Mechanisms of convergent flower color evolution above and below the species level

这个项目将调查进化是否在基因水平上是可预测的。表型趋同，即在独立的谱系中出现相似的形式，为测试遗传进化的可预测性提供了机会。不同谱系中相似的表型往往是由于遗传水平上的相似变化所致。一种可能的解释是，在产生特定表型的可能机制中，一些基因变化在进化过程中优先固定。这个项目将通过比较物种水平上和物种水平下白色花着色的遗传基础来检验偏好固定假说。中心假说预测，一系列广泛的突变将导致有色物种中的白花突变，但在物种水平上从有色花向白花的转变过程中，只有这些类别的突变的子集将被修复。利用土豆家族中的一组物种，PI将应用遗传、发育和生化方法的组合来测试这一预测。这一结果将有助于更好地理解微观进化和宏观进化变化之间的关系。这些研究将对控制和提高园艺品种和作物中的色素含量具有重要意义。植物色素，包括本项目所针对的那些，是强大的抗氧化剂，有助于丰富水果和蔬菜饮食的积极健康益处。因此，更好地了解遗传变化如何影响色素生物合成增加了改良作物物种的潜力。该项目包括针对K-12学生的当地外联活动，以促进对植物进化生物学的兴趣，并传播对植物色素对人类健康重要性的认识。

This project will investigate whether evolution may be predictable at the genetic level. Phenotypic convergence, the appearance of similar forms in independent lineages, provides an opportunity for testing the predictability of genetic evolution. Similar phenotypes in different lineages are often due to similar changes at the genetic level. One possible explanation is that, among the possible mechanisms for producing a particular phenotype, some genetic changes are preferentially fixed during the course of evolution. This project will test the preferential fixation hypothesis by comparing the genetic basis of white flower coloration above and below the species level. The central hypothesis predicts that a wide array of mutations will be responsible for white-flowered mutants within pigmented species, but only a subset of these classes of mutations will be fixed during transitions from pigmented to white flowers at the species level. Using a group of species in the potato family, the PI will apply a combination of genetic, developmental, and biochemical approaches to test this prediction. The results will lead to a better understanding of the relationship between microevolutionary and macroevolutionary change. These studies will have important implications for manipulating and enhancing pigment content in horticultural varieties and crops. Plant pigments, including those targeted by this project, are strong antioxidants that contribute to the positive health benefits of a diet rich in fruits and vegetables. Thus, a better understanding of how genetic changes affect pigment biosynthesis adds to the potential for improving crop species. The project encompasses local outreach activities for K-12 students in order to promote interest in plant evolutionary biology and to spread awareness about the importance of plant pigments in human health.