Selective trade-offs maintain alleles underpinning complex trait variation in plants

Abstract

Fluctuating selection in nature Natural environmental variation can lead to individuals within a species experiencing different selective parameters. Seep monkeyflower ( Mimulus guttatus ) populations are constrained by local moisture availability and the onset of summer drought. This results in a selective tradeoff between the amount of seed set, which is determined by plant size, and the timing of reproduction. Troth et al. sequenced and phenotyped 187 M. guttatus plants and identified genetic variants associated with plant and flower size and rapid flowering. In wild populations surveyed over 3 years, the magnitude of selection changed depending on the rainfall patterns. Thus, fluctuating selection may maintain genetic variation in this species. Science , this issue p. 475