Genetic Differentiation in Response to Selection for Water-Soluble Carbohydrate Content in Perennial Ryegrass (Lolium perenne L.)
Genetic Differentiation in Response to Selection for Water-Soluble Carbohydrate Content in Perennial Ryegrass (Lolium perenne L.)
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DOI：
10.1007/s12155-014-9491-z
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发表时间：
2015-03-01
影响因子：
3.6
通讯作者：
Roldan-Ruiz, I.
中科院分区：
文献类型：
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作者：
Gallagher, J. A.;Turner, L. B.;Roldan-Ruiz, I.
植物碳水化合物作为可再生原料在燃料生产和高价值化学品生产中替代石油化学品越来越受到关注。更好地了解果聚糖合成和积累的多样性的遗传控制，将有助于更直接的引导原料在黑麦草生物炼制过程中。水溶性碳水化合物含量的表型选择产生的分歧群体已被用来调查性状之间的关系，并确定遗传分化的模式，这表明基因组区域在高和低的选择压力。高水溶性碳水化合物含量的选择与大果聚糖聚合物的合成增加和地上植物生物量的积累增加，特别是在春季。三轮选择和两轮重组导致了整个基因组的广泛遗传分化，导致等位基因丰富度降低，某些位点的纯合性增加。少数基因座被证明受到高选择压力。经过多年水溶性碳水化合物选择的育种材料也表现出等位基因的差异，这可能反映了在这些相同的基因座中的一些高选择压力的后果。然而，在趋异选择实验中未受影响的一些位点表现出类似的效应。这可能是由于这两组植物材料中连锁不平衡的差异，但更可能是由于种质的遗传背景不同。这说明了多年生黑麦草水溶性碳水化合物性状的复杂性。
Plant carbohydrates are of increasing interest as renewable feedstocks to replace petrochemicals in the generation of fuels and production of high-value chemicals. Greater understanding of the genetic control of diversity in fructan synthesis and accumulation would facilitate more directed channelling of feedstock to process in a ryegrass biorefinery. Divergent populations produced by phenotypic selection for water-soluble carbohydrate content have been used to investigate relationships between traits, and to identify patterns of genetic differentiation which indicate genomic regions under high and low selection pressure. Selection for high water-soluble carbohydrate content was associated with increased synthesis of large fructan polymers and increased accumulation of above-ground plant biomass, particularly during spring. Three rounds of selection and two rounds of recombination resulted in widespread genetic differentiation across the whole genome, causing reduced allelic richness and increasing homozygosity at some loci. A smaller number of loci were shown to be subject to high selection pressure. Breeding material subjected to many years of selection for water-soluble carbohydrate also showed allelic differences which may reflect the consequences of high selection pressure at some of these same loci. However, some of the loci unaffected in the divergent selection experiment showed similar effects. This might arise from differences in linkage disequilibrium in these two sets of plant materials, but more likely from the different genetic background of the germplasm. This illustrates the complex nature of the water-soluble carbohydrate trait in perennial ryegrass.