Plant breeding has brought about improvements in the herbage yield potential, forage quality and functional traits of perennial ryegrass (Lolium perenne L.). Under conditions of low external inputs, grassland swards based on perennial ryegrass often contain dicotyledonous species (legume and non-legume). Cultivar-specific functional traits such as growth form or phenology affect the competitive ability and yield in mixtures, but the extent to which cultivars with different functional traits affect forage quality in mixtures compared with pure stands is unknown. Therefore, we analysed four perennial ryegrass cultivars, each representing a combination of two functional traits with respect to phenology (early v. late heading) and growth form (upright v. prostrate) on forage quality, in a field experiment over 5 years. Each cultivar was grown in binary-mixtures with Trifolium repens L., as four-species mixtures with Taraxacum officinale L. and Plantago lanceolata L., and as grass monocultures. The effect of functional traits was dominant in the primary growth and persisted in pure stands but not in the mixtures from the third year onwards. Prostrate cultivars allowed the development of a greater proportion of clover and forbs within the mixtures, resulting in increased protein and energy and reduced fibre contents. In mixtures, forage quality was generally higher in the last regrowth. In conclusion, the indirect effects of growth form on forage quality due to modifications of botanical composition were more important than direct effects on forage quality.

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多年生黑麦草品种功能性状对混合林和纯林牧草品质的影响

植物育种带来了多年生黑麦草草本产量潜力、牧草品质和功能性状的改善。黑麦草L.)。在低外部投入的条件下，以多年生黑麦草为基础的草地通常含有双子叶植物（豆科植物和非豆科植物）。品种特有的功能性状如生长形式或物候会影响混合物中的竞争能力和产量，但与纯林相比，具有不同功能性状的品种对混合物中草料品质的影响程度尚不清楚。因此，我们分析了四个多年生黑麦草品种，每个品种代表了关于物候学的两个功能性状的组合（早期v. 晚标题）和生长形式（直立v. 匍匐）关于草料质量，在超过 5 年的田间试验中。每个品种都在二元混合物中生长三叶草L.，作为四种混合物蒲公英土地车前草L.，并作为草单一栽培。功能性状的影响在初生生长中占主导地位，并在纯林中持续存在，但从第三年开始在混合林中不存在。匍匐栽培品种允许在混合物中发展更大比例的三叶草和杂草，从而增加蛋白质和能量并减少纤维含量。在混合物中，最后一次再生时的草料质量通常较高。总之，由于植物成分的改变，生长形式对草料质量的间接影响比对草料质量的直接影响更重要。