scholarly journals Root growth of soybean cultivars under different water availability conditions

2017 ◽  
Vol 38 (2) ◽  
pp. 715 ◽  
Author(s):  
Julio Cezar Franchini ◽  
Alvadi Antonio Balbinot Junior ◽  
Henrique Debiasi ◽  
Alexandre Lima Nepomuceno

Vigorous growth of soybean root system is a desired trait in breeding programs. However, few studies have evaluated this feature under field conditions. The aim of this research was to evaluate root growth of eight soybean cultivars under different water availability conditions. The experiment was carried out in Londrina, Paraná state, Brazil, during two growing seasons - with and without water deficit during the vegetative period. Soybean roots were sampled at flowering and assessed for dry matter yield, area and length at 0-0.25; 0.25-0.50; 0.50-0.75 and 0.75-1.00 m depth ranges. On average, root length and area of the cultivars Embrapa 48 and BRS 284 under water deficit were 66% and 40% larger than the others at 0.25-0.50 and 0.50-0.75 m layers, respectively. Under suitable water supply, BRS 282 showed the highest root length and area. Apart from the cultivars Embrapa 48, BRS 284, and BRS 255RR, soybean root growth was mostly lower under water deficit throughout the vegetative stage, which might been due to a higher soil resistance to root penetration, resulting from low soil water content. Drought increased the proportion of soybean roots at subsoil layers, mainly for Embrapa 48 and BRS 284. The cultivars Embrapa 48 and BRS 284 are promising to be used in breeding programs targeting superior root growth in subsoil layers.

1990 ◽  
Vol 17 (2) ◽  
pp. 189 ◽  
Author(s):  
JW White ◽  
JA Castillo ◽  
J Ehleringer

Recent theoretical and empirical studies have indicated that isotopic discrimination against 13C (Δ) during photosynthesis in C3 plants reflects variation in intercellular CO2 concentration (ci). Under water deficit, cultivar differences in Δ may indicate differences in leaf gas exchange characteristics. Cultivar differences in Δ may also result indirectly from genetic variation in root characteristics affecting the level of water stress experienced by the canopy. Differences in root growth affecting the degree of dehydration postponement could prolong gas exchange activity and the maintenance of relatively high ci and Δ. To evaluate relations between root growth, productivity and Δ in common bean (Phaseolus vulgaris L.), Δ and crop growth parameters, including biomass production, grain yield and root length density, were determined for ten bean genotypes grown under rainfed conditions at two sites in Colombia which differed primarily in soil fertility and effective rooting depth. The 10 genotypes were also grown under irrigation at the more fertile site. Under rainfed conditions, root length density was positively correlated with Δ in the fertile Mollisol at Palmira, and was also positively correlated with Δ in the infertile Oxisol at Quilichao if one possibly abberent genotype was excluded. At Palmira, reduced crop growth and seed yield were associated with low Δ values. At Quilichao, intermediate Δ values were associated with the greatest growth and yield. Under irrigation at Palmira there was no association between growth or yield and Δ.


2003 ◽  
Vol 46 (2) ◽  
pp. 193-198 ◽  
Author(s):  
Patrícia Minatovicz F. Doblinski ◽  
Maria de Lourdes L. Ferrarese ◽  
Domitila A. Huber ◽  
Carlos Alberto Scapim ◽  
Alessandro de Lucca e Braccini ◽  
...  

The scope of the present study was to investigate how the p-coumaric (p-CA) and p-hydroxybenzoic (p-HD) acids affect the peroxidase (POD, EC 1.11.1.7) activity, the lipid peroxidation (LP) and the root growth of soybean (Glycine max (L.) Merr.). Three-day-old seedlings were cultivated in nutrient solution containing p-CA or p-HD (0.1 to 1 mM) for 48 h. After uptake, both compounds (at 0.5 and 1 mM) decreased root length (RL), fresh weight (FW) and dry weight (DW) while increased soluble POD activity, cell wall (CW)-bound POD activity (with 1 mM p-CA and 0.5 mM p-HD) and LP.


2020 ◽  
Vol 1 (1) ◽  
pp. 21
Author(s):  
Danner Sagala ◽  
Eka Suzanna ◽  
Prihanani Prihanani

Aluminum is prevalent in soils of tidal swamps. Soybean is known to be very sensitive to aluminum stress and so when tidal swamps are converted to soybean cropland, considerable effort and expense are required to overcome Al toxicity in soybean roots. It is therefore necessary to determine at what time in early development soybeans can best endure aluminum stress and identify aluminum-tolerant cultivars. This study was conducted by testing the impact of aluminum exposure on three soybean cultivars (Tanggamus, Karasumame, and M652) (relative to no-exposure controls) at four time periods at 10, 20, and 30 days after planting. No significant effect of aluminum on root growth in the first five days after exposure was observed, but the toxic effects became evident after soybeans had been exposed to aluminum for 10 days. Soybean seedlings that experienced aluminum stress earliest (at 10 days after planting) were more negatively impacted by Al exposure than seedlings exposed later (e.g., 30 days after planting). Root growths of the three cultivars we tested in this study were all detrimentally impacted by aluminum exposure. However, the M652 cultivar was the most sensitive to aluminum exposure. We conclude that the critical threshold period for soybean root growth to succumb to aluminum stress is within the first 30 days after planting, whereas the tolerance to aluminum stress occurs only during the first 10 days of exposure.


2016 ◽  
Vol 113 (31) ◽  
pp. 8861-8866 ◽  
Author(s):  
Jose Sebastian ◽  
Muh-Ching Yee ◽  
Willian Goudinho Viana ◽  
Rubén Rellán-Álvarez ◽  
Max Feldman ◽  
...  

Many important crops are members of the Poaceae family, which develop root systems characterized by a high degree of root initiation from the belowground basal nodes of the shoot, termed the crown. Although this postembryonic shoot-borne root system represents the major conduit for water uptake, little is known about the effect of water availability on its development. Here we demonstrate that in the model C4 grass Setaria viridis, the crown locally senses water availability and suppresses postemergence crown root growth under a water deficit. This response was observed in field and growth room environments and in all grass species tested. Luminescence-based imaging of root systems grown in soil-like media revealed a shift in root growth from crown-derived to primary root-derived branches, suggesting that primary root-dominated architecture can be induced in S. viridis under certain stress conditions. Crown roots of Zea mays and Setaria italica, domesticated relatives of teosinte and S. viridis, respectively, show reduced sensitivity to water deficit, suggesting that this response might have been influenced by human selection. Enhanced water status of maize mutants lacking crown roots suggests that under a water deficit, stronger suppression of crown roots actually may benefit crop productivity.


1986 ◽  
Vol 37 (4) ◽  
pp. 375 ◽  
Author(s):  
AK Alva ◽  
CJ Asher ◽  
DG Edwards

Effects of varying calcium (Ca) concentration at constant or varying solution ionic strength on root elongation of soybean (Glycine max (L.) Merr.) and subterranean clover (Trifolium subterraneum L.) were determined in aluminium (Al) free nutrient solution or solutions containing monomeric Al activities (+aAl mono) of 8-10 8M for subterranean clover and 20-22 8M for soybean. In Al-free solutions, the root length for subterranean clover was not significantly influenced by Ca or ionic strength. However, soybean root length was greater at 500 8M Ca than at higher Ca concentrations. Raising the ionic strength at 500 and 5000 8M Ca significantly decreased root length. In the presence of Al, maximum root length of both species occurred at 15 000 8M Ca. Soybean root length at 500 and 5000 8M Ca was 35% and 87% respectively of that at 15000 8M Ca. The corresponding values for subterranean clover were 53% and 81%. The positive effect of Ca concentration on root length, despite a nearly constant +aAL mono, confirms the existence of a protective action of Ca against Al toxicity. Raising the solution ionic strength at 500 8M Ca in the presence of Al improved the root growth of soybean by 86% and that of subterranean clover by 45%. At 5000 8M Ca, a small beneficial effect of increased ionic strength (14%) was found only in subterranean clover. Increasing Ca concentration in solution decreased water extractable and 0-1 M HNO3 extractable Al in roots of both plant species. Transfer of soybean seedlings to Al-free nutrient solutions containing 500, 1500 or 5000 pM Ca after 24, 48 or 96 h in a solution containing +aAL mono of 22 8M resulted in a substantial recovery in primary root growth. Relative root lengths were in each case significantly higher at 5000 8M Ca than at 1500 or 500 pM Ca. Roots transferred to 500 8M Ca after exposure to Al for 6 or 18 h underwent a period of accelerated elongation after a lag period of 30-40 h. By 138 h there were no significant differences in root length between the unstressed control plants and those subjected to 6 or 18 h Al-stress.


Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2177
Author(s):  
Felix Frimpong ◽  
Michael Anokye ◽  
Carel W. Windt ◽  
Ali A. Naz ◽  
Michael Frei ◽  
...  

A vigorous root system in barley promotes water uptake from the soil under water-limited conditions. We investigated three spring barley genotypes with varying water stress responses using rhizoboxes at the seedling stage. The genotypes comprised two elite German cultivars, Barke and Scarlett, and a near-isogenic line, NIL 143. The isogenic line harbors the wild allele pyrroline-5-carboxylate synthase1-P5cs1. Root growth in rhizoboxes under reduced water availability conditions caused a significant reduction in total root length, rooting depth, root maximum width, and root length density. On average, root growth was reduced by more than 20% due to water stress. Differences in organ proline concentrations were observed for all genotypes, with shoots grown under water stress exhibiting at least a 30% higher concentration than the roots. Drought induced higher leaf and root proline concentrations in NIL 143 compared with any of the other genotypes. Under reduced water availability conditions, NIL 143 showed less severe symptoms of drought, higher lateral root length, rooting depth, maximum root width, root length density, and convex hull area compared with Barke and Scarlett. Within the same comparison, under water stress, NIL 143 had a higher proportion of lateral roots (+30%), which were also placed at deeper substrate horizons. NIL 143 had a less negative plant water potential and higher relative leaf water content and stomatal conductance compared with the other genotypes under water stress. Under these conditions, this genotype also maintained an enhanced net photosynthetic rate and exhibited considerable fine root growth (diameter class 0.05–0.35 mm). These results show that water stress induces increased shoot and root proline accumulation in the NIL 143 barley genotype at the seedling stage and that this effect is associated with increased lateral root growth.


2021 ◽  
Vol 22 (10) ◽  
pp. 5314
Author(s):  
Marlon-Schylor L. le Roux ◽  
Nicolas Francois V. Burger ◽  
Maré Vlok ◽  
Karl J. Kunert ◽  
Christopher A. Cullis ◽  
...  

Drought response in wheat is considered a highly complex process, since it is a multigenic trait; nevertheless, breeding programs are continuously searching for new wheat varieties with characteristics for drought tolerance. In a previous study, we demonstrated the effectiveness of a mutant known as RYNO3936 that could survive 14 days without water. In this study, we reveal another mutant known as BIG8-1 that can endure severe water deficit stress (21 days without water) with superior drought response characteristics. Phenotypically, the mutant plants had broader leaves, including a densely packed fibrous root architecture that was not visible in the WT parent plants. During mild (day 7) drought stress, the mutant could maintain its relative water content, chlorophyll content, maximum quantum yield of PSII (Fv/Fm) and stomatal conductance, with no phenotypic symptoms such as wilting or senescence despite a decrease in soil moisture content. It was only during moderate (day 14) and severe (day 21) water deficit stress that a decline in those variables was evident. Furthermore, the mutant plants also displayed a unique preservation of metabolic activity, which was confirmed by assessing the accumulation of free amino acids and increase of antioxidative enzymes (peroxidases and glutathione S-transferase). Proteome reshuffling was also observed, allowing slow degradation of essential proteins such as RuBisCO during water deficit stress. The LC-MS/MS data revealed a high abundance of proteins involved in energy and photosynthesis under well-watered conditions, particularly Serpin-Z2A and Z2B, SGT1 and Calnexin-like protein. However, after 21 days of water stress, the mutants expressed ABC transporter permeases and xylanase inhibitor protein, which are involved in the transport of amino acids and protecting cells, respectively. This study characterizes a new mutant BIG8-1 with drought-tolerant characteristics suited for breeding programs.


2021 ◽  
Author(s):  
Simone F da Silva ◽  
Marcela T Miranda ◽  
Vladimir E Costa ◽  
Eduardo C Machado ◽  
Rafael V Ribeiro

Abstract Carbon allocation between source and sink organs determines plant growth and is influenced by environmental conditions. Under water deficit, plant growth is inhibited before photosynthesis and shoot growth tends to be more sensitive than root growth. However, the modulation of source-sink relationship by rootstocks remain unsolved in citrus trees under water deficit. Citrus plants grafted on Rangpur lime are drought tolerant, which may be related to a fine coordination of the source-sink relationship for maintaining root growth. Here, we followed 13C allocation and evaluated physiological responses and growth of Valencia orange trees grafted on three citrus rootstocks (Rangpur lime, Swingle citrumelo and Sunki mandarin) under water deficit. As compared to plants on Swingle and Sunki rootstocks, ones grafted on Rangpur lime showed higher stomatal sensitivity to the initial variation of water availability and less accumulation of non-structural carbohydrates in roots under water deficit. High 13C allocation found in Rangpur lime roots indicates this rootstock has high sink demand associated with high root growth under water deficit. Our data suggest that Rangpur lime rootstock used photoassimilates as sources of energy and carbon skeletons for growing under drought, which is likely related to increases in root respiration. Taken together, our data revealed that carbon supply by leaves and delivery to roots are critical for maintaining root growth and improving drought tolerance, with citrus rootstocks showing differential sink strength under water deficit.


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