Modelling the effect of varying soil water on root growth dynamics of annual crops

1996 ◽  
Vol 185 (1) ◽  
pp. 125-135 ◽  
Author(s):  
S. G. K. Adiku ◽  
R. D. Braddock ◽  
C. W. Rose
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Growth Dynamics ◽  
Annual Crops

scholarly journals Lateral Root Priming Synergystically Arises from Root Growth and Auxin Transport Dynamics

2018 ◽  
Author(s):  
Thea van den Berg ◽  
Kirsten H. ten Tusscher
Keyword(s):  
Cell Cycle ◽  
Root Growth ◽  
Lateral Root ◽  
Root Formation ◽  
Growth Dynamics ◽  
Root Tip ◽  
Cycle Duration ◽  
Elongation Zone ◽  
Lateral Root Formation ◽  
Cell Cycle Duration

AbstractThe root system is a major determinant of plant fitness. Its capacity to supply the plant with sufficient water and nutrients strongly depends on root system architecture, which arises from the repeated branching off of lateral roots. A critical first step in lateral root formation is priming, which prepatterns sites competent of forming a lateral root. Priming is characterized by temporal oscillations in auxin, auxin signalling and gene expression in the root meristem, which through growth become transformed into a spatially repetitive pattern of competent sites. Previous studies have demonstrated the importance of auxin synthesis, transport and perception for the amplitude of these oscillations and their chances of producing an actual competent site. Additionally, repeated lateral root cap apoptosis was demonstrated to be strongly correlated with repetitive lateral root priming. Intriguingly, no single mutation has been identified that fully abolishes lateral root formation, and thusfar the mechanism underlying oscillations has remained unknown. In this study, we investigated the impact of auxin reflux loop properties combined with root growth dynamics on priming, using a computational approach. To this end we developed a novel multi-scale root model incorporating a realistic root tip architecture and reflux loop properties as well as root growth dynamics. Excitingly, in this model, repetitive auxin elevations automatically emerge. First, we show that root tip architecture and reflux loop properties result in an auxin loading zone at the start of the elongation zone, with preferential auxin loading in narrow vasculature cells. Second, we demonstrate how meristematic root growth dynamics causes regular alternations in the sizes of cells arriving at the elongation zone, which subsequently become amplified during cell expansion. These cell size differences translate into differences in cellular auxin loading potential. Combined, these properties result in temporal and spatial fluctuations in auxin levels in vasculature and pericycle cells. Our model predicts that temporal priming frequency predominantly depends on cell cycle duration, while cell cycle duration together with meristem size control lateral root spacing.

Genetic variability for root morph-architecture traits and root growth dynamics as related to phosphorus efficiency in soybean

2010 ◽  
Vol 37 (4) ◽  
pp. 304 ◽  
Author(s):  
Junhua Ao ◽  
Jiabing Fu ◽  
Jiang Tian ◽  
Xiaolong Yan ◽  
Hong Liao
Keyword(s):  
Genetic Variability ◽  
Root Growth ◽  
Recombinant Inbred Lines ◽  
Growth Dynamics ◽  
Root Traits ◽  
Phosphorus Efficiency ◽  
P Efficiency ◽  
Glycine Max L ◽  
Positive Correlations

Root morphology and architecture are believed to be important for plant phosphorus (P) efficiency, but their genetic information is relatively scarce. In the present study, a field and a specially designed minirhizotron experiments were conducted using two soybean (Glycine max L. Merr.) genotypes and their 88 recombinant inbred lines (RILs) to elucidate the genetic variability for root morph-architecture traits and root growth dynamics as related to P efficiency in soybean. The results indicated that the root morph-architecture traits were continually segregated in the RILs with a normal distribution, indicating which are possibly controlled by quantitative trait loci. Significantly positive correlations were found between root and P traits, suggesting feasibility of screening P efficient genotype through simple selection of root traits in field. Most root morph-architecture traits were closely correlated, showing a coordinating contribution to P efficiency. Furthermore, root morphological traits always had higher heritability than architecture traits, thus, could serve as more reliable index in field selection. The dynamic parameters of root growth from the minirhizotron experiment showed that the P efficient genotype established longer and larger root system with preferring distribution in surface layer and also kept more active roots, therefore, had a better growth performance in field, than the P-inefficient genotype. Taken together, this is the first report on in situ root growth dynamics and its relation to P efficiency using minirhizotron systems in crops. Our findings help to better understand the relationships between P efficiency and root traits and, thus, facilitate development of P efficient genotypes in crops.

Lime-slotting technique to ameliorate subsoil acidity in a clay soil II. Effects on medic root-growth, water extraction and yield

Soil Research ◽  
1995 ◽  
Vol 33 (3) ◽  
pp. 443 ◽  
Author(s):  
NS Jayawardane ◽  
HD Barrs ◽  
WA Muirhead ◽  
J Blackwell ◽  
E Murray ◽  
...  
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Surface Area ◽  
Dry Matter ◽  
Acid Soil ◽  
Water Extraction ◽  
Undisturbed Soil ◽  
Subsoil Acidity ◽  
Soil Water Extraction ◽  
Limed Soil

Subsoil acidity causes low crop production, which is often associated with shallow root development and restricted soil water extraction. In part I of this series, lime-slotting of an acid soil was shown to improve the soil physical and chemical characteristics for root growth. In a lysimeter study on an acid soil, the effects of several soil ameliorative treatments on root growth, water extraction and yields of a medic crop were evaluated. Large lysimeter cores of 0.75 m diameter and 1.35 m deep were used. The soil treatments included a non-ameliorated acid soil, lime-slotting with a 0.15 m wide and 0.8 m deep slot containing 20 t ha-1 of lime, lime-slotting combined with surface phospho-gypsum application at 10 t ha-1, and complete amelioration of the entire soil volume by mixing lime at 133 t ha-1 and repacking to a low bulk density of 1.1 t m-3. In the non-ameliorated acid soil, medic roots were confined to the surface (0.1 m) layer, resulting in limited water extraction of 32 mm during a prolonged drying cycle, and a low dry matter yield of 70 g m-2. In the lime slotted soil, roots grew within the slot to its full depth, although penetration into the undisturbed soil was restricted to the soil immediately adjacent to the slot. Consequently, the root length per unit surface area (La) at depths below 0.1 m depth was increased to 9.9 km m-2. During a drying cycle, water extraction increased to 58 mm. The increased water extraction came from both the slotted soil and the undisturbed soil between slots. This led to an increase in dry matter yields to 270 g m2. In lime-slotted soils with surface gypsum applications, the root growth and crop water extraction patterns were similar to the lime-slotted soil. Repacking limed soil resulted in similar root lengths (L(a) 10.0 km m-2) as lime-slotted soil. However, owing to more uniform distribution of roots in the repacked soil, water extraction was increased to 100 mm and yields increased to 590 g m-2. Yields of non-ameliorated soil were only 12% of the repacked, limed soil. However, lime-slotting which involves loosening only 25% of the soil surface area and addition of only one-sixth of the amount of lime required for complete soil amelioration, led to marked increases in yield (46% of the yield of repacked soil). Future field studies are required to evaluate the optimum limed-slot configurations required for different soils, crops and climatic regimes.

EFFECT OF SOIL WATER AND TEMPERATURE ON CORN (Zea mays L.) ROOT GROWTH DURING EMERGENCE

1986 ◽  
Vol 66 (1) ◽  
pp. 51-58 ◽  
Author(s):  
H. W. CUTFORTH ◽  
C. F. SHAYKEWICH ◽  
C. M. CHO
Keyword(s):  
Root Growth ◽  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Zea Mays L ◽  
Rate Sensitivity ◽  
Corn Hybrids ◽  
Soil Water Stress ◽  
Soil Temperatures ◽  
Water Contents

Root growth between germination and emergence for the corn hybrids Pioneer 3995, Northrup King 403 and Pride 1108 was studied. Soil temperatures of 15, 19, 25 and 30.5 °C and a range of soil water contents were used. Decreases in soil temperature and water content both decreased root growth rate. Sensitivity to water content decreased with decreasing soil temperature. All three hybrids responded to soil temperature in the same way. By contrast, Pioneer 3995 was less sensitive to soil water stress than was Northrup King 403, while Pride 1108 was the most sensitive. Key words: Soil water, soil temperature, root growth (early), corn

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