Pearl millet genotype impacts microbial diversity and enzymatic activities in relation to root-adhering soil aggregation

Abstract

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Root Morphology, Allometric Relations and Rhizosheath of Ancient and Modern Tetraploid Wheats (Triticum durum Desf.) in Response to Inoculation with Trichoderma harzianum T-22

“…Since it is related to exudates produced by roots and associated microflora, and given its key role in root physiology, the rhizosheath may be considered as a plant-related trait [20]. It is affected by plant species [23,24] and variety [19,25]. In wheat varietal differences have been shown [19] but the production of rhizosheath in ancient wheats has not been investigated yet.…”

Genetic control of rhizosheath formation in pearl millet

“…In previous studies, we reported a remarkable genotypic variability for root-adhering soil aggregation in pearl millet 33 . Moreover, this variability was associated with changes in rhizosphere microbiota structure and function 33 , 34 .…”

“…In previous studies, we reported a remarkable genotypic variability for root-adhering soil aggregation in pearl millet 33 . Moreover, this variability was associated with changes in rhizosphere microbiota structure and function 33 , 34 . Here, we analysed the relative contribution of root architectural characteristics and root colonization by AMF on root-adhering soil aggregation in pearl millet.…”

Root traits for low input agroecosystems in Africa: Lessons from three case studies

“…M. S. Ndour et al, 2021) even if it seems to be under complex genetic control in pearl millet (de la Fuente Canto et al, submitted). As rhizosheath formation is positively correlated with root hair length in wheat and barley, QTLs increasing root hair length and/or density to improve P capture could also indirectly improve rhizosheath formation (Delhaize et al, 2015;George et al, 2014).…”

“…First described in desert grasses, rhizosheath formation has since been reported in many cereal crops including sorghum and pearl millet (Brown et al, 2017; Duell & Peacock, 1985⁠; P. M. S. Ndour et al, 2017)⁠.⁠⁠ A positive impact of the rhizosheath on water and mineral nutrition was reported for several plants in laboratory conditions and could be partly explained by improved contact between the soil and the root surface (P. M. S. Ndour et al, 2020)⁠⁠. Phenotyping for rhizosheath size is high throughput and this trait is largely under plant genetic control and large variability exists in the germplasm in pearl millet thus making it a potential target for breeding (P. M. S. Ndour et al, 2021)⁠ even if it seems to be under complex genetic control in pearl millet (de la Fuente Canto et al, submitted)⁠. As rhizosheath formation is positively correlated with root hair length in wheat and barley, QTLs increasing root hair length and/or density to improve P capture could also indirectly improve rhizosheath formation (Delhaize et al, 2015; George et al, 2014)⁠.⁠ However, rhizosheath formation could represent a significant carbon sink, and further work is needed to demonstrate the impact of a larger rhizosheath on dryland cereals in West African field conditions.…”