Reproductive development is a highly regulated process in composite plants like sunflower. The individual florets in a sunflower disk have a two day period of maturation such that the buds open to present pollen on the first day and then the stigma opens to receive pollen on the second day. This regulation of the daily timing of these events is critical for effective animal or self pollination, and it is coordinated both by internal rhythms driven by the circadian clock and external signals like daily temperature fluctuations. We have revealed that different wild and cultivated sunflower accessions vary in the timing of floret maturation events, and in previous summer we performed experiments to map the genetic basis of this natural variation through time-lapse imaging of genetic mapping panels in the field. This summer, we plan additional field experiments to investigate candidate genes identified by the first of those experiments, and plan to continue scoring videos and processing tissue for genotyping for the second experiment. In the end, by studying the natural variation in these floral developmental timing traits and their sensitivities to environmental cues, we aim to reveal pathways by which the clock and the environment coordinate this fundamental and agronomically important environmental process.
The undergraduate researchers will grow, care for, and sample tissue for plants grown to assess candidate gene influence on floret maturation timing traits in the field. This fieldwork will involve potting and caring for plants in outdoor conditions, periodic travel to and from our field site at UC Davis, filming plants, collecting tissue, and taking other phenotypic information. They will also be involved in data entry and image analysis, and there may also be opportunities for learning DNA or RNA extraction and other molecular biology techniques. The student will 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 field conditions for extended periods, and they will be expected to follow guidelines for safely doing so. Students who are interested in working full time (wage or stipend support may be available) are especially encouraged to apply.