Genomic prediction of yield and root development in wheat under changing water availability

Abstract

Background: Deeper roots help plants take up available resources in deep soil ensuring better growth and higher yields under conditions of drought. A large-scale semi-field root phenotyping facility was developed to allow a water availability gradient and detect potential interaction of genotype by water availability gradient. Genotyped winter wheat lines were grown as rows in four beds of this facility, where indirect genetic effects from neighbors could be important to trait variation. The objective was to explore the possibility of genomic prediction for grain-related traits and deep root traits collected via images taken in a minirhizotron tube under each row of winter wheat measured. Results: The analysis comprised four grain-related traits: grain yield, thousand-kernel weight, protein concentration, and total nitrogen content measured on each half row that were harvested separately. Two root traits, total root length between 1.2 and 2 m depth and root length in four intervals on each tube were also analyzed. Two sets of models with or without the effects of neighbors from both sides of each row were applied. No interaction between genotypes and changing water availability were detected for any trait. Estimated genomic heritabilities ranged from 0.263 to 0.680 for grain-related traits and from 0.030 to 0.055 for root traits. The coefficients of genetic variation were similar for grain-related and root traits. The prediction accuracy of breeding values ranged from 0.440 to 0.598 for grain-related traits and from 0.264 to 0.334 for root traits. Including neighbor effects in the model generally increased the estimated genomic heritabilities and accuracy of predicted breeding values for grain yield and nitrogen content. Conclusions: Similar relative amounts of additive genetic variance were found for both yield traits and root traits but no interaction between genotypes and water availability were detected. It is possible to obtain accurate genomic prediction of breeding values for grain-related traits and reasonably accurate predicted breeding values for deep root traits using records from the semi-field facility. Including neighbor effects increased the estimated additive genetic variance of grain-related traits and accuracy of predicting breeding values. High prediction accuracy can be obtained although heritability is low.

The effect of tillage depth and traffic management on soil properties and root development during two growth stages of winter wheat (Triticum aestivum L.)

“…S3). Moreover, the large environmental variance (low r number) in root relationships may have been caused by spatial effects reported in previous studies ( Guo et al, 2020;Zhou et al, 2021). Compared to traditional 2D…”

A low-cost greenhouse-based high-throughput phenotyping platform for genetic studies: a case study in maize under inoculation with plant growth-promoting bacteria

“…This might be because both managements were tested under nitrogen-limited conditions or the experiment only covered the early developmental stages. For example, Guo et al (2020) reported that low nutrients in optimal irrigated growth conditions might contribute to the absence of genotype-by-water availability interaction in wheat. On the other hand, the significant management effect suggests that PGPB can promote plant growth.…”

The interaction between wheat roots and soil pores in structured field soil

“…The deep rooting characteristics of wheat are important traits that impact nutrient and water acquisition from the subsoil ( Atkinson et al , 2019 ; Bai et al , 2019 ; Guo et al , 2020 ). However, Guo et al (2020) report that low heritability in deep rooting was caused by very large environmental variance due to spatial effects and measurement errors. It is therefore important to understand how environmental factors contribute to variability in root depth.…”

“…Given the large environmental impact of soil on rooting depth, deterorating soil conditions arising from contemporary agriculture might well explain poor rooting, as suggested by White et al (2015) . It is of concern that Guo et al (2020) observed that in a selction of 84 wheats from high-yielding northern and central European varieties and advanced breeding lines, the heritability of deep rooting was low. This was partly attributed to high environmental variability including heterogeneity in soil type which can often be considerable.…”