Root phenotypic plasticity: agronomic, breeding and modelling implications

Zhao, Dongxue; de Voil, Peter; Sadras, Victor; Palta, Jairo; Rodriguez, Daniel

doi:10.21203/rs.3.rs-4120028/v1

Cited by 3 publications

(2 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, a field-based method based on electro-magnetic induction (EMI) sensors (DualEM 21S) was proposed to screen for changes in soil water at different depths to indirectly characterize root systems at depth ( Zhao et al., 2022 ). This non-destructive method was successfully applied to investigate differences between sorghum hybrids ( Zhao et al., 2023 ; Zhao et al., 2024 ) and could potentially be extended to investigate root plasticity to water stress and to identify underlying genetic controls in different crops including wheat.…”

Section: Discussionmentioning

confidence: 99%

Does late water deficit induce root growth or senescence in wheat?

Shazadi,

Christopher,

Chenu

2024

Front. Plant Sci.

View full text Add to dashboard Cite

In crops like wheat, terminal drought is one of the principal stress factors limiting productivity in rain-fed systems. However, little is known about root development after heading, when water uptake can be critical to wheat crops. The impact of water-stress on root growth was investigated in two wheat cultivars, Scout and Mace, under well-watered and post-anthesis water stress in three experiments. Plants were grown outside in 1.5-m long pots at a density similar to local recommended farming practice. Differences in root development were observed between genotypes, especially for water stress conditions under which Scout developed and maintained a larger root system than Mace. While under well-watered conditions both genotypes had shallow roots that appeared to senesce after heading, a moderate water stress stimulated shallow-root growth in Scout but accelerated senescence in Mace. For deep roots, post-heading biomass growth was observed for both genotypes in well-watered conditions, while under moderate water stress, only Scout maintained net growth as Mace deep roots senesced. Water stress of severe intensity affected both genotypes similarly, with root senescence at all depths. Senescence was also observed above ground. Under well-watered conditions, Scout retained leaf greenness (i.e. stay-green phenotype) for slightly longer than Mace. The difference between genotypes accentuated under moderate water stress, with rapid post-anthesis leaf senescence in Mace while Scout leaf greenness was affected little if at all by the stress. As an overall result, grain biomass per plant (‘yield’) was similar in the two genotypes under well-watered conditions, but more affected by a moderate stress in Mace than Scout. The findings from this study will assist improvement in modelling root systems of crop models, development of relevant phenotyping methods and selection of cultivars with better adaptation to drought.

show abstract

Section: Discussionmentioning

confidence: 99%

Does late water deficit induce root growth or senescence in wheat?

Shazadi,

Christopher,

Chenu

2024

Front. Plant Sci.

View full text Add to dashboard Cite

show abstract

“…Recently, a field-based method based on electro-magnetic induction (EMI) sensors (DualEM 21S) was proposed to screen for changes in soil water at different depths to indirectly characterize root systems at depth (Zhao et al, 2022). This non-destructive method was successfully applied to investigate differences between sorghum hybrids (Zhao et al, 2023;Zhao et al, 2024) and could potentially be extended to investigate root plasticity to water stress and to identify underlying genetic controls in different crops including wheat.…”

Section: Implication For Plant Breedingmentioning

confidence: 99%

DataSheet_1.docx

View full text Add to dashboard Cite

Sowing summer grain crops early in late winter or spring: effects on root growth, water use, and yield

Zhao,

deVoil,

Rognoni

et al. 2024

Plant Soil

View full text Add to dashboard Cite

Context Drought and extreme heat at flowering are common stresses limiting the yield of summer crops. Adaptation to these stresses could be increased by sowing summer crops early in late winter or early spring, to avoid overlap of drought and heat with critical crop stages around flowering. Though little is known about the effects of cold weather on root growth, water use and final grain yield in sorghum. Objective This study aims to explore the effects of cold conditions in early sowing sorghum on crop and root growth and function (i.e., water use), and final grain yield. Methods Two years of field experiments were conducted in the Darling and Eastern Downs region of Qld, Australia. Each trial consisted of three times of sowing (late winter, spring, and summer), two levels of irrigation (i.e., rainfed and supplementary irrigated), four plant population densities (3, 6, 9 and 12 pl m−2), and six commercial sorghum hybrids. Roots and shoots were sampled at the flag leaf stage on three times of sowing, two levels of irrigation, and three replications, for a single hybrid and a single plant population density (9 pl m−2). Crop water use and functional root traits were derived from consecutive electromagnetic induction (EMI) surveys around flowering. At maturity crop biomass, yield and yield components were determined across all treatments. Results The combinations of seasons, times of sowing and levels of irrigation created large variations in growth conditions that affected the growth and production of the crops. Early sowing increased yield by transferring water use from vegetative to reproductive stages and increasing grain numbers in tillers. Cold temperatures in the early sowing times tended to produce smaller crops with smaller rooting systems, smaller root-to-shoot ratios, and larger average root diameters. Total root length and root length density increased with increasing pre-flowering mean air temperatures up to 20 °C. Linear relationships were observed between an EMI derived index of root activity and the empirically determined values of root length density (cm cm−3) at flowering. Conclusions Sowing sorghum, a summer crop, early in late winter or spring transferred water use from vegetative stages to flowering and post-flowering stages increasing crop water use later in the season. Root length and root length density were reduced by pre-flowering mean temperatures lower than 20 °C, indicating a need to increase cold tolerance for early sowing. The higher grain numbers in early sown crops were related to higher grain numbers in tillers. The EMI derived index of root activity has a potential in the development of high throughput root phenotyping applications.

show abstract

Root phenotypic plasticity: agronomic, breeding and modelling implications

Cited by 3 publications

References 56 publications

Does late water deficit induce root growth or senescence in wheat?

Does late water deficit induce root growth or senescence in wheat?

DataSheet_1.docx

Sowing summer grain crops early in late winter or spring: effects on root growth, water use, and yield

Contact Info

Product

Resources

About