RESEARCH-PGR: Mechanisms of Haploid Induction in Potato

植物育种的一个关键步骤是产生近交系，即在每个基因上有相同的两个DNA序列的植物，因此培育出“真”品种。自交系可以直接作为品种种子出售，也可以用来制造稳定的F1杂交种。生产自交系最有效的方法是通过杂交获得一种被称为单倍体诱导剂的特殊品种。这种杂交产生单倍体，即具有单一亲本染色体组的后代，可以很容易地加倍以产生完美的自交系。天然单倍体诱导剂可用于玉米和马铃薯。虽然玉米单倍体诱导基因已经被鉴定，但它们并不容易适应于在番茄、油菜籽和大豆等宽叶作物中的有效利用。破译马铃薯单倍体诱导系统将提供一种亟需的替代方案。该项目将对马铃薯中的相关基因进行定位和表征。这些知识将使私人和公共育种计划能够操纵相应的基因，并在其他作物中实现类似甚至更好的单倍体诱导系统。在每种作物系统中，单倍体的轻松产生将使育种周期加快数年，最终在应对作物面临的新挑战(如疾病或干旱胁迫)方面提供更大的动力和灵活性。在培训和宣传方面，该项目将使来自代表性不足社区的年轻学生熟悉科学研究和职业，并通过制作和传播学习视频等一系列活动，培训高级学生和专业人员适用于植物育种的基因组方法。它可能是由于孤雌生殖，即未受精的卵细胞发展到胚胎发生；通过基因组消除，从胚胎中脱落一个亲本基因组；或者，由于尚未确定的受精缺陷。在所有情况下，导致这一结果的分子事件都是调节性发育和基因组维持的核心。本项目的目标是确定控制马铃薯单倍体诱导的遗传因素，并破译它们的作用方式。在此之前，一个广泛的作图群体被用来确定用于单倍体诱导的候选数量性状基因座。该项目的具体目标是：1)通过精细的遗传作图和遗传分析相结合的方法确定潜在的候选基因；2)通过比较细胞学和花粉中的基因表达以及花粉和种子中的基因组状态来表征单倍体诱导的机制；以及3)测试和表征优先候选基因在异源物种中的作用。该项目产生的所有数据和资源将通过长期公共数据和基因库免费获取。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

A critical step in plant breeding is the production of inbreds, plants that have the same two DNA sequences at each gene and therefore breed “true”. Inbreds may be sold directly as varietal seed or used to make consistent F1 hybrids. The most efficient method to produce inbreds is through a cross to a specialized variety called a haploid inducer. This cross yields haploids, progeny with a single parental chromosome set that can be easily doubled to produce perfect inbreds. Natural haploid inducers are available for maize and for potato. Although the maize haploid inducer genes have been characterized, they are not easily adapted for efficient use in broad leaf crops such as tomato, canola, and soybean. Deciphering the potato haploid inducer system will provide a much needed alternative. This project will map and characterize the responsible genes in potato. This knowledge will then enable private and public breeding programs to manipulate the corresponding genes and achieve similar or even better haploid induction systems in other crops. In each crop system, easy production of haploids will accelerate breeding cycles by several years, ultimately providing increased power and flexibility in addressing emerging challenges to crop, such as disease or drought stress. With respect to training and outreach, the project will familiarize young students from underrepresented communities with science studies and careers and train advanced students and professionals in genomic approaches applicable to plant breeding using a combination of activities including production and dissemination of learning videos.Haploid induction is an important, but poorly understood process. It could result from parthenogenesis, the progression to embryogenesis by an unfertilized egg cell; by genome elimination, the shedding of one parental genome from the embryo; or, from yet uncharacterized defects of fertilization. In all cases, the molecular events that lead to this outcome are central to the regulation of sexual development and genome maintenance. The goal of this project is to identify the genetic factors controlling haploid induction in potato and decipher their mode of action. Previously, an extensive mapping population was developed and used to identify candidate quantitative trait loci for haploid induction. The specific objectives of this project are to: 1) identify the underlying candidate genes by a combination of fine genetic mapping and genetic analyses; 2) characterize the mechanisms underlying haploid induction by comparing the cytology and gene expression in pollen as well as the genomic states in pollen and seed; and 3) test and characterize the action of prioritized candidate genes in heterologous species. All data and resources generated by this project will be made freely accessible through long-term public data and genetic repositories.This 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.