Comprehensive 3D phenotyping reveals continuous morphological variation across genetically diverse sorghum inflorescences

Abstract

Summary Inflorescence architecture in plants is often complex and challenging to quantify, particularly for inflorescences of cereal grasses. Methods for capturing inflorescence architecture and for analyzing the resulting data are limited to a few easily captured parameters that may miss the rich underlying diversity. Here, we apply X‐ray computed tomography combined with detailed morphometrics, offering new imaging and computational tools to analyze three‐dimensional inflorescence architecture. To show the power of this approach, we focus on the panicles of Sorghum bicolor , which vary extensively in numbers, lengths, and angles of primary branches, as well as the three‐dimensional shape, size, and distribution of the seed. We imaged and comprehensively evaluated the panicle morphology of 55 sorghum accessions that represent the five botanical races in the most common classification system of the species, defined by genetic data. We used our data to determine the reliability of the morphological characters for assigning specimens to race and found that seed features were particularly informative. However, the extensive overlap between botanical races in multivariate trait space indicates that the phenotypic range of each group extends well beyond its overall genetic background, indicating unexpectedly weak correlation between morphology, genetic identity, and domestication history.

Plant phenotyping relevance

X線CTと詳細な形態計測を組み合わせ、ソルガム穂の3次元形態を取得・解析する画像ベース表現型手法が研究の中心であるため。

Code and data availability

The paper explicitly states that the full 3D X-ray imaging dataset of sorghum panicles is publicly downloadable from the Topp lab resources page, and that all image processing, feature extraction, and statistical analysis code is available in a public GitHub repository (Topp-Roots-Lab/3D-Sorghum-Inflorescence). Both UR