Near Isogenic Line variation in Circadian Rhythm and Effects on Genotypic Traits in Arabidopsis thaliana
presentationposted on 13.10.2014, 00:00 by Sarah Cheeney
Circadian rhythms are endogenous rhythms that can be set by environmental inputs such as temperature and light. One feature of circadian rhythms is the period, or duration of one rhythmic cycle; because the diurnal cycle on earth is close to 24 hours, circadian periods close to 24 hours are thought to be adaptive. I tested for the adaptive significance of the internal circadian period match to the external environment using a set of Near Isogenic Lines (NILs) of Arabidopsis thaliana that contain genotypes with wild-type periods (close to 24 hours) and short and long period genotypes. The short and long period genotypes, with the mismatch clock, germinated and transitioned to reproduction faster (bolting) and took longer to produce flowers after the bolting compared to the wild-type genotypes. The wild-type genotypes achieved a larger size at reproduction, as estimated by leaf size and number, relative to the short and long period genotypes. Match of the internal clock to the external environment also increased end-of-season biomass. One possible explanation for the increased size and biomass could be differences in underlying physiological processes which are currently being investigated in these NILs.