Melchinger Albrecht E, Schopp Pascal, Müller Dominik, Schrag Tobias A, Bauer Eva, Unterseer Sandra, Homann Linda, Schipprack Wolfgang, Schön Chris-Carolin
Institute of Plant Breeding, Seed Science and Population Genetics, University of Hohenheim, 70593 Stuttgart, Germany
Institute of Plant Breeding, Seed Science and Population Genetics, University of Hohenheim, 70593 Stuttgart, Germany.
Genetics. 2017 Jul;206(3):1611-1619. doi: 10.1534/genetics.115.186205. Epub 2017 May 3.
Thousands of landraces are stored in seed banks as "gold reserves" for future use in plant breeding. In many crops, their utilization is hampered because they represent heterogeneous populations of heterozygous genotypes, which harbor a high genetic load. We show, with high-density genotyping in five landraces of maize, that libraries of doubled-haploid (DH) lines capture the allelic diversity of genetic resources in an unbiased way. By comparing allelic differentiation between heterozygous plants from the original landraces and 266 derived DH lines, we find conclusive evidence that, in the DH production process, sampling of alleles is random across the entire allele frequency spectrum, and purging of landraces from their genetic load does not act on specific genomic regions. Based on overall process efficiency, we show that generating DH lines is feasible for genetic material that has never been selected for inbreeding tolerance. We conclude that libraries of DH lines will make genetic resources accessible to crop improvement by linking molecular inventories of seed banks with meaningful phenotypes.
数千个地方品种作为“黄金储备”保存在种子库中，以备将来用于植物育种。在许多作物中，它们的利用受到阻碍，因为它们代表了杂合基因型的异质群体，具有很高的遗传负荷。我们通过对五个玉米地方品种进行高密度基因分型表明，双单倍体（DH）系文库以无偏的方式捕获了遗传资源的等位基因多样性。通过比较原始地方品种的杂合植株与266个衍生DH系之间的等位基因分化，我们找到了确凿的证据，即在DH生产过程中，等位基因的抽样在整个等位基因频率谱上是随机的，并且从地方品种中清除其遗传负荷不会作用于特定的基因组区域。基于整体过程效率，我们表明，对于从未因耐自交而被选择的遗传材料，生成DH系是可行的。我们得出结论，DH系文库将通过将种子库的分子清单与有意义的表型联系起来，使遗传资源可用于作物改良。
