Seed shattering is a key constraint to improvement of seed yield in perennial ryegrass and, as a result, seed retention is an essential trait for breeding of this valuable crop. It is unclear whether sources of seed retention are available to plant breeders. Field studies were conducted near Corvallis, OR in 2 yr (2017–2018 and 2018–2019) to identify genetic variation for seed retention and to ascertain whether there was variation for phenotypic traits that may contribute to seed loss due to shattering. The field studies examined the values and variation in these traits in 40 diverse global accessions and genotypic lines within accessions. Plant mortality was high as only 21 of the original 40 accessions survived in sufficient numbers for analysis. The accessions and genotypic lines exhibited great variation in growth habit, spikelets per spike, seeds per spike, seed weight, spike length, and seed retention. Seed retention among accessions ranged from 27.1 to 78.7% with a commercial cultivar at 42.4% retention. For the most part, the values and variation observed in other characteristics were similar to that found in perennial ryegrass in other investigations, and some materials were representative of commercial cultivars. This study presents evidence that sources of higher seed retention than is found in commercial cultivars of perennial ryegrass is available from these accessions and could be used in the breeding of shatter-resistant cultivars.

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多年生黑麦草 (Lolium perenne L.) 种质和基因型品系中种子保留的遗传变异

种子落粒是提高多年生黑麦草种子产量的关键制约因素，因此，种子保留是育种这种有价值作物的基本特性。目前尚不清楚植物育种者是否可以获得种子保留来源。2 年（2017-2018 年和 2018-2019 年）在俄勒冈州科瓦利斯附近进行了实地研究，以确定种子保留的遗传变异，并确定是否存在可能导致种子因破碎而损失的表型性状变异。实地研究检查了这些性状在 40 个不同的全球种质和种质中的基因型品系中的价值和变异。植物死亡率很高，因为最初的 40 份收集品中只有 21 份以足够的数量存活下来用于分析。种质和基因型品系在生长习性、每穗小穗数、每穗种子数、种子重量、穗长和种子保留率。种质间的种子保留率为 27.1% 至 78.7%，商业品种的保留率为 42.4%。在大多数情况下，在其他特性中观察到的值和变异与在其他调查中在多年生黑麦草中发现的相似，并且一些材料代表了商业品种。这项研究提供的证据表明，与多年生黑麦草的商业栽培品种相比，这些种质可提供更高的种子保留来源，并可用于抗裂栽培品种的育种。在其他特性中观察到的值和变异与在其他调查中在多年生黑麦草中发现的相似，并且一些材料代表了商业品种。这项研究提供的证据表明，与多年生黑麦草的商业栽培品种相比，这些种质可提供更高的种子保留来源，并可用于抗裂栽培品种的育种。在其他特性中观察到的值和变异与在其他调查中在多年生黑麦草中发现的相似，并且一些材料代表了商业品种。这项研究提供的证据表明，与多年生黑麦草的商业栽培品种相比，这些种质可提供更高的种子保留来源，并可用于抗裂栽培品种的育种。