scholarly journals Key root traits of Poaceae for adaptation to soil water gradients

2020 ◽  
Author(s):  
Takaki Yamauchi ◽  
Ole Pedersen ◽  
Mikio Nakazono ◽  
Nobuhiro Tsutsumi
Keyword(s):  
Soil Water ◽  
Root Traits ◽  
Water Gradients

scholarly journals Large root systems: are they useful in adapting wheat to dry environments?

2011 ◽  
Vol 38 (5) ◽  
pp. 347 ◽  
Author(s):  
Jairo A. Palta ◽  
Xing Chen ◽  
Stephen P. Milroy ◽  
Greg J. Rebetzke ◽  
M. Fernanda Dreccer ◽  
...  
Keyword(s):  
Root System ◽  
Soil Water ◽  
Field Experiments ◽  
Root Length Density ◽  
Root Traits ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
System Size ◽  
Large Root ◽  
Additional Water

There is little consensus on whether having a large root system is the best strategy in adapting wheat (Triticum aestivum L.) to water-limited environments. We explore the reasons for the lack of consensus and aim to answer the question of whether a large root system is useful in adapting wheat to dry environments. We used unpublished data from glasshouse and field experiments examining the relationship between root system size and their functional implication for water capture. Individual root traits for water uptake do not describe a root system as being large or small. However, the recent invigoration of the root system in wheat by indirect selection for increased leaf vigour has enlarged the root system through increases in root biomass and length and root length density. This large root system contributes to increasing the capture of water and nitrogen early in the season, and facilitates the capture of additional water for grain filling. The usefulness of a vigorous root system in increasing wheat yields under water-limited conditions maybe greater in environments where crops rely largely on seasonal rainfall, such as the Mediterranean-type environments. In environments where crops are reliant on stored soil water, a vigorous root system increases the risk of depleting soil water before completion of grain filling.

Wheats developed for high yield on stored soil moisture have deep vigorous root systems

2016 ◽  
Vol 43 (2) ◽  
pp. 173 ◽  
Author(s):  
Sarah M. Rich ◽  
Anton P. Wasson ◽  
Richard A. Richards ◽  
Trushna Katore ◽  
Renu Prashar ◽  
...  
Keyword(s):  
Root System ◽  
Soil Water ◽  
Production Systems ◽  
System Development ◽  
Root Traits ◽  
Grain Filling ◽  
Root Systems ◽  
High Yield ◽  
Eastern Australia ◽  
Mature Root

Many rainfed wheat production systems are reliant on stored soil water for some or all of their water inputs. Selection and breeding for root traits could result in a yield benefit; however, breeding for root traits has traditionally been avoided due to the difficulty of phenotyping mature root systems, limited understanding of root system development and function, and the strong influence of environmental conditions on the phenotype of the mature root system. This paper outlines an international field selection program for beneficial root traits at maturity using soil coring in India and Australia. In the rainfed areas of India, wheat is sown at the end of the monsoon into hot soils with a quickly receding soil water profile; in season water inputs are minimal. We hypothesised that wheat selected and bred for high yield under these conditions would have deep, vigorous root systems, allowing them to access and utilise the stored soil water at depth around anthesis and grain-filling when surface layers were dry. The Indian trials resulted in 49 lines being sent to Australia for phenotyping. These lines were ranked against 41 high yielding Australian lines. Variation was observed for deep root traits e.g. in eastern Australia in 2012, maximum depth ranged from 118.8 to 146.3 cm. There was significant variation for root traits between sites and years, however, several Indian genotypes were identified that consistently ranked highly across sites and years for deep rooting traits.

Impact of vegetation species on soil pore system and soil hydraulic properties in the high Andes

2020 ◽  
Author(s):  
Sebastián Páez-Bimos ◽  
Veerle Vanacker ◽  
Marcos Villacís ◽  
Oscar Morales ◽  
Marlon Calispa ◽  
...  
Keyword(s):  
Soil Water ◽  
Soil Structure ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Root Traits ◽  
High Elevation ◽  
Soil Hydraulic Properties ◽  
Pore System ◽  
Soil Hydraulic ◽  
Vegetation Species

<p>Soils play a key role in the provision of vital ecosystem services. Soil functions, that deliver these services, are governed by soil properties.  Soil structure is a fundamental property of soils since it controls water, geochemical and biological processes.  The soil pore system, one of the main components of soil structure, can be affected by different biological feedbacks. Vegetation can have an impact on soil pore system through changes in pore size distribution and porosity, causing differences in soil hydraulic properties as well as soil-water processes.</p><p>In high elevation tropical Andean ecosystems (páramos) little is still known about vegetation feedbacks on soil properties. At high elevation páramos (above 4100m), it is possible to find high diversity and co-dominance of plant species over short distances. In these landscapes, cushion plants and tussock grasses dominate alongside shrubs. These vegetation types, adapted to extreme local climatic conditions, are placed on young volcanic soils. We take advantage of this diverse setting, located within Antisana´s water conservation area in the north of Ecuador, by studying soil hydraulic properties and soil pore system in eight soil profiles. We hypothesize that the effect caused by Calamagrostis intermedia (tussock) and Azorella pedunculata (cushion) species on soil pore system and soil hydraulic properties at different horizons will be statistically different. In addition, we explore these effects in relation to other soil's physical properties and root traits.</p><p>Soil hydraulic properties were determined on the basis of field observed saturated hydraulic conductivity as well as based on water retention contents at saturation (porosity), field capacity and permanent wilting point measured in the laboratory by the multi-step outflow method and the porous membrane pressure cell. Furthermore, water retention curves were fitted to measured data by the bimodal van Genuchten model. Based on these fittings the pore size distribution was determined. Equivalent pore diameters were derived from the soil water tension head via the capillary rise equation. Statistical analysis to determine differences was carried out by means of the Mann-Whitney U test.        </p><p>The results show that measurable differences in soil hydraulic properties and soil pore system between vegetation species are present at the upper soil horizons, while they become negligible at greater depth. These differences are mainly related to bulk density and root traits. Based on this baseline study, further research could elucidate the effects of vegetation species on soil-water processes at high elevation páramo landscapes and will contribute to enhancing water resources management.</p>

scholarly journals Fiber-parenchyma trade-off underlies changes in tropical forest structure and xylem architecture across a soil water gradient

2022 ◽  
Author(s):  
Jehova Lourenco ◽  
Paulo Roberto de Lima Bittencourt ◽  
Brian Joseph Enquist ◽  
Georg von Arx ◽  
Kiyomi Morino ◽  
...  
Keyword(s):  
Environmental Change ◽  
Tropical Forest ◽  
Soil Water ◽  
Resource Use ◽  
Forest Structure ◽  
Maximum Height ◽  
Trade Off ◽  
Hydraulic Safety ◽  
Water Gradient ◽  
Water Gradients

Wood anatomical traits can underpin tropical forest structural and functional changes across soil water gradients and therefore could improve our mechanistic understanding of how plants adapt to environmental change. We assessed how the variation in the forest maximum height (Hmax), stem diameter, and wood density (WD) is associated with variation in xylem traits (area of fibers and parenchyma, conductive area [CondA, sum of all vessels lumens], vessel lumen area [VLA], vessel density [VD], and vessel wall reinforcement [VWR]) across 42 plots of a Brazilian Atlantic Forest habitat that span strong soil water gradients. We found that in wetter communities, greater height and lower WD were associated with greater parenchyma area (capacitance), and lower fibers, VD, VWR. Contrastingly, in drier communities, lower height was associated with higher fiber area (xylem reinforcement), WD, VD, and VWR, while parenchyma area and vessels are reduced. Tree communities vary from conservative resource-use and structurally dependent hydraulic safety (Fibers) to acquisitive resource-use and capacitance dependent hydraulic safety (parenchyma). Such a fiber-parenchyma trade-off (FPT) underlies the variation in tree height across a soil water gradient. Wood anatomy is fundamental to understanding and predicting the impacts of environmental change on forest structure.

scholarly journals Pulse Root Ideotype for Water Stress in Temperate Cropping System

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 692
Author(s):  
Shiwangni Rao ◽  
Roger Armstrong ◽  
Viridiana Silva-Perez ◽  
Abeya T. Tefera ◽  
Garry M. Rosewarne
Keyword(s):  
Water Stress ◽  
Root System ◽  
Soil Water ◽  
System Architecture ◽  
Cropping Systems ◽  
Root Traits ◽  
Root System Architecture ◽  
Pulse Crops ◽  
Available Water ◽  
Plant Available Water

Pulses are a key component of crop production systems in Southern Australia due to their rotational benefits and potential profit margins. However, cultivation in temperate cropping systems such as that of Southern Australia is limited by low soil water availability and subsoil constraints. This limitation of soil water is compounded by the irregular rainfall, resulting in the absence of plant available water at depth. An increase in the productivity of key pulses and expansion into environments and soil types traditionally considered marginal for their growth will require improved use of the limited soil water and adaptation to sub soil constrains. Roots serve as the interface between soil constraints and the whole plant. Changes in root system architecture (RSA) can be utilised as an adaptive strategy in achieving yield potential under limited rainfall, heterogenous distribution of resources and other soil-based constraints. The existing literature has identified a “‘Steep, Deep and Cheap” root ideotype as a preferred RSA. However, this idiotype is not efficient in a temperate system where plant available water is limited at depth. In addition, this root ideotype and other root architectural studies have focused on cereal crops, which have different structures and growth patterns to pulses due to their monocotyledonous nature and determinant growth habit. The paucity of pulse-specific root architectural studies warrants further investigations into pulse RSA, which should be combined with an examination of the existing variability of known genetic traits so as to develop strategies to alleviate production constraints through either tolerance or avoidance mechanisms. This review proposes a new model of root system architecture of “Wide, Shallow and Fine” roots based on pulse roots in temperate cropping systems. The proposed ideotype has, in addition to other root traits, a root density concentrated in the upper soil layers to capture in-season rainfall before it is lost due to evaporation. The review highlights the potential to achieve this in key pulse crops including chickpea, lentil, faba bean, field pea and lupin. Where possible, comparisons to determinate crops such as cereals have also been made. The review identifies the key root traits that have shown a degree of adaptation via tolerance or avoidance to water stress and documents the current known variability that exists in and amongst pulse crops setting priorities for future research.

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