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获得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间水分和温度的极端变化。这项研究的重点是在不到一年的时间内完成生活史的一年生植物。研究系统名为车前草，是索诺兰和莫哈德沙漠社区食草动物和食草动物的重要食物来源。年生活史有助于避免因种子休眠而出现资源利用率低的间隔期。为了使这一战略取得成功，种子萌发和种子生产的时间必须与每年的天气模式同步。通过田间试验和温室试验相结合，这项研究将测试种子萌发和开花时间变异的遗传基础，并确定这些性状的适合性后果。这些发现将允许对植物适应不同环境的理论进行测试。此外，发芽时间和开花时间这两个发育相关性状之间的相关性的环境和遗传方面的问题将得到解决。这一知识的一个应用是在一年生作物品种的选择和育种中提早开花。

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.