PDF(Pubmed)
Abstract：
Cultivated potatoes are incredibly diverse, ranging from diploid to pentaploid and encompass four different species. They are adapted to disparate environments and conditions and carry unique alleles for resistance to pests and pathogens. Describing how diversity is partitioned within and among these populations is essential to understanding the potato genome and effectively utilizing landraces in breeding. This task is complicated by the difficulty of making comparisons across cytotypes and extensive admixture within section petota. We genotyped 730 accessions from the US Potato genebank including wild diploids and cultivated diploids and tetraploids using Genotype-by-sequencing. This data set allowed us to interrogate population structure and diversity as well as generate core subsets which will support breeders in efficiently screening genebank material for biotic and abiotic stress resistance alleles. We found that even controlling for ploidy, tetraploid material exhibited higher observed and expected heterozygosity than diploid accessions. In particular group chilotanum material was the most heterozygous and the only taxa not to exhibit any inbreeding. This may in part be because group chilotanum has a history of introgression not just from wild species, but landraces as well. All group chilotanum, exhibits introgression from group andigenum except clones from Southern South America near its origin, where the two groups are not highly differentiated. Moving north, we do not observe evidence for the same level of admixture back into group andigenum. This suggests that extensive history of admixture is a particular characteristic of chilotanum.
摘要：
栽培的土豆非常多样化，从二倍体到五倍体，涵盖四个不同的物种。它们适应不同的环境和条件，并携带独特的等位基因以抵抗害虫和病原体。描述多样性如何在这些种群内部和之间分配对于理解马铃薯基因组和有效利用地方品种进行育种至关重要。由于难以在petota节内的细胞类型和大量混合物之间进行比较，因此这项任务变得复杂。我们通过测序对来自美国马铃薯基因库的730个种质进行了基因分型，包括野生二倍体，栽培二倍体和四倍体。该数据集使我们能够询问种群结构和多样性，并生成核心子集，这将支持育种者有效地筛选基因库材料中的生物和非生物胁迫抗性等位基因。我们发现即使控制倍性，四倍体材料比二倍体材料表现出更高的观察和预期杂合性。特别是，一组chilotanum材料是最杂合的，并且是唯一不表现出任何近亲繁殖的类群。这可能部分是因为一组chilotanum具有渗入的历史，不仅来自野生物种，但地方品种也是如此。所有组chilotanum,除了来自南美南部附近的克隆外，还表现出来自Anigenum组的渗入，两组没有高度分化。向北移动，我们没有观察到相同水平的混合物回到组的证据。这表明混合物的广泛历史是chilotanum的特殊特征。
