Architectural and anatomical responses of maize roots to agronomic practices in a semi‐arid environment

Abstract

Root architecture and anatomy are important determinants of nitrogen (N) and water acquisition, but they are also environmentally plastic to adapt to N and water availability. Therefore, understanding the relationship between root traits and environmental factors is essential for improving N and water acquisition. A field experiment was conducted in the semi‐arid region of the Loess Plateau in northwestern China to quantify the architectural and anatomical root traits of maize (Zea mays L.) in response to plastic film mulching and N fertilization. We compared four treatments: non‐mulching with and without N supply as well as plastic film mulching with and without N supply. Variation existed for all root architecture and anatomy traits within maize root crowns. Crown and brace root angles to the soil line decreased in response to film mulching and N fertilization. Crown roots under plastic film mulching showed a significantly decreased distance to branching, reduced lateral root length, and overall increased root diameter. Similarly, N application significantly decreased the distance to branching, yet induced more compact and denser crown roots, and increased the root diameter. Brace roots exhibited an increased distance to branching, greater lateral root length and density, as well as a larger root diameter in response to plastic film mulching and N fertilization. Additionally, the accumulated number of nodal roots increased greatly under plastic film mulching and N treatments. At the anatomical level, N application reduced the proportion of the root cortical aerenchyma area. In contrast, aerenchyma area, cortex cell size, and late metaxylem vessel diameter were increased as a result of plastic film mulching. These results demonstrate root architectural and anatomical traits respond to mulching practices and N fertilization.

Effects of Superhydrophobic Sand Mulching on Evapotranspiration and Phenotypic Responses in Tomatoes (Solanum lycopersicum) under Normal and Reduced Irrigation

“…7 ). Consistent with these findings, larger xylem vessel and root diameters have been shown to develop in wheat plants in response to increased SWC caused by mulching (Zhan et al, 2019), increasing WUE and shoot biomass (Kadam et al, 2015). Although small-diameter roots maintain plant growth during a drought, especially at soil depths with available water (Comas et al, 2013), several researchers have suggested that large-diameter roots are more instrumental in resource uptake and plant growth under water scarcity (Larson and Funk, 2016, Kadam et al, 2015).…”

“…Mulching, i.e., applying a vapor diffusion barrier on the topsoil to curtail water evaporation, has been proven to enhance soil moisture content and provide enhanced transpiration (Moitra, 1996, Zhang et al, 2018, Farzi et al, 2017), plant biomass, and yields (Ramalan, 2000, Zhang, 2017a, Mukherjee, 2010). Mulching has been demonstrated to enhance leaf chlorophyll content (Wang et al, 2015), photosynthesis (Niu et al, 2020, Zhang et al, 2019), and TE (Balwinder-Singh et al, 2011), as well as improve plant root growth and roots’ architectural and anatomical properties, such as root diameter and late xylem vessel diameter, which improves water and nutrient uptake from the soil (Zhan et al, 2019, Larsson and Jensen, 1996). Low-density polyethylene sheets approximately 0.1 mm thick have been used extensively for mulching in developed countries (Kasirajan and Ngouajio, 2012).…”

Rated-M for mesocosm: allowing the multimodal analysis of mature root systems in 3D

“…While intrinsically a small and superficial part of the overall RSA, the crown is the information-dense nexus. Root crown analysis has been effective across a diversity of research topics ranging from the effect of agricultural practices on root growth [20], drought-induced root traits [21], the identification of QTLs [22], and mutant analysis [23]. However, the desire for non-destructive measurements across the entire root system prompted the development of rhizotrons, large subterranean chambers where roots in physical contact with clear walls can be studied, requiring extensive long-term infrastructure [24][25][26][27][28].…”

Multiple brace root phenotypes promote anchorage and limit root lodging in maize

“…To link brace root phenotypes to root lodging resistance and anchorage necessitates a high throughput brace root phenotyping workflow. Current root phenotyping methods are either labor intensive, rely on subjective manual data collection, and/or are not targeted for brace root phenotyping (Trachsel et al, 2011; Das et al, 2015; Zhan et al, 2019; Salungyu et al, 2020, Sanguineti et al, 1998; Liu et al, 2012; Sharma and Carena, 2016). Thus, we developed a workflow that non-destructively captures RGB (Red Green Blue) images using a ground-based robot and extracts brace root phenotypes through a semi-automated root tagging pipeline.…”