Increasing the extractable sugar yield from perennial crops is one strategy to generate renewable fuels such as bio-ethanol. Lolium perenne L. (perennial ryegrass) can contain significant (>30% dry matter) water-soluble sugars in the form of polymeric fructan which is readily extracted, broken down and fermented to bio-ethanol. A population of L. perenne generated from four parents which differed in water-soluble carbohydrate (WSC) content was subjected to multiple rounds of selection and recombination on the basis of early spring WSC content to produce a high WSC, and a low WSC population. A control population was generated by selecting the same number of plants at random. The alleles present at six candidate gene loci were analysed before and after selection and correlated to WSC content. Significant differences in the allele frequency of L. perenne soluble-acid invertase1:4 were observed between the three populations with one haplotype significantly associated with the high WSC C2^S+ population (after three rounds of selection and two rounds of recombination). Moreover, WSC content was also associated with biomass accumulation. Thus, in addition to a 2.84-fold increase in WSC yield, the C2^S+ population also had 1.48-fold more biomass per plant, resulting in 3.9-fold higher WSC yield per plant than the control population.

中文翻译：

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Lolium perenne L.中生物乙醇生产的育种：等位基因变异与高水溶性碳水化合物含量的关联。

提高多年生作物的可提取糖产量是生产生物乙醇等可再生燃料的一种策略。Lolium perenne L.（多年生黑麦草）可以含有大量（>30% 干物质）以聚合果聚糖形式存在的水溶性糖，这种糖很容易提取、分解和发酵成生物乙醇。L. perenne种群将四种水溶性碳水化合物（WSC）含量不同的亲本在早春WSC含量的基础上进行多轮选择和重组，以产生高WSC和低WSC种群。通过随机选择相同数量的植物产生对照种群。在选择前后分析了六个候选基因位点的等位基因，并与 WSC 含量相关。在三个群体之间观察到L. perenne 可溶性酸性转化酶 1:4的等位基因频率存在显着差异，其中一种单倍型与高 WSC C2 ^{S+显着相关}种群（经过三轮选择和两轮重组）。此外，WSC 含量也与生物量积累有关。因此，除了 WSC 产量增加 2.84 倍外，C2 ^S+群体的每株植物生物量也增加了 1.48 倍，导致每株植物的 WSC 产量比对照群体高 3.9 倍。