Many plant species monitor day length as an environmental cue for the annual timing of the growing season since photoperiod is a very reliable indicator of calendar date for a given location. However, since the time of year most favorable for reproduction varies geographically, different populations have evolved different responses to day length to adapt to this spatial heterogeneity in seasonal timing. Understanding how these adaptations to climate variation across space have evolved will help us understand mechanisms by which plants can evolve to cope with a changing climate over time. We are studying the genetics of this important aspect of local adaptation in the common monkeyflower, Mimulus guttatus. Populations of this species will only flower at times of year when days are sufficiently long, but the threshold day length varies with elevation such that populations at high elevation (i.e., areas with later starting springs) require longer day lengths than populations at low elevation. We have identified several regions of the genome involved in divergence in this trait between high and low elevation populations, and we are now developing additional genetic mapping resources to narrow down these regions to the individual causative genes. Similarly, we are breeding low elevation alleles into high elevation backgrounds to do follow up studies of gene expression to see how these variants impact the environmental and genetic regulation of flowering. On another front, we are pursuing studies how populations of a related species, Mimulus laciniatus, differ in how the environment experienced by parental plants influences offspring phenotypes and why this variation could be adaptive. The SPUR students will assist with these breeding and mapping projects through contributing to plant growth, crossing, phenotyping, and genotyping efforts.
The undergraduate researchers will grow, care for, and cross monkeyflowers as part of our efforts to develop advanced generation mapping panels and isogenic lines, and they may also be involved in scoring of germination and flowering of these plants under controlled photoperiod conditions. They will collect tissue for DNA or RNA extraction, and depending on progress and success, may also take part in DNA isolation, genotyping, gene expression, tissue culture, or plant transformation efforts. The student may also be involved in scoring plant traits using traditional methods or image analysis. The student will be encouraged to participate in weekly Blackman lab group meetings as well.
Students with strong interests in plant-environment interaction, genetics, evolution, and ecology will find the experience most rewarding. Attention to detail and good record keeping skills are essential. The student should be comfortable and enthusiastic about working in greenhouse and growth chamber conditions for extended periods, and they will be expected to follow guidelines for safely doing so.