The multi‐floral oat (Avena sativa L.) inflorescence influences grain size and shape distributions, affecting the physical attributes of grain quality such as plumpness, size, and uniformity. While the grain size and shape distribution has been characterized as multi‐modal, very little is known about the genetic determinants of those distributions and their properties. The goal of this study was to model grain size and shape distribution using a finite mixture distribution approach and propose new distributional traits (i.e., emerging distributional traits) to characterize genotypes. We evaluated 47 oat genotypes in four highly replicated field experiments. Grains of three panicles per plot were individually threshed and scanned. Grain area, length, width, and roundness were obtained from each grain‐based image, while emerging distributional traits were evaluated using a finite mixture distribution approach. Finally, grain size distributions from hand‐threshed panicles (representing the full biological distribution) were compared with the grain size distributions of grains harvested with a combine harvester representing commercial harvest where small grains may be blown out. The heritability of all grain traits was high (0.89–0.94), and trait distributions differed among genotypes. Grain area and length show bi‐ and trimodal distributions, while grain width and roundness are uni‐ and bimodal. Although the full biological distribution of grains differed from the combine‐harvested grains, their genetic correlations were high, suggesting the combine‐harvested distributions can be used as a proxy for full biological distributions. This study proposes a straightforward methodological approach to model grain attributes that can aid in quality evaluations for genetic studies, breeding decisions, and industry characterization.

中文翻译：

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有限混合物分布，用于对基于图像的燕麦籽粒形态的遗传结构进行建模


多花燕麦 （Avena sativa L.） 花序影响谷物大小和形状分布，影响谷物质量的物理属性，例如丰满度、大小和均匀性。虽然晶粒尺寸和形状分布被表征为多峰分布，但对这些分布的遗传决定因素及其特性知之甚少。本研究的目的是使用有限混合分布方法对晶粒尺寸和形状分布进行建模，并提出新的分布性状（即新出现的分布性状）来表征基因型。我们在 4 个高度复制的田间实验中评估了 47 种燕麦基因型。每个地块 3 个穗的谷物单独脱粒并扫描。从每个基于颗粒的图像中获得颗粒面积、长度、宽度和圆度，而使用有限混合分布方法评估新出现的分布特征。最后，将手工脱粒圆锥花序的粒度分布（代表完整的生物分布）与使用联合收割机收获的谷物的粒度分布进行了比较，这些收获机代表了商业收获，其中小颗粒可能会被吹出。所有谷物性状的遗传力都很高 （0.89–0.94），并且性状分布因基因型而异。晶粒面积和长度呈双峰和三峰分布，而晶粒宽度和圆度呈单峰和双峰分布。尽管谷物的完全生物分布与联合收获的谷物不同，但它们的遗传相关性很高，这表明联合收获的分布可以用作完全生物分布的代表。 本研究提出了一种简单的方法来模拟谷物属性，这有助于遗传研究、育种决策和行业特征的质量评估。