An Automated Image Analysis Pipeline Enables Genetic Studies of Shoot and Root Morphology in Carrot ( Daucus carota L.).

Abstract

Carrot is a globally important crop, yet efficient and accurate methods for quantifying its most important agronomic traits are lacking. To address this problem, we developed an automated image analysis platform that extracts components of size and shape for carrot shoots and roots, which are necessary to advance carrot breeding and genetics. This method reliably measured variation in shoot size and shape, petiole number, petiole length, and petiole width as evidenced by high correlations with hundreds of manual measurements. Similarly, root length and biomass were accurately measured from the images. This platform also quantified shoot and root shapes in terms of principal components, which do not have traditional, manually measurable equivalents. We applied the pipeline in a study of a six-parent diallel population and an F 2 mapping population consisting of 316 individuals. We found high levels of repeatability within a growing environment, with low to moderate repeatability across environments. We also observed co-localization of quantitative trait loci for shoot and root characteristics on chromosomes 1, 2, and 7, suggesting these traits are controlled by genetic linkage and/or pleiotropy. By increasing the number of individuals and phenotypes that can be reliably quantified, the development of a rapid, automated image analysis pipeline to measure carrot shoot and root morphology will expand the scope and scale of breeding and genetic studies.

Plant phenotyping relevance

ニンジンのシュート・根の形態を画像から自動抽出する解析プラットフォームを開発し、手動測定との相関や反復性を検証しており、表現型取得手法が研究の中心である。

Code and data availability

The paper's data availability statement explicitly deposits the authors' analysis scripts on GitHub and the carrot images plus unfiltered F2 SNP calls on FigShare, both with public URLs.