Root adaptations to soils with low fertility and aluminium toxicity

Abstract

Background Plants depend on their root systems to acquire the water and nutrients necessary for their survival in nature, and for their yield and nutritional quality in agriculture. Root systems are complex and a variety of root phenes have been identified as contributors to adaptation to soils with low fertility and aluminium (Al) toxicity. Phenotypic characterization of root adaptations to infertile soils is enabling plant breeders to develop improved cultivars that not only yield more, but also contribute to yield stability and nutritional security in the face of climate variability.Scope In this review the adaptive responses of root systems to soils with low fertility and Al toxicity are described. After a brief introduction, the purpose and focus of the review are outlined. This is followed by a description of the adaptive responses of roots to low supply of mineral nutrients [with an emphasis on low availability of nitrogen (N) and phosphorus (P) and on toxic levels of Al]. We describe progress in developing germplasm adapted to soils with low fertility or Al toxicity using selected examples from ongoing breeding programmes on food (maize, common bean) and forage/feed (Brachiaria spp.) crops. A number of root architectural, morphological, anatomical and metabolic phenes contribute to the superior performance and yield on soils with low fertility and Al toxicity. Major advances have been made in identifying root phenes in improving adaptation to low N (maize), low P (common bean) or high Al [maize, common bean, species and hybrids of brachiariagrass, bulbous canarygrass (Phalaris aquatica) and lucerne (Medicago sativa)].Conclusions Advanced root phenotyping tools will allow dissection of root responses into specific root phenes that will aid both conventional and molecular breeders to develop superior cultivars. These new cultivars will play a key role in sustainable intensification of crop–livestock systems, particularly in smallholder systems of the tropics. Development of these new cultivars adapted to soils with low fertility and Al toxicity is needed to improve global food and nutritional security and environmental sustainability.

Intergenerational responses of wheat (Triticum aestivum L.) to cerium oxide nanoparticles exposure

“…22 In contrast to the large reduction of Al, Fe and Mn observed in roots, exposure to CeO 2 -NPs had little influence on element concentrations in wheat shoots. P uptake in S1-Ce-125 was 9% higher whereas K storage in S1-Ce-500 was 7% lower compared to those in unexposed control (data not shown).…”

Breeding Maize for Tolerance to Acidic Soils: A Review

“…Al toxicity limits agricultural productivity by preventing crops to reach their yield potential [36][37][38][39]. Al toxicity (60 to 300 µg per liter of water in soil) can cause 25-80% yield losses in various crop plants [40].…”

Phenotyping roots in darkness: disturbance-free root imaging with near infrared illumination

“…It has also been reported that maize genotypes with few crown roots had greater nitrogen (N) acquisition from low N soils (Saengwilai et al 2014). Root morphological traits such as root length, diameter, surface area and volume, presence of root hairs and length of root hairs contribute to inter-and intra-specific variation in P acquisition efficiency (Rao et al 2016). The adaptive responses of root systems to soils with low fertility have been reviewed by Rao et al (2016).…”

“…Root morphological traits such as root length, diameter, surface area and volume, presence of root hairs and length of root hairs contribute to inter-and intra-specific variation in P acquisition efficiency (Rao et al 2016). The adaptive responses of root systems to soils with low fertility have been reviewed by Rao et al (2016). Pestsova et al (2016) describe the co-location of quantitative trait loci (QTL) for root traits and maize yield although their causal relationship will have to be investigated in more detail.…”