Recreating genomically stable rapeseed

甘蓝型油菜（Brassica napus）是高度近交的作物物种，缺乏持续农业改良所需的大量遗传多样性。为了增加油菜的遗传多样性，一种常用的方法是通过在油菜祖先种B之间制造新的杂交种来重建该种。rapa和B.橄榄科。这些新的杂种具有与B相同的染色体组成。以及增加遗传多样性。然而，这些杂种也具有不稳定的基因组，由于减数分裂控制不良，并失去染色体，因此，植物生长和生育力的重要遗传信息，从一代到一代。这种基因组不稳定性的原因是未知的，特别是因为天然B。甘蓝型油菜基因组稳定。我们认为，有两种可能的假设，这种不稳定性在新的杂交。首先，这种不稳定性可能是由于每个祖先物种内的等位基因变异，即基因组稳定性的基因型差异，使得正确的遗传变体尚未在人类介导的杂交事件中组合以产生稳定的合成油菜籽。其次，突变可能发生在B之后不久。油菜形成了加强基因组稳定性。我们的目的是测试这些假设，通过调查基因组稳定性在一个大的一组（292行）的人工杂交油菜。将使用高通量标记基因分型来量化基因组重排，并评估生育力和减数分裂行为，以确定哪些品系显示稳定和不稳定的表型。鉴定B中基因组稳定性的机制。欧洲油菜不仅将为了解该物种的进化历史提供令人着迷的见解，而且将立即有助于提供信息和协助将有用的遗传多样性转移到油菜籽中。

Rapeseed (Brassica napus) is a highly inbred crop species, lacking the substantial genetic diversity required for continuing agricultural improvement. In order to increase genetic diversity in rapeseed, a common method is to recreate this species by making new hybrids between rapeseed progenitor species B. rapa and B. olereacea. These new hybrids have the same chromosome composition as B. napus, as well as increased genetic diversity. However, these hybrids also have unstable genomes due to poor control of meiosis, and lose chromosomes, and hence essential genetic information for plant growth and fertility, from generation to generation. The reason for this genome instability is unknown, particularly since natural B. napus is genomically stable. We suggest that there are two possible hypotheses for this instability in new hybrids. Firstly, this instability could be due to allelic variation within each progenitor species, i.e. genotypic differences in genomic stability, such that the right genetic variants have yet to be combined in human-mediated hybridisation events to produce stable synthetic rapeseed. Secondly, a mutation may have occurred shortly after B. napus formed that enforced genomic stability. We aim to test these hypotheses by investigating genomic stability in a large set (292 lines) of human-made hybrid rapeseed. High-throughput marker genotyping will be used to quantify genomic rearrangements, and fertility and meiotic behavior will be assessed to determine which lines show stable and unstable phenotypes. Identification of the mechanism/s of genomic stability in B. napus will not only provide fascinating insights into the evolutionary history of this species, but will be immediately useful for informing and assisting in transfer of useful genetic diversity into rapeseed.