scholarly journals Reallocation to lateral and early-emerging axial roots allows maize (Zea mays L.) with reduced nodal root number to more efficiently forage for nitrate

2019 ◽  
Author(s):  
Haichao Guo ◽  
Larry M. York
Keyword(s):  
Zea Mays ◽  
Root Length ◽  
Foraging Efficiency ◽  
Shoot Biomass ◽  
Total Biomass ◽  
Root Number ◽  
Nodal Roots ◽  
Solid Media ◽  
Nodal Root ◽  
Shoot Mass

ABSTRACTPrevious simulations indicated reduced nodal root number (NRN) was promising for maize (Zea mays L.) breeding, and were partially confirmed using variation in NRN among inbreds. However, the exact mechanism was unknown, therefore manipulative experiments were conducted in hydroponics and tall solid-media mesocosms with treatments involving no nodal root excision (0% NRE) or excising either 33% or 67% of the nodal roots (NR) as they emerged under high or low levels of nitrogen (N). Reduced NRN was hypothesized to increase elongation of all remaining root classes, increase N acquisition under low N, and increase shoot mass. In both experiments, plants with 67% NRE had 12% and 19% less root fraction of total biomass, 61% and 91% greater lateral-to-axial root length ratio regardless of N levels; and 61% and 182% greater biomass of embryonic roots under low N, compared to 0% NRE for hydroponics and mesocosms studies, respectively. In hydroponics, regardless of NRE level, specific root respiration under high N was 2.6 times of low N, and was greatest at depth. Under low N in mesocosms, plants with 67% NRE had 52% greater shoot biomass, 450% greater root length at depth, and 232% greater deep-injected 15N content in the shoot relative to 0% NRE, however biomass in hydroponics did not differ based on NRE. These results reveal the mechanism by which plants with fewer nodal roots increase N capture and shoot mass by reallocation of biomass to lateral, embryonic, and first whorl nodal roots that increases foraging efficiency in solid media.SummaryReallocating root biomass from nodal roots to lateral and early-emerging axial roots allows grasses to capture more nitrogen under limiting conditions, including by increasing foraging at depth.

scholarly journals Nodal root diameter and node number in maize (Zea mays L.) interact to influence plant growth under nitrogen stress

2020 ◽  
Author(s):  
Hannah M. Schneider ◽  
Jennifer T. Yang ◽  
Kathleen M. Brown ◽  
Jonathan P. Lynch
Keyword(s):  
Shoot Growth ◽  
Cross Sectional Area ◽  
Nitrogen Stress ◽  
Sectional Area ◽  
Root Number ◽  
Cross Sectional ◽  
Nitrogen Acquisition ◽  
Nodal Roots ◽  
Nodal Root ◽  
Low Nitrogen

AbstractUnder nitrogen limitation, plants increase resource allocation to root growth relative to shoot growth. The utility of various root architectural and anatomical phenotypes for nitrogen acquisition are not well understood. Nodal root number and root cross-sectional area were evaluated in maize in field and greenhouse environments. Nodal root number and root cross-sectional area were inversely correlated under both high and low nitrogen conditions. Attenuated emergence of root nodes, as opposed to differences in the number of axial roots per node, was associated with substantially reduced root number. Greater root cross-sectional area was associated with a greater stele area and number of cortical cell files. Genotypes that produced few, thick nodal roots rather than many, thin nodal roots had deeper rooting and better shoot growth in low nitrogen environments. Fewer nodal roots offset the respiratory and nitrogen costs of thicker diameter roots, since total nodal root respiration and nitrogen content was similar for genotypes with many, thin and few, thick nodal roots. We propose that few, thick nodal roots may enable greater capture of deep soil nitrogen and improve plant performance under nitrogen stress. The interaction between an architectural and anatomical trait may be an important strategy for nitrogen acquisition. Understanding trait interactions among different root nodes has important implications in for improving crop nutrient uptake and stress tolerance.

scholarly journals Antagonism of chloride and nitrate inhibits nitrate reductase activity in chloride-stressed maize

2021 ◽  
Author(s):  
Xudong Zhang ◽  
Bastian L. Franzisky ◽  
Lars Eigner ◽  
Christoph‐Martin Geilfus ◽  
Christian Zörb
Keyword(s):  
Zea Mays ◽  
Polyethylene Glycol ◽  
Nitrate Reductase ◽  
Osmotic Stress ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Shoot Biomass ◽  
Lower Intensity ◽  
Maize Variety ◽  
Osmotic Balance

AbstractChloride (Cl−) is required for photosynthesis and regulates osmotic balance. However, excess Cl− application negatively interacts with nitrate ($${\mathrm{NO}}_{3}^{-}$$ NO 3 - ) uptake, although its effect on $${\mathrm{NO}}_{3}^{-}$$ NO 3 - metabolism remains unclear. The aim was to test whether Cl− stress disturbs nitrate reductase activity (NRA). A maize variety (Zea mays L. cv. LG 30215) was hydroponically cultured in a greenhouse under the following conditions: control (2 mM CaCl2), moderate Cl− (10 mM CaCl2), high Cl− (60 mM CaCl2). To substantiate the effect of Cl− stress further, an osmotic stress with lower intensity was induced by 60 g polyethylene glycol (PEG) 6000 L−1 + 2 mM CaCl2), which was 57% of the osmotic pressure being produced by 60 mM CaCl2. Results show that high Cl− and PEG-induced osmotic stress significantly reduced shoot biomass, stomatal conductance and transpiration rate, but NRA was only decreased by high Cl− stress. The interference of NRA in chloride-stressed maize is supposed to be primarily caused by the antagonistic uptake of Cl− and $${\mathrm{NO}}_{3}^{-}$$ NO 3 - .

scholarly journals The Influence of Various Varieties and Various Liquid Organic Fertilizer to Papaya Plant Seed Growth (Carica papaya L.)

AGRIFOR ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 153
Author(s):  
Primadiyanti Arsela
Keyword(s):  
Root Length ◽  
Carica Papaya ◽  
Block Design ◽  
Organic Fertilizer ◽  
Root Number ◽  
Plant Seed ◽  
Randomized Block Design ◽  
Seed Growth ◽  
Two Factors ◽  
All Treatment

The main goal of the study was to determine the effect of various  Papaya varieties and liquid organic fertilizer on the growth of Papaya seedlings(Carica papaya L.). The research used Randomized Block Design (RAK) with two factors factorial experimental. The first factor is Variety (V) consists of 3 Papaya varieties: v1= bangkok , v2= red lady , v3= sunrise. The second factor is Fertilizer (C) consists of 3 brands: c1= Em4 10 ml, c2= Green Tonic 10ml, c3= Nasa 10ml. This study has 3 treatment levels consisting of 9 combinations and  repeated 3 times. The results of the study are treatment of various varieties (V) had significant effect on stem diameter and root number. The effect of various liquid organic fertilizer (C) had significant effect on the root length parameters. The interaction all treatment had a very significant effect on the root length and the root number parameter. 

scholarly journals Direct Biotic Plant–soil Feedback Promotes Dodonaea Viscosa Growth in a Dry-hot Valley, China

2021 ◽  
Author(s):  
Xuemei Wang ◽  
Bangguo Yan ◽  
Liangtao Shi ◽  
Gangcai Liu
Keyword(s):  
Nutrient Cycling ◽  
Soil Biota ◽  
Shoot Biomass ◽  
Total Biomass ◽  
Conditioning Phase ◽  
Dodonaea Viscosa ◽  
Soil Sterilization ◽  
Plant Soil ◽  
Soil Feedback ◽  
Feedback Phase

Abstract Biotic plant-soil feedback has been widely studied, and may be particularly important in resource-poor areas. However, the roles of soil nutrient cycling in affecting plant growth in this process still remained unclear. The aim of this study was to explore the roles of soil biota in regulating nutrient cycling by conducting a two-phase feedback experiment in a dry-hot valley, with a conditioning phase during which there were Dodonaea viscosa or no D. viscosa growing in the soil, and a feedback phase in which the effect of the conditioned soil biota on D. viscosa performance was measured. The growth of D. viscosa significantly reduced soil N after the conditioning phase. However, D. viscosa showed a positive plant-soil feedback. In the feedback phase, the D. viscosa conditioned soil promoted the stem diameter, leaf area, and leaf dry mass content of D. viscosa. Total biomass was also significantly higher in D. viscosa conditioned soil than that in not conditioned soil. In contrast, soil sterilization had a negative effect on the growth of D. viscosa, with a significant reduction in plant biomass, especially in D. viscosa conditioned soil, and soil sterilization significantly increased the root: shoot biomass ratio and litter mass. Furthermore, we showed that although the biota-driven changes in enzyme activities correlated with the leaf N and P amount especially P amount, the enzyme activity was not the main reason to promote D. viscosa growth in the conditioned soil.

scholarly journals Wheat shovelomics I: A field phenotyping approach for characterising the structure and function of root systems in tillering species

2018 ◽  
Author(s):  
Larry M. York ◽  
Shaunagh Slack ◽  
Malcolm J Bennett ◽  
M John Foulkes
Keyword(s):  
Genetic Control ◽  
Principal Component ◽  
Root Systems ◽  
Wheat Root ◽  
Root Number ◽  
Main Shoot ◽  
Growth Angle ◽  
Nodal Root ◽  
Field Phenotyping ◽  
And Function

AbstractWheat represents a major crop, yet the current rate of yield improvement is insufficient to meet its projected global food demand. Breeding root systems more efficient for water and nitrogen capture represents a promising avenue for accelerating yield gains. Root crown phenotyping, or shovelomics, relies on excavation of the upper portions of root systems in the field and measuring root properties such as numbers, angles, densities and lengths. We report a new shovelomics method that images the whole wheat root crown, then partitions it into the main shoot and tillers for more intensive phenotyping. Root crowns were phenotyped using the new method from the Rialto × Savannah population consisting of both parents and 94 doubled-haploid lines. For the whole root crown, the main shoot, and tillers, root phenes including nodal root number, growth angle, length, and diameter were measured. Substantial variation and heritability were observed for all phenes. Principal component analysis revealed latent constructs that imply pleiotropic genetic control of several related root phenes. Correlational analysis revealed that nodal root number and growth angle correlate among the whole crown, main shoot, and tillers, indicating shared genetic control among those organs. We conclude that this phenomics approach will be useful for breeding ideotype root systems in tillering species.

scholarly journals Early root development of Eucalyptus pellita F. Muell. seedlings from seed and stem cutting at nursery stage

2020 ◽  
Author(s):  
Affendy Hassan ◽  
Parveena Balachandran ◽  
Khairiyyah Razanah Khamis
Keyword(s):  
Root Development ◽  
Root Length ◽  
Root Biomass ◽  
Nitrogen Concentration ◽  
Stem Cutting ◽  
Shoot Biomass ◽  
Forest Plantation ◽  
Plant Materials ◽  
Eucalyptus Pellita ◽  
Root Intensity

Abstract BackgroundEucalyptus is among the important fast-growing species, and is typically managed on short rotation to sustain the production of timber, pulpwood, charcoal, and fire-wood. Macro-propagation using cutting for larger multiplying seedlings is cheaper and efficient instead of clonal seeds for uniform plant material seedling production. However, information on root growth of Eucalyptus pellita at early development from seed and stem cutting of E. pellita seedlings is still lacking. This is probably due to the difficulty in investigation belowground, and also due to methodological problems. With such information, it is useful for forest plantation company management in enhancing the understanding on strategies to optimize yield production with the appropriate agronomic or silvicultural approach in the field planting. Therefore, the objectives of this study were; to compare the root development of two different propagation seedlings of E. pellita; and to study the effect of various nitrogen concentration levels on two types of propagation of E. pellita seedlings. ResultsThe study was conducted using E. pellita seedlings from two types of propagation, namely, seed and stem cuttings, along with three different nitrogen concentrations (0, 50, and 200 kg N ha-1). Shoot biomass, root intensity (RI), total root intensity (TRI), root biomass, root length density (RLD), and specific root length (SRL) were recorded. Dried shoot biomass, RLD and SRL of E. pellita seedlings using stem cutting were significantly higher (P<0.05) compared to seed. Whereas, there were no significant differences (P>0.05) for root biomass, TRI and RI between the propagation types of E. pellita seedlings. Conclusions:E. pellita seedlings from stem cutting was greater in terms of root distribution compared to propagation by seeds at the nursery stage, and 50 kg N ha-1 was the optimal nitrogen concentration level from the considered levels to be applied to the E. pellita seedlings. The present study therefore provides more information and understanding on E. pellita for forest plantation companies in producing plant materials using stem cutting in a cost-effective and efficient manner. This would help the forest plantation companies in planning appropriate agronomic management in the future.

Temporal variations in the rooting ability of cuttings of Populusbalsamifera and Salixplanifolia from natural clones–populations of subarctic Quebec

1993 ◽  
Vol 23 (12) ◽  
pp. 2603-2608 ◽  
Author(s):  
Gilles Houle ◽  
Patrice Babeux
Keyword(s):  
Root Length ◽  
Adventitious Roots ◽  
Growing Season ◽  
Temporal Variations ◽  
Bud Break ◽  
Root Number ◽  
Rooting Ability ◽  
Coefficients Of Variation ◽  
Site Restoration ◽  
Great Root

Temporal variations in the rooting ability of cuttings from five clones of Populusbalsamifera L. and five populations of Salixplanifolia Pursh from the Great Whale River valley in subarctic Quebec were determined. Cuttings were sampled monthly from May through October and rooted in a greenhouse. Root number and length of the longest root per cutting were determined 35 days after planting. There were significant variations among the six sampling dates in the rooting potential of cuttings of both species. A higher percentage of cuttings formed adventitious roots in May and June before or shortly after bud break than later, during the growing season; root number and length followed a similar trend. There was an increase in the rooting ability of cuttings of both species towards the fall period. Salixplanifolia produced more roots per cutting than P. balsamifera early in the season (i.e., May and June), but later in the season the differences between the two species were not great; root length showed no such trend. Differences among clones–populations in the rooting potential of cuttings were large for both species. Coefficients of variation for root number were lower in spring than later, during the growing season, for both P. balsamifera and S. planifolia. Seasonal trends in coefficients of variation for root length were not as evident as for root number. These results have significant implications for site restoration in the Subarctic. To optimize the rooting ability of cuttings and minimize the differences among clones–populations in rooting potential, cuttings should be sampled early in the season before bud break or shortly thereafter.

The relation between initial root length and subsequent growth in zea mays seedlings

PROTOPLASMA ◽  
1931 ◽  
Vol 12 (1) ◽  
pp. 190-195 ◽  
Author(s):  
Frederick S. Hammett ◽  
Jane Anderson ◽  
Elizabeth Justice
Keyword(s):  
Zea Mays ◽  
Root Length ◽  
Subsequent Growth ◽  
Initial Root

The genetic architecture of nodal root number in maize

2018 ◽  
Vol 93 (6) ◽  
pp. 1032-1044 ◽  
Author(s):  
Zhihai Zhang ◽  
Xuan Zhang ◽  
Zhelong Lin ◽  
Jian Wang ◽  
Mingliang Xu ◽  
...  
Keyword(s):  
Genetic Architecture ◽  
Root Number ◽  
Nodal Root

Rectification of radial water flow in the hypodermis of nodal roots of Zea mays

1989 ◽  
pp. 157-163
Author(s):  
M. G. T. Shone ◽  
D. T. Clarkson
Keyword(s):  
Zea Mays ◽  
Water Flow ◽  
Nodal Roots
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