Competition between Zea mays genotypes with different root morphological and physiological traits is dependent on phosphorus forms and supply patterns

Abstract

Background and Aims Each genotype within species has a particular combination of root morphological and/or physiological traits to adapt to a phosphorus-limited environment, which can lead to its unique plant fitness and competitive ability. Yet, how the various phosphorus environments affect the competition between genotypes remains obscure.Methods Two maize (Zea mays L.) genotypes (XY335 and HMY, bred in nutrient-rich and nutrient-poor environments, respectively) were grown in monoculture and mixture in phosphorus-limited soil with homogeneous or heterogeneous supply patterns and inorganic (P inorg ) or organic phosphorus (P org ) forms. ResultsIn the homogeneous P inorg and P org environments, XY335 had higher root length and surface area, but lower mycorrhizal colonization and the acid phosphatase and phytase activities in the rhizosphere, than HMY. In the heterogeneous phosphorus environments, XY335 had higher root proliferation than HMY. The root trait divergence influenced the competition in the mixture: XY335 had a competitive advantage compared to HMY under heterogeneous phosphorus conditions, whereas HMY exhibited a stronger competitive ability in the homogeneous phosphorus treatments; these reverse trends were more significant in the P org than P inorg treatments. ConclusionsThe results suggested the importance of root physiological traits in homogeneous phosphorus-limited soil environments, whereas P acquisition strategy based on the morphological root traits favours heterogeneous phosphorus supply.

Plant nutrition and soil fertility: synergies for acquiring global green growth and sustainable development

“…It was observed that grain dry weight (DW) yield was positively correlated with shoot N, P and K contents irrespective of soil fertility, and it was concluded that the ability of a genotype to acquire nutrients is a major constraint to grain production in rice. In a complimentary study, Li et al (2018) have studied the consequences of root traits for P acquisition, growth and competition between crop genotypes. They compared the responses of seedlings of two maize genotypes bred in nutrient-rich (Xianyu335; XY335) and nutrient-poor (Huangmaya; HMY) environments to a limited homogeneous or heterogeneous P supply, as inorganic and organic forms, when grown in monoculture and when grown together.…”

Neighbors, Drought, and Nitrogen Application Affect the Root Morphological Plasticity of Dalbergia odorifera

“…To capture more resources, plants can develop RMP to a heterogeneous distribution of nutrients that results from spatiotemporal heterogeneity in a natural soil environment or from resource depletion by neighbors (Mou et al, 1997(Mou et al, , 2012Wang et al, 2018a). The neighbor-induced RMP of a plant is generally estimated from some root-related indices, namely, the root response ratio (RRS) and root relative competition index (RRI; Li et al, 2013Li et al, , 2018. In addition, foraging strategies based on root traits can be used to determine whole competitiveness (Semchenko et al, 2018).…”

“…In addition, foraging strategies based on root traits can be used to determine whole competitiveness (Semchenko et al, 2018). For example, in a mixture of two maize (Zea mays L.) genotypes (XY335 and HMY), the higher RRS (RRS > 0) of XY335 reflected a stronger RMP, which ultimately conferred a stronger competitive advantage on XY335 in a mixture of XY335 and HMY (Li et al, 2018). The majority of related studies also emphasize that plants with greater root proliferation can absorb nutrients more quickly under conditions of heterogeneous nutrients.…”

Shared genetic architecture underlying root metaxylem phenotypes under drought stress in cereals

“…As the primary organ responsible for the sensing and uptake of water, roots have become a focus for crop improvement under drought (Lynch et al, 2014; Vadez, 2014). Recent efforts have sought to approach root-focused breeding by selecting for a root system architecture better adapted to water-limited conditions (Ho et al, 2005; Lynch, 2013; Li et al, 2018; Zhang et al, 2019; Burridge et al, 2020). For instance, a steep root growth angle that increases rooting depth has been associated with improved tolerance to water scarcity in maize (Liakat Ali et al, 2015; Pires et al, 2020) and rice (Uga et al, 2013).…”