Dissertation Research: Correlations in the Timing of Life History Stages: Their Origins and Consequences

9623574由该奖项资助的Venable研究探索了沙漠植物资源可用性时间变化的进化重要性。沙漠生态系统的一个显著特征是年内和年内湿度和温度的极端变化。本研究的重点是在不到一年的时间内完成其生命周期的一年生植物。研究系统车前草（Plantago insularis）是索诺兰和莫哈韦沙漠群落草食动物和花岗岩动物的重要食物来源。年生活史通过种子休眠来避免资源利用率低的间隔。为了使这一策略取得成功，种子萌发和种子生产的时间必须与每年的天气模式同步。本研究将采用田间和温室试验相结合的方法，检验发芽和开花时间变异的遗传基础，确定这些性状的适宜性结果。这些发现将有助于检验植物适应不同环境的理论。此外，将解决发芽时间和开花时间这两个发育相关性状之间的环境和遗传方面的相关性。这一知识的一个应用是选择和繁殖开花时间较早的一年生作物品种。

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.