The James Hutton Institute, Invergowrie, Dundee, UK.
School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
Ann Bot. 2020 Jul 24;126(2):289-300. doi: 10.1093/aob/mcaa079.
Manganese (Mn) deficiency in barley is a global problem. It is difficult to detect in the early stages of symptom development and is commonly pre-emptively corrected by Mn foliar sprays that can be costly. Landraces adapted to marginal lands around the world represent a genetic resource for potential sustainability traits including mineral use efficiency. This research aims to confirm novel Mn use efficiency traits from the Scottish landrace Bere and use an association mapping approach to identify genetic loci associated with the trait.
A hydroponic system was developed to identify and characterize the Mn deficiency tolerance traits in a collection of landraces, including a large number of Scottish Bere barleys, a group of six-rowed heritage landraces grown in the highlands and islands of Scotland. Measuring chlorophyll fluorescence, the effect of Mn deficiency was identified in the early stages of development. Genotypic data, generated using the 50k Illumina iSelect genotyping array, were coupled with the Mn phenotypic data to create a genome-wide association study (GWAS) identifying candidate loci associated with Mn use efficiency.
The Bere lines generally had good Mn use efficiency traits. Individual Bere lines showed large efficiencies, with some Bere lines recording almost double chlorophyll fluorescence readings in limited Mn conditions compared with the elite cultivar Scholar. The Mn-efficient Bere lines had increased accumulation of Mn in their shoot biomass compared with elite cultivars, which was highly correlated to the chlorophyll fluorescence. Several candidate genes were identified as being associated with Mn use efficiency in the GWAS.
Several genomic regions for Mn use efficiency traits originating from the Bere lines were identified. Further examination and validation of these regions should be undertaken to identify candidate genes for future breeding for marginal lands.
大麦缺锰是一个全球性问题。在症状出现的早期阶段很难检测到，通常可以通过叶面喷施锰来预防，但这可能会很昂贵。世界各地适应边缘土地的地方品种代表了一种遗传资源，具有包括矿物利用效率在内的潜在可持续性特征。本研究旨在确认来自苏格兰地方品种 Bere 的新型锰利用效率特性，并使用关联图谱方法来鉴定与该特性相关的遗传基因座。
开发了一种水培系统，以鉴定和表征包括大量苏格兰 Bere 大麦在内的地方品种群体对锰缺乏的耐受特性，其中还包括在苏格兰高地和岛屿种植的一组六棱地方品种。通过测量叶绿素荧光，可以在发育的早期阶段识别出锰缺乏的影响。使用 Illumina iSelect 50k 基因分型阵列生成的基因型数据与锰表型数据相结合，进行全基因组关联研究（GWAS），确定与锰利用效率相关的候选基因座。
Bere 系通常具有良好的锰利用效率特性。个别 Bere 系表现出较高的效率，与精英品种 Scholar 相比，一些 Bere 系在有限的锰条件下记录的叶绿素荧光读数几乎高出一倍。与精英品种相比，锰高效 Bere 系的地上生物量中锰的积累量增加，这与叶绿素荧光高度相关。在 GWAS 中，确定了几个与锰利用效率相关的候选基因。
从 Bere 系中鉴定出了几个与锰利用效率性状相关的基因组区域。应进一步检查和验证这些区域，以鉴定未来用于边缘土地的育种的候选基因。
