Root Architecture and Functional Traits of Spring Wheat Under Contrasting Water Regimes

Abstract

Wheat roots are known to play an important role in the yield performance under water-limited (WL) conditions. Three consecutive year trials (2015, 2016, and 2017) were conducted in a glasshouse in 160 cm length tubes on a set of spring wheat ( Triticum aestivum L.) genotypes under contrasting water regimes (1) to assess genotypic variability in root weight density (RWD) distribution in the soil profile, biomass partitioning, and total water used; and (2) to determine the oxygen and hydrogen isotopic signatures of plant and soil water in order to evaluate the contribution of shallow and deep soil water to plant water uptake and the evaporative enrichment of these isotopes in the leaf as a surrogate for plant transpiration. In the 2015 trial under well-watered (WW) conditions, the aerial biomass (AB) was not significantly different among 15 wheat genotypes, while the total root biomass and the RWD distribution in the soil profile were significantly different. In the 2016 and 2017 trials, a subset of five genotypes from the 2015 trial was grown under WW and WL regimes. The water deficit significantly reduced AB only in 2016. The water regimes did not significantly affect the root biomass and root biomass distribution in the soil depths for both the 2016 and 2017 trials. The study results highlighted that under a WL regime, the production of thinner roots with low biomass is more beneficial for increasing the water uptake than the production of large thick roots. The models applied to estimate the relative contribution of the plant’s primary water sources (shallow or deep soil water) showed large interindividual variability in soil, and plant water isotopic composition resulted in large uncertainties in the model estimates. On the other side, the combined information of root architecture and the leaf stable isotope signatures could explain plant water status.

Variation in Root-Related Traits Is Associated With Water Uptake in Lagenaria siceraria Genotypes Under Water-Deficit Conditions

“…Based on this idea, this study examined the root morphology of eight L. siceraria genotypes and investigated the various root traits at different substrate depths and root diameter intervals under a water-deficit condition. For instance, different root-related traits, such as primary root length, number and length of lateral roots, and average root diameter, have been proposed as important traits that contribute to regulating water uptake, which is critical under drought stress (Gorim and Vandenberg, 2017 ; Mwenye et al, 2018 ; Brunel-Saldias et al, 2020 ; Gao et al, 2020 ). In this study, a statistically significant effect of water deficit was reported over all the evaluated root traits.…”

“…For example, Gorim and Vandenberg ( 2017 ) pointed out that, between depths of 40–60 cm, lentil genotypes with higher total root length (TRL) proportions of very fine roots (<0.5 mm) were able to exploit both water and nutrients more efficiently; while between depths of 0–20 and 20–40 cm, lentil genotypes with TRL diameters >2.0 mm were more efficient in the long-distance transportation of water and nutrients. Similarly, Brunel-Saldias et al ( 2020 ) showed that, under a water-limited regime, water use (WU) in spring wheat was positively related to root weight density at different soil layers. Thus, while root traits such as length, diameter, area, and volume are important, more information about root systems can be gained by looking at root distribution patterns at various soil depths.…”

“…The ability of plant roots to capture water and nutrients from different depths in the soil profile is related to phenotypic variation and plasticity in root system traits, such as root length, diameter, area, and volume (Gorim and Vandenberg, 2017 ; Brunel-Saldias et al, 2020 ). For example, Gorim and Vandenberg ( 2017 ) pointed out that, between depths of 40–60 cm, lentil genotypes with higher total root length (TRL) proportions of very fine roots (<0.5 mm) were able to exploit both water and nutrients more efficiently; while between depths of 0–20 and 20–40 cm, lentil genotypes with TRL diameters >2.0 mm were more efficient in the long-distance transportation of water and nutrients.…”

A Comprehensive Review on Chickpea (Cicer arietinum L.) Breeding for Abiotic Stress Tolerance and Climate Change Resilience

“…In the future, the selection of new cultivars should be based on a complete phenotypic and genetic description of the materials to be used as parental material in breeding programs. This can be based on new high-throughput phenotyping techniques [ 163 ], such as the characterization of plant canopy temperature and root system architecture in heat and drought stress experiments [ 164 ]. The whole genetic characterization of parent material should be one of the cornerstones in the future.…”

Effect of Combined Dressing Agents on Phytosanitary Situation in Winter Wheat Ecosystems

“…Among many factors that reduce the efficiency of grain production, overlooking an arsenal of phytophages and phytopathogens developing, which significantly hampers yield growth, subject to specific natural and climatic conditions and closely related crop production processes, is fatal. A more flexible approach in framing the strategy, feasibility and agenda of measures to protect crops will not only increase the yield of winter wheat, but also reduce the environmental risks associated with an unwarranted use of pesticides [3][4][5][6].…”