant height correlated significantly with latitude.
• Two distinct genetic clusters were identified, separating northern and southern populations.
• A significant FST outlier SNP was found in the HaFT2 flowering time gene.

Conclusions:

• Latitudinal differentiation in traits and allele frequencies is evident in wild sunflowers.
• This differentiation likely plays a crucial adaptive role across the species' range.
• Findings may inform adaptation strategies for a changing climate.