Phenotyping, genome-wide dissection, and prediction of maize root architecture for temperate adaptability.

Abstract

Abstract Root System Architecture (RSA) plays an essential role in influencing maize yield by enhancing anchorage and nutrient uptake. Analyzing maize RSA dynamics holds potential for ideotype‐based breeding and prediction, given the limited understanding of the genetic basis of RSA in maize. Here, we obtained 16 root morphology‐related traits (R‐traits), 7 weight‐related traits (W‐traits), and 108 slice‐related microphenotypic traits (S‐traits) from the meristem, elongation, and mature zones by cross‐sectioning primary, crown, and lateral roots from 316 maize lines. Significant differences were observed in some root traits between tropical/subtropical and temperate lines, such as primary and total root diameters, root lengths, and root area. Additionally, root anatomy data were integrated with genome‐wide association study (GWAS) to elucidate the genetic architecture of complex root traits. GWAS identified 809 genes associated with R‐traits, 261 genes linked to W‐traits, and 2577 key genes related to 108 slice‐related traits. We confirm the function of a candidate gene, fucosyltransferase5 ( FUT5 ), in regulating root development and heat tolerance in maize. The different FUT5 haplotypes found in tropical/subtropical and temperate lines are associated with primary root features and hold promising applications in molecular breeding. Furthermore, we performed machine learning prediction models of RSA using root slice traits, achieving high prediction accuracy. Collectively, our study offers a valuable tool for dissecting the genetic architecture of RSA, along with resources and predictive models beneficial for molecular design breeding and genetic enhancement.

Plant phenotyping relevance

トウモロコシ根系形態を大規模に取得し、根スライス形質に基づく機械学習予測モデルと再利用可能な資源を構築しており、表現型取得・推定が研究の主要部分です。

Code and data availability

The paper's root phenotyping images, phenotypic data, and RNA-seq data are deposited on figshare, and the authors' GWAS analysis pipeline code is publicly available on GitHub, both explicitly stated in the Data Availability Statement.