9623574 Venable Research funded by this award explores the evolutionary importance of variation in the timing of resource availability for desert plants. A prominent feature of desert ecosystems is extreme variability in moisture and temperature within and among years. The focus of this study is on annual plants that complete their life cycle in less than one year. The study system, Plantago insularis, is an important food source for herbivores and granivores in Sonoran and Mohave Desert communities. The annual life history promotes the avoidance of intervals of low resource availability via seed dormancy. For this strategy to be successful, the timing of seed germination and seed production must be synchronized with yearly weather patterns. Using a combination of field and greenhouse experiments, the research will test the genetic basis of variation in germination and flowering times and ascertain the fitness consequences of these characters. Findings will allow tests of theory on plant adaptations to variable environments. In addition, environmental and genetic aspects of the correlation between two developmentally linked traits, germination time and flowering time, will be resolved. One application of this knowledge is in the selection and breeding of annual crop species for earlier flowering times.
