18-BTT: High-throughput fluorescent crossover reporters to dissect control of tomato meiotic recombination

社会面临的一大挑战是提高作物产量和质量，以满足全球人口的需求。解决这一挑战的方法之一是培育和进一步改良作物种质。例如，野生种群的抗病和抗逆性特征有助于将其引入优良的驯化品种。在这种情况下，必须在许多世代中导入有益的性状，以获得理想的改良品系。作物改良的过程依赖于在有性繁殖过程中自然发生的后代的特征重新分类。具体地说，多样性是在称为减数分裂的特殊细胞分裂过程中产生的，减数分裂导致配子(性细胞)的产生。在减数分裂过程中创造遗传多样性的一种机制被称为交叉重组。在减数分裂过程中，同源染色体在物理上配对并交换互换区域，从而产生新的遗传变异组合。然而，在许多最重要的作物物种中，染色体上的交叉重组模式高度倾斜，包括小麦、玉米、大麦和番茄。因此，尽管含有影响重要农艺性状的重要基因，但基因组的某些区域无法进行育种。这项提案将调查的具体作物是茄子番茄。番茄是全球主要农作物，年产量超过1.3亿吨。驯化番茄属于13个茄科近缘种，是提高番茄产量和抗病性状的重要野生多样性来源。在远缘杂交后，育种者必须完成多个导入循环才能获得有用的品系，这一过程依赖于减数分裂和重组。然而，低数量的重组事件和扭曲的基因组分布限制了这一过程的效率。促进或解锁重组的工具将加速番茄种质的改良。我们将开发的番茄FTL系统将使学术和工业研究人员能够快速量化重组频率。这将有助于开发调整减数分裂重组的技术，以加强育种努力和提高粮食安全。我们开发的所有工具都可以在开放获取的基础上共享。

A major challenge facing society is to improve crop yield and quality, in order to meet the needs of the global population. One means to address this challenge is to breed and further improve crop germ plasm. For example, disease and stress resistance traits from wild populations can be beneficial to introduce into elite domesticated varieties. In this case beneficial traits must then be introgressed over many generations to achieve a desirable, improved strain. The process of crop improvement relies on the trait re-assortment in offspring that occurs naturally during sexual reproduction. Specifically, diversity is generated during a specialised cell division called meiosis, which results in production of gametes (sex cells). One mechanism that creates genetic diversity during meiosis is called crossover recombination. During meiosis, homologous chromosomes physically pair and exchange reciprocal regions, which generates new combinations of genetic variation. However, crossover recombination patterns along chromosomes are highly skewed in many of the most important crop species, including wheat, maize, barley and tomato. As a consequence, some regions of the genome are inaccessible for breeding, despite containing important genes with effects on agronomically important traits. The specific crop this proposal will investigate is Solanum lycopersicum (tomato). Tomato is a major global crop with an annual yield of over 130 million tons. Domesticated tomato belongs to a tribe of 13 related Solanaceous species, which represent an important source of wild diversity for improving yield and disease resistance traits. Following wide crosses, breeders must complete multiple cycles of introgression to obtain useful lines, and this process relies on meiosis and recombination. However, low numbers of recombination events and skewed genomic distributions limits the efficiency of this process. Tools that boost or unlock recombination will accelerate improvement of tomato germ plasm. The tomato FTL system that we will develop will enable academic and industrial researchers to rapidly quantify recombination frequency. This will facilitate the development of technology to modulate meiotic recombination to enhance breeding efforts and increase food security. All of the tools we develop with be shared on an open-access basis.