Genetic differentiation in flowering time of a short-lived perennial herb driven by divergent selection

• Because flowering time influences the time available for fruit maturation, the optimal flowering time should vary among environments that differ in the length of the growing season. With field surveys and a common-garden experiment, we documented variation in flowering time among 20 populations of the perennial herb Primula farinosa growing on soils of different water availability within an 8 x 5 km area on the island Öland, SE Sweden. We tested the hypotheses that (a) among-population variation in flowering time in the field reflects genetic differentiation, (b) among-population differentiation in flowering time is larger than that at putatively neutral marker loci, and (c) genetic differentiation in flowering time is related to water availability at the sites of origin. Among-population variation in a common-garden experiment was positively correlated with variation observed among populations at their sites of origin, and among-population differentiation for start of flowering was significantly higher than at putatively neutral marker loci. In the field, flowering start tended to be positively related to soil moisture. However, among-population differentiation observed in the common-garden experiment was not related to variation in measures of water availability at the sites of origin, suggesting that factors other than soil characteristics influence the evolution of flowering time in this system of populations. The results indicate that variation in flowering time observed among natural populations of P. farinosa is the result of both genetic differentiation and phenotypic plasticity, and are consistent with divergent selection on flowering time. 

Ämnesord

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Evolutionsbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Evolutionary Biology (hsv//eng)

Nyckelord

Adaptation; Environmental heterogeneity; Flowering start; Phenology; Primula farinosa; Soil depth; Water availability

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)