Variation analysis of root system development in wheat seedlings using a root phenotyping system

Authors: ADELEKE, EKUNDAYO - Tennessee State University; MILLAS, RENZ - Tennessee State University; MCNEAL, WAYMON - Tennessee State University; Faris, Justin; TAHERI, ALI - Tennessee State University

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2020
Publication Date: 2/8/2020
Citation: Adeleke, E., Millas, R., McNeal, W., Faris, J.D., Taheri, A. 2020. Variation analysis of root system development in wheat seedlings using a root phenotyping system. Agronomy. 10(2):206. https://doi.org/10.3390/agronomy10020206.
DOI: https://doi.org/10.3390/agronomy10020206

Interpretive Summary: The root architecture of plants, which refers to the spatial distribution of the roots in the soil, is vital for proper anchorage, nutrient uptake and storage, interactions with beneficial microbes, and water uptake. In wheat, the root architectural traits that optimize these functions are essential to achieving high grain yields, especially in dry climates. However, because roots lie below the soil surface, they are difficult to study and often get ignored by breeders when selecting new varieties. Here, researchers developed a system to rapidly characterize the root systems of wheat using a 2-D growth pouch system and image-capturing computer software. Analysis of 34 different wheat lines for 19 specific root traits showed differences in root growth and architecture among the lines, and it revealed several lines with highly desirable root architecture. The methods developed in this study for characterizing root architecture can be used to evaluate wheat lines in a high-throughput manner on a cost-effective basis and ultimately to improve the root systems of modern wheat varieties through conventional means.

Technical Abstract: Background and aims Root system architecture is a vital part of the plant that has been shown to vary between species and within species based on response to genotypic and/or environmental influences. The root traits of wheat seedlings is critical for the establishment and evidently linked to plant height and seed yield. However, plant breeders have not efficiently developed the role of RSA in wheat selection due to the difficulty of studying root traits. Methods We set up a root phenotyping platform to characterize RSA in 34 wheat accessions. The phenotyping pipeline consists of the germination paper-based moisture replacement system, image capture units, and root-image processing software. The 34 accessions from two different wheat ploidy levels (hexaploids and tetraploids), were characterized in ten replicates. A total of 19 root traits were quantified from the root architecture generated. Results This pipeline allowed for rapid screening of 340 wheat seedlings within 10days. Also, at least one line from each ploidy (6x and 4x) showed significant differences (P < 0.05) in measured traits except in mean seminal count. Our result also showed strong correlation (0.8) between total root length, maximum depth and convex hull area. Conclusions This phenotyping pipeline has the advantage and capacity to increase screening potential at early stages of plant development leading to characterization of wheat seedling traits that can be further examined using QTL analysis in populations generated from the examined accessions.