Plant Genome Mapping Laboratory, University of Georgia, 111 Riverbend Road, Rm 228, Athens, GA 30602, USA.
Theor Appl Genet. 2012 May;124(7):1325-38. doi: 10.1007/s00122-012-1790-1. Epub 2012 Jan 25.
We present SSR-based genetic maps from a cross between Miscanthus sacchariflorus Robustus and M. sinensis, the progenitors of the promising cellulosic biofuel feedstock Miscanthus × giganteus. cDNA-derived SSR markers were mapped by the two-way pseudo-testcross model due to the high heterozygosity of each parental species. A total of 261 loci were mapped in M. sacchariflorus, spanning 40 linkage groups and 1,998.8 cM, covering an estimated 72.7% of the genome. For M. sinensis, a total of 303 loci were mapped, forming 23 linkage groups and 2,238.3 cM, covering 84.9% of the genome. The use of cDNA-derived SSR loci permitted alignment of the Miscanthus linkage groups to the sorghum chromosomes, revealing a whole genome duplication affecting the Miscanthus lineage after the divergence of subtribes Sorghinae and Saccharinae, as well as traces of the pan-cereal whole genome duplication. While the present maps provide for many early research needs in this emerging crop, additional markers are also needed to improve map density and to further characterize the structural changes of the Miscanthus genome since its divergence from sorghum and Saccharum.
我们展示了来自甜象草和芒草杂交种的基于 SSR 的遗传图谱，芒草是有前途的纤维素生物燃料原料芒属 × 巨芒的祖先。由于每个亲本物种的高度杂合性，使用双向拟测交模型对 cDNA 衍生的 SSR 标记进行了映射。总共在甜象草中映射了 261 个位点，跨越 40 个连锁群和 1998.8 cM，估计覆盖了基因组的 72.7%。对于芒草，总共映射了 303 个位点，形成 23 个连锁群和 2238.3 cM，覆盖了基因组的 84.9%。使用 cDNA 衍生的 SSR 位点可以将芒属的连锁群与高粱染色体进行比对，揭示了一个全基因组加倍事件，该事件发生在 Sorghinae 和 Saccharinae 亚族分化之后，影响了芒属谱系，同时也有泛谷物全基因组加倍的痕迹。虽然这些图谱为这个新兴作物的许多早期研究需求提供了依据，但还需要额外的标记来提高图谱密度，并进一步描述芒属从高粱和甘蔗分化以来其基因组结构的变化。
