Characterization of root traits for improvement of spring wheat in the Pacific Northwest

Abstract

Understanding the genetic basis of root traits provides essential information on a largely untapped resource for crop improvement, as roots are instrumental for the uptake of water and nutrients. However, breeding for improved root traits is challenging due to laborious and time‐consuming root phenotyping in soil. Our studies sought to uncover spatiotemporal root‐growth dynamics of mature plant root systems in five spring wheat (Triticum aestivum L.) cultivars, Louise, Alpowa, Hollis, Drysdale, and Dharwar Dry, and a facultative spring landrace, AUS28451 using the in situ minirhizotron technique. The 2‐yr greenhouse study revealed that the root system grows rapidly after early node elongation to gain maximum size during anthesis, after which root growth slows and transitions to senescence. We were able to detect quantifiable differences among wheat cultivars in root traits in both 5‐d old seedlings and root systems at anthesis. Furthermore, the positive correlation of the observed root traits with grain yield and the consistency in root traits observed using minirhizotrons and through extraction of young and mature root systems has reinforced the experimental results. A negative correlation was found between root number, area, and length and root diameter. We found that the spring wheat cultivars, AUS28451, Dharwar Dry, and Alpowa, had increased root number, area, and length, but also increased time to heading. The results from this study can be further leveraged to screen breeding lines for root traits of interest, as well as assess the heritability of root traits for dryland farming in the inland Pacific Northwest.

Fusarium Head Blight and Rust Diseases in Soft Red Winter Wheat in the Southeast United States: State of the Art, Challenges and Future Perspective for Breeding

“…Among the five major wheat classes in the US, soft red winter wheat (SRWW) common to the southeast US shares 15-20% of total area and 17% of total production (Vocke and Ali, 2013). However, this major cereal crop is under continuous threat due to several biotic and abiotic constraints resulting in a significant reduction in grain yield and quality (Limbalkar et al, 2018;Ghimire et al, 2020). Savary et al (2019) reported 31 pests responsible for an estimated 21.5% economic yield loss in wheat.…”

Genetic Variation for Traits Related to Phosphorus Use Efficiency in Lens Species at the Seedling Stage

“…It can be attributed to the correlation between RDW and different root traits, which resulted in efficient P uptake in these genotypes. The increased root length was responsible for higher P uptake from low P supply in barley and sugar beet roots [49,50] whereas the TRT, RSA, TRL and root hair length were important in P uptake in other studies [51,52]. In rice, the genotypic variation in P uptake was due to the RDW and RSA under P deficiency [53].…”

Drought Tolerance Strategies and Autophagy in Resilient Wheat Genotypes

“…Under normal watering, Hollis and Drysdale flowered at the same time, whereas under drought, Hollis flowered earlier than Drysdale ( Figure 1 A). Previous measurements in smaller bins under normal watering showed earlier flowering for Hollis [ 124 ].…”

“…Week 5 and 6 were right before or immediately after flowering. Later stages were not analyzed as wheat roots cease growth past the flowering stage [ 124 ]. Root images were used to measure total root length, total root count, total root volume, total root area, and root diameter.…”

“…Second, vegetative growth was reduced in Hollis, as is evident from the reduced size of the root system and lower tiller number, which were greater in Drysdale. A longer time to heading was correlated with increased root proliferation, which could explain the smaller root system in Hollis than in Drysdale [ 124 ]. Third, Hollis had higher yield per spike than Drysdale.…”