The ARC Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 200, Australia.
Department of Psychiatry, University of California San Diego, La Jolla, California 92093.
Genetics. 2019 Jan;211(1):317-331. doi: 10.1534/genetics.118.301589. Epub 2018 Nov 16.
The development of model systems requires a detailed assessment of standing genetic variation across natural populations. The Brachypodium species complex has been promoted as a plant model for grass genomics with translation to small grain and biomass crops. To capture the genetic diversity within this species complex, thousands of Brachypodium accessions from around the globe were collected and genotyped by sequencing. Overall, 1897 samples were classified into two diploid or allopolyploid species, and then further grouped into distinct inbred genotypes. A core set of diverse diploid lines was selected for whole genome sequencing and high resolution phenotyping. Genome-wide association studies across simulated seasonal environments was used to identify candidate genes and pathways tied to key life history and agronomic traits under current and future climatic conditions. A total of 8, 22, and 47 QTL were identified for flowering time, early vigor, and energy traits, respectively. The results highlight the genomic structure of the Brachypodium species complex, and the diploid lines provided a resource that allows complex trait dissection within this grass model species.
模型系统的发展需要对自然种群中的遗传变异进行详细评估。短柄草种复合体被推广为草类基因组学的植物模型，可转化为小粒谷物和生物质作物。为了捕捉该种复合体中的遗传多样性，从全球范围内收集了数千个短柄草属植物的材料，并通过测序进行了基因型鉴定。总体而言，有 1897 个样本被分类为两个二倍体或异源多倍体物种，然后进一步分为不同的自交基因型。选择了一组核心的多样化二倍体系进行全基因组测序和高分辨率表型分析。在模拟季节性环境下进行全基因组关联研究，以鉴定与当前和未来气候条件下关键生活史和农艺性状相关的候选基因和途径。分别鉴定到开花时间、早期活力和能量性状的 8、22 和 47 个 QTL。结果突出了短柄草种复合体的基因组结构，并且二倍体系提供了一个资源，可在该草类模式物种内进行复杂性状的剖析。
