Towards new Brassica crops: genetic improvement of Brassica hexaploids

油菜（Brassica napus）是中国和德国的主要油料作物。然而，该物种是高度近交的，并且缺乏其他主要作物如小麦的环境耐受性。为了拓宽油菜籽生产的遗传基础，提出了一种创新的长期育种解决方案：将不同的芸苔属作物物种聚集在一起进行种间杂交，以产生新的作物类型，这些作物类型受益于增加的遗传多样性、杂交活力和环境耐受性。然而，为了开发这种新作物，仍然需要解决几个问题。首先，需要确保基因组稳定性，使得可以产生世代保持高生育力的真育种系。第二，需要在新的作物类型中创造广泛的遗传多样性，以供选择，这就需要从不同来源（物种和基因型）生产种质。最后，这种新的作物类型必须已经证明具有农艺潜力，以及可能优于目前的传统油菜品种。为了解决这些问题，我们建议将联合收割机正在进行的研究工作与中国和德国产生的芸苔属种质类型的先进世代相结合。将采用多方面的方法：1）使用高通量基因分型和细胞遗传学研究来自不同来源的高级、可纯化的稳定异源六倍体系中染色体重排和减数分裂行为之间的关系; 2）在现有种质的基础上以及在通过不同的中国和德国种质之间的杂交和重组产生的新产生的品系中扩大遗传多样性，以及3）利用田间表型分析和QTL定位技术对这些优良种质的农艺性状进行筛选和评价，为中国、德国和世界范围内油菜高产油料、蔬菜和生物质能源作物的开发提供参考。

Rapeseed (Brassica napus) is a major oil crop in both China and Germany. However, this species is highly inbred, and lacks the environmental tolerances of other major crops such as wheat. In order to broaden the genetic basis for rapeseed production, an innovative long-term breeding solution has been proposed: to bring together different Brassica crop species in interspecific hybridisation events to make new crop types which benefit from increased genetic diversity, hybrid vigour and environmental tolerances. However, several problems still need to be addressed in order to develop this new crop. Firstly, genomic stability needs to be ensured, such that true-breeding lines can be produced which maintain high fertility from generation to generation. Secondly, extensive genetic diversity needs to be created in the new crop type for selective purposes, necessitating production of germplasm from diverse sources (both species and genotypes). Finally, this new crop type has to have demonstrated agronomic potential as well as possible advantages over current conventional rapeseed varieties. In order to address these concerns, we propose to combine ongoing research work and advanced generations of Brassica germplasm types generated in both China and Germany. A multi-faceted approach will be used to 1) investigate the relationship between chromosome rearrangements and meiotic behavior in advanced, putatively stable allohexaploid lines from different sources using high throughput genotyping and cytogenetics; 2) enlarge genetic diversity based on existing germplasm and in newly generated lines produced by intercrossing and recombination between diverse Chinese and German germplasm and 3) select and assess agronomic traits in the advanced germplasm using field-based phenotyping and QTL mapping.Results will facilitate the development of a new, high-yielding rapeseed crop species for oil, vegetable and biomass energy production in China, Germany and worldwide.