Evaluating the Cost of Domestication in Sunflower

这项行动资助了2018财年的NSF国家植物基因组计划生物学博士后研究奖学金。该研究金支持研究员在东道实验室的研究和培训计划，研究员还提出了扩大生物学参与的计划。艾米丽迪特玛博士的研究和培训计划的标题是“评估向日葵的驯化成本”。 该奖学金的主办机构是格鲁吉亚大学和明尼苏达大学，赞助科学家是约翰·伯克博士和彼得·莫雷尔博士。有害突变存在于所有生物的基因组中。最近的证据表明，作物基因组比其野生亲戚含有更多的有害突变（即突变负荷）。 这种突变负荷可能是由驯化过程本身引起的，驯化过程的特征通常是遗传多样性的减少和对农艺性状的强烈选择。本项目旨在了解栽培向日葵中突变负荷的原因和后果。这项研究的结果将提供有关驯化相关过程如何增加有害变体以及总体突变负荷对作物性能的影响的知识。培训目标包括基因组学和基因组数据分析中的计算培训。更广泛的影响，包括制定课程计划作物进化和遗传变异的K-12 students.The相对重要性的选择性扫描与遗传漂变的有害变异的积累向日葵将推断通过测定有害突变的全基因组分布和比较突变负荷的精英品种的历史地方品种。将使用基于系统发育序列保守程度估计有害影响的计算方法来鉴定这些有害变体。这项研究将测试这些方法的解释能力，使用数百个栽培向日葵品系的性能数据，以确定识别出的有害变体解释性能变化的程度。该项目的一个全新组成部分是，它将调查有害变体的影响是否在压力环境中升高。来自野生物种的证据表明，有害突变在胁迫下有时会产生更大的影响，但环境与作物突变负荷相互作用的程度迄今尚未探讨。这项研究的结果将几乎完全集中在公开可用的数据上，将通过出版物、会议上的演示文稿进行共享，软件、代码和分析将通过GitHub访问。保留字：驯化，系统发育分析，种群基因组学，向日葵，突变负荷，有害突变，植物生物胁迫该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2018. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Dr. Emily Dittmar is "Evaluating the Cost of Domestication in Sunflower". The host institutions for the fellowship are the University of Georgia and the University of Minnesota, and the sponsoring scientists are Drs. John Burke and Peter Morrell.Deleterious mutations are present in the genomes of all organisms. Recent evidence suggests that crop genomes harbor a greater number of deleterious mutations (i.e. mutational load) than their wild relatives. This mutational load may be caused by the process of domestication itself, which is often characterized by a reduction in genetic diversity and strong selection for traits of agronomic interest. This project aims to understand the causes and consequences of mutational load in cultivated sunflower. Results from this study will provide knowledge about how domestication-related processes increase deleterious variants and the effects of overall mutational load on crop performance. Training objectives include genomics and computational training in the analysis of genomic data. Broader impacts include developing lesson plans about crop evolution and genetic variation for K-12 students.The relative importance of selective sweeps versus genetic drift on the accumulation of deleterious variants in sunflower will be inferred through a determination of the genome-wide distribution of deleterious mutations and by comparing mutational load in elite cultivars to that of historical landrace varieties. These deleterious variants will be identified using computational approaches that estimate deleterious effects based on the degree of phylogenetic sequence conservation. This study will test the explanatory power of these methods using performance data from hundreds of cultivated sunflower lines to determine how well the identified deleterious variants explain variation in performance. A completely novel component to this project is that it will investigate whether the effects of deleterious variants are elevated in stressful environments. Evidence from wild species show that deleterious mutations sometimes have greater effects under stress, but the degree to which the environment interacts with mutational load in crops has so far been unexplored. Results from this research which will focus almost exclusively on publicly available data will be shared through publications, presentations at conferences, and software, code and analyses will be accessible through GitHub. Keywords: domestication, phylogenetic analysis, population genomics, sunflower, mutational load, deleterious mutations, plant biotic stressThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.