Rapid and Targeted Introgression of Traits via Genome Elimination

PI: Luca Comai（加州大学戴维斯分校）-PI: Ek Han Tan（加州大学戴维斯分校）；安妮·布里特（加州大学戴维斯分校）；Awais Khan（秘鲁国际马铃薯中心）；合作者：Ravi Maruthachalam （IISER-TVM，印度）；Meredith Bonierbale（秘鲁国际马铃薯中心）：一种常见的植物育种程序包括将抗病等有价值的性状从野生近缘种转移到作物品种中。为了实现这一目标，育种者将野生品种与作物品种杂交。这种结果被称为杂交，它混合了父母双方的基因。然而，野生品种的大部分基因不适合农业，必须抛弃。这是通过对作物品种的反复杂交，加上对感兴趣的性状的选择来完成的，这个过程被称为回交，通常需要长达10年的时间。这构成了培育新品种的巨大瓶颈。因此，当人类的生计依赖于新品种和改良品种的快速发展时，面对意想不到的作物挑战，缩短开发时间尤为关键。本项目解决了这一需求。该项目旨在以马铃薯为试验系统，开发一种将有用性状快速部署到作物中的方法。加州大学戴维斯分校和国际马铃薯中心之间的合作还将培训研究生和本科生进行基因组育种。所开发的方法将适用于许多作物品种，对基础研究和应用研究都很有用。单倍体诱导（Haploid induction）是一种产生具有单一基因组而不是两个亲本基因组的植物的过程，它可以显著缩短培育新品种所需的时间。然而，目前还没有办法解决连锁阻力的问题，即有害基因与理想基因之间普遍存在的负相关。该项目团队发现了一种方法，可以方便地将选定的基因组区域转移到目标品种，为育种提供了一种新的解决方案，使育种更快、更有效。该工作计划将模式植物拟南芥的快速测试与马铃薯天然和工程单倍体诱导剂系统的探索相结合，以开发快速和简单的作物新性状渗入方法。具体目标是：1)以马铃薯单倍体诱导剂和着丝粒组蛋白H3为基础，开发和发展马铃薯单倍体诱导系统。2)利用不同类型的重组机制，将已定义的染色体片段从供体基因组渗入受体基因组。本工作产生的有用马铃薯和拟南芥株系将分别存放在GRIN NRSP-6 （http://www.ars-grin.gov/nr6/）和ABRC （https:/www.arabidopsis.org/）库存中心。进展和资源也将从首席研究员的网站（http://comailab.genomecenter.ucdavis.edu/）链接。

PI: Luca Comai (University of California DavisCo-PIs: Ek Han Tan (University of California Davis); Anne Britt (University of California Davis); Awais Khan (International Potato Center, Peru); Collaborators : Ravi Maruthachalam (IISER-TVM, India); Meredith Bonierbale (International Potato Center, Peru)A common plant breeding procedure involves moving valuable traits, such as disease resistance, from wild relatives to crop varieties. To achieve this, breeders cross a wild variety to a crop variety. The result is called a hybrid, and it mixes genes from both parents. Most of the genes from the wild variety, however, are unsuited for agriculture and must be cast away. This is done by repeated crossing to the crop variety, coupled to selection for the trait of interest, a process called backcrossing that often requires as many as 10 years. This constitutes a dramatic bottleneck to developing new varieties. Therefore, shortening the development time is particularly critical in the face of unexpected crop challenges when human sustenance depends on the rapid development of new, improved varieties. This project addresses this need. It aims at developing a method for rapid deployment of useful traits into crops, using potato as the experimental system. The collaboration between University of California-Davis and the International Potato Center will also train graduate and undergraduate students in genomic-based breeding. The method developed will be applicable in many crop species and will be useful for both basic and applied research.Haploid induction, a process that generates plants with a single genome instead of the two parental ones, can significantly shorten the time it takes to make new varieties. However, no methods have resolved the problem of overcoming linkage drag, the common, negative association of deleterious genes with desirable ones. The project team discovered a method to facilitate the transfer of selected genomic regions to a target variety, providing a novel solution to make breeding faster and more efficient. The work plan combines rapid testing in the model plant Arabidopsis with exploration of natural and engineered haploid inducer systems in potato to develop methods for rapid and simple introgression of new traits in crops. The specific objectives are to 1) Exploit and develop haploid induction systems in potato, based on the S. tuberosum phureja haploid inducer as well as on manipulation of centromeric histone H3. 2) Engineer introgression of defined chromosomal segments from a donor to a recipient genome using different types of recombination mechanisms. Useful potato and Arabidopsis lines produced by this work will be deposited in, respectively, GRIN NRSP-6 (http://www.ars-grin.gov/nr6/) and the ABRC (https:/www.arabidopsis.org/) stock centers. Progress and resources will also be linked from the Principal Investigator's web site (http://comailab.genomecenter.ucdavis.edu/).