The contribution of lateral rooting to phosphorus acquisition efficiency in maize (Zea mays) seedlings

2004 ◽  
Vol 31 (10) ◽  
pp. 949 ◽  
Author(s):  
Jinming Zhu ◽  
Jonathan P. Lynch
Keyword(s):  
Growth Rate ◽  
Lateral Root ◽  
Root Respiration ◽  
Lateral Roots ◽  
Biomass Accumulation ◽  
Phosphorus Availability ◽  
Phosphorus Acquisition ◽  
Relative Growth ◽  
Phosphorus Stress ◽  
Low Phosphorus

Low soil phosphorus availability is a primary constraint for plant growth in many terrestrial ecosystems. Lateral root initiation and elongation may play an important role in the uptake of immobile nutrients, such as phosphorus, by increasing soil exploration and phosphorus solubilisation. The overall objective of this study was to assess the value of lateral rooting for phosphorus acquisition through assessment of the ‘benefit’ of lateral rooting for phosphorus uptake and the ‘cost’ of lateral roots in terms of root respiration and phosphorus investment at low and high phosphorus availability. Five recombinant inbred lines (RILs) of maize derived from a cross between B73 and Mo17 with contrasting lateral rooting were grown in sand culture in a controlled environment. Genotypes with enhanced or sustained lateral rooting at low phosphorus availability had greater phosphorus acquisition, biomass accumulation, and relative growth rate (RGR) than genotypes with reduced lateral rooting at low phosphorus availability. The association of lateral root development and plant biomass accumulation under phosphorus stress was not caused by allometry. Genotypes varied in the phosphorus investment required for lateral root elongation, owing to genetic differences in specific root length (SRL, which was correlated with root diameter) and phosphorus concentration of lateral roots. Lateral root extension required less biomass and phosphorus investment than the extension of other root types. Relative growth rate was negatively correlated with specific root respiration, supporting the hypothesis that root carbon costs are an important aspect of adaptation to low phosphorus availability. Two distinct cost–benefit analyses, one with phosphorus acquisition rate as a benefit and root respiration as a cost, the other with plant phosphorus accumulation as a benefit and phosphorus allocation to lateral roots as a cost, both showed that lateral rooting was advantageous under conditions of low phosphorus availability. Our data suggest that enhanced lateral rooting under phosphorus stress may be harnessed as a useful trait for the selection and breeding of more phosphorus-efficient maize genotypes.

NaCl salinity affects lateral root development in Plantago maritima

2004 ◽  
Vol 31 (8) ◽  
pp. 775 ◽  
Author(s):  
Michael Rubinigg ◽  
Julia Wenisch ◽  
J. Theo M. Elzenga ◽  
Ineke Stulen
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Root Length ◽  
Lateral Root ◽  
Lateral Roots ◽  
Third Order ◽  
Lateral Root Primordia ◽  
Relative Growth ◽  
Length Growth ◽  
Lateral Root Length

Root growth and morphology were assessed weekly in hydroponically-grown seedlings of the halophyte Plantago maritima L. during exposure to 0, 50, 100 and 200 mm NaCl for 21 d. Relative growth rate was reduced by 25% at 200 mm NaCl. The lower NaCl treatments did not affect relative growth rates. Primary and lateral roots responded differently to NaCl. While primary-root length increased at all NaCl concentrations, total lateral-root length increased at 50 and was not affected at 100 mm but was considerably reduced at 200 mm NaCl. NaCl concentrations of 50 and 100 mm, which had no effect on relative growth rate or total lateral-root length, severely affected root branching pattern in that the number of first, second and third order laterals was reduced. At 200 mm NaCl third order laterals were not formed at all. However, mean lateral-root length was increased at all NaCl concentrations and was highest at 200 mm NaCl. We conclude that the increase in total lateral-root length in plants at 50 and 100 mm NaCl was mainly caused by increased length growth, while the decrease in total lateral-root length at 200 mm was the consequence of inhibition of lateral root primordia and / or the activation of apical meristems rather than reduced length growth.

Genetic variation for adventitious rooting in response to low phosphorus availability: potential utility for phosphorusacquisition from stratified soils

2003 ◽  
Vol 30 (9) ◽  
pp. 973 ◽  
Author(s):  
Carter R. Miller ◽  
Ivan Ochoa ◽  
Kai L. Nielsen ◽  
Douglas Beck ◽  
Jonathan P. Lynch
Keyword(s):  
Lateral Root ◽  
Adventitious Roots ◽  
Root Systems ◽  
Adventitious Rooting ◽  
Phosphorus Availability ◽  
Root Density ◽  
Phosphorus Stress ◽  
Low Phosphorus ◽  
Basal Roots ◽  
Root Types

We hypothesized that adventitious roots may improve crop adaptation to low-phosphorus soils by enhancing topsoil foraging. In a tropical field study, phosphorus stress stimulated adventitious rooting in two phosphorus-efficient genotypes of common bean (Phaseolus vulgaris L.) but not in two phosphorus-inefficient genotypes. Although phosphorus availability had no consistent effects on the length or biomass of whole root systems, it had differential effects on adventitious, basal, and taproots within root systems in a genotype-dependent manner, resulting in increased allocation to adventitious roots in efficient genotypes. Adventitious roots had greater length per unit biomass than other root types, especially under phosphorus stress. Adventitious roots had less construction cost than basal roots, despite having similar tissue nitrogen content. Phosphorus stress reduced lateral root density, and adventitious roots had less lateral root density than basal roots. Lateral roots formed further from the root tip in adventitious roots compared with basal roots, especially under phosphorus stress. Field results were confirmed in controlled environments in solid and liquid media. Stimulation of adventitious rooting by phosphorus stress tended to be greater in wild genotypes than in cultivated genotypes. We propose that adventitious rooting is a useful adaptation to low phosphorus availability, because adventitious roots explore topsoil horizons more efficiently than other root types.

The utility of phenotypic plasticity of root hair length for phosphorus acquisition

2010 ◽  
Vol 37 (4) ◽  
pp. 313 ◽  
Author(s):  
Jinming Zhu ◽  
Chaochun Zhang ◽  
Jonathan P. Lynch
Keyword(s):  
Phenotypic Plasticity ◽  
Root Hair ◽  
Root Respiration ◽  
Root Hairs ◽  
Controlled Environment ◽  
P Availability ◽  
Hair Length ◽  
Phosphorus Acquisition ◽  
Root Hair Length ◽  
Low Phosphorus

Root hairs are subcellular protrusions from the root epidermis that are important for the acquisition of immobile nutrients such as phosphorus (P). Genetic variation exists for both root hair length and the plasticity of root hair length in response to P availability, where plasticity manifests as increased root hair length in response to low P availability. Although it is known that long root hairs assist P acquisition, the utility of phenotypic plasticity for this trait is not known. To assess the utility of root hair plasticity for adaptation to low phosphorus availability, we evaluated six recombinant inbred lines of maize (Zea mays L.) with varying root hair lengths and root hair plasticity in a controlled environment and in the field. Genotypes with long root hairs under low P availability had significantly greater plant growth, P uptake, specific P absorption rates and lower metabolic cost-benefit ratios than short-haired genotypes. Root hair length had no direct effect on root respiration. In the controlled environment, plastic genotypes had greater biomass allocation to roots, greater reduction in specific root respiration and greater final biomass accumulation at low phosphorus availability than constitutively long-haired genotypes. In the field study, the growth of plastic and long-haired genotypes were comparable under low P, but both were superior to short-haired genotypes. We propose that root hair plasticity is a component of a broader suite of traits, including plasticity in root respiration, that permit greater root growth and phosphorus acquisition in low P soils.

scholarly journals Biomass Accumulation in the Fern Asplenium nidus avis (L) under Root Restriction

2020 ◽  
pp. 1-9
Author(s):  
A. Pagani ◽  
J. Molinari ◽  
E. Giardina ◽  
A. Di Benedetto
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Parameters ◽  
Biomass Accumulation ◽  
Dry Weight ◽  
Point Of View ◽  
Relative Growth ◽  
Net Assimilation ◽  
Root Restriction ◽  
Asplenium Nidus

Pot ornamental plant productivity is related to the environmental growth facilities but negatively affected by the pot root restriction syndrome. Most ferns showed a lower relative growth rate and long production cycles (24 months or more) for which growers use small pots to increase yield per unit area of greenhouse. The aim of this work was to analyze growth changes in response to different pot volume in plants of A. nidus avis spore-propagated under the hypothesis that it would play a role as an abiotic stress which decrease commercial productivity. Our results showed that the use of big pots increased fresh and dry weight and frond area (the main aesthetic trait). When growth parameters were performed, a higher the frond appearance rate (RLA), the frond area expansion (RLAE) and the frond thickness (SLA) were found in 1500 cm3 pot as well as the relative growth rate (RGR) and the net assimilation rate. The use of biggest pot for fern cropping stimulated biomass accumulation through a higher capacity to initiate and expand fronds, to increase photosynthetic rates and change photo assimilate partitioning which favor shoots. From the grower´s point of view, our results suggested that higher yields of A. nidus avis fern would be reached decreasing root restriction, that is, to use the biggest pot volume from the early transplant from plug trays.

Competitive ability of cowpea genotypes with different growth habit

Weed Science ◽  
2006 ◽  
Vol 54 (4) ◽  
pp. 775-782 ◽  
Author(s):  
Guangyao Wang ◽  
Milton E. McGiffen ◽  
Jeff D. Ehlers ◽  
Edilene C. S. Marchi
Keyword(s):  
Growth Rate ◽  
Competitive Ability ◽  
Growth Habit ◽  
Biomass Accumulation ◽  
Growing Season ◽  
Similar Reduction ◽  
Relative Growth ◽  
Use Efficiency ◽  
Common Purslane ◽  
Prostrate Growth

Growth habit is an important determinant of competitive ability in legume crops. Erect ‘Iron-Clay’ (IC), semi-erect ‘IT89KD-288’ (288), and prostrate ‘UCR 779’ (779) cowpea genotypes were planted with four densities of common sunflower or common purslane to determine which cowpea growth habit is more competitive to these weeds having markedly different statures. Both sunflower and purslane reduced cowpea relative growth rate (RGR) but at different phases of the growing season. Low-growing purslane had an effect in the earlier part of the season, and sunflower decreased cowpea RGR in the middle of growing season. RGR of genotype IC was the least affected and genotype 779 the most reduced by sunflower. Cowpea apparently compensated for early season purslane competition by increasing RGR after purslane flowering, with RGR for the IC genotype increasing the most and 779 increasing the least. All cowpea genotypes caused a similar reduction in sunflower biomass accumulation; but purslane biomass was most reduced by genotype IC and least affected by genotype 288. Erect genotype IC is more competitive due to its taller stature, greater height growth rate, and higher position of maximal leaf area density, despite a lower photosynthetic rate and light use efficiency than the other cowpea genotypes. Our results suggest that erect cowpea growth habit may be generally more competitive with weeds compared to semi-erect or prostrate growth habit.

scholarly journals Response to Phosphorus Availability during Vegetative and Reproductive Growth of Chrysanthemum: II. Biomass and Phosphorus Dynamics

1998 ◽  
Vol 123 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Conny W. Hansen ◽  
Jonathan Lynch
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Production Rate ◽  
Root Length ◽  
Shoot Growth ◽  
Biomass Accumulation ◽  
Shoot Biomass ◽  
Reproductive Growth ◽  
Relative Growth ◽  
Whole Plant

Whole-plant biomass accumulation, P dynamics, and root-shoot interactions during transition from vegetative to reproductive growth of `Coral Charm' chrysanthemum (Dendranthema ×grandiflorum Ramat.) (Zander, 1993) were investigated over a range of P concentrations considered to be deficient (1 μm), adequate (100 μm), and high (5 mm). In nondeficient plants, transition from vegetative to reproductive growth resulted in reduced relative growth rate and root and shoot biomass accumulation. Reproductive plants showed a higher commitment of the whole plant to the production of developing flowers than to leaves and roots, whereas, in vegetative plants, the highest component production rate was in leaves. This indicates changes in the source-sink relationships during transition from vegetative growth making developing flowers stronger sinks for photoassimilates than roots. Phosphorus allocated to developing flowers was predominantly lost from leaves. Phosphorus-deficient plants showed characteristic P-deficiency symptoms and favored root growth over shoot growth regardless of growth stage. Phosphorus availability in nondeficient plants affected root growth more than shoot growth. No substantial differences in shoot biomass production, relative growth rate, and CO2 assimilation rates were observed in adequate-P and high-P plants. However, the root component production rate, root to shoot ratio, root length ratio, specific root length, specific root area, root mass to leaf area ratio, and root respiration increased in adequate-P plants compared with high-P plants, which indicates that high root activity was maintained without affecting shoot biomass in buffered P conditions. Our results suggest that the high P concentrations used in many horticultural systems may have no benefit in terms of shoot growth and may actually be detrimental to root growth.

scholarly journals Biomass association in specimens and interspecific hybrids of tomatoes

2019 ◽  
Vol 42 ◽  
pp. e42806
Author(s):  
André Ricardo Zeist ◽  
Marcos Ventura Faria ◽  
Juliano Tadeu Vilela Resende ◽  
André Gabriel ◽  
Julio José Nonato ◽  
...  
Keyword(s):  
Growth Rate ◽  
Interspecific Hybrids ◽  
Dry Matter ◽  
Biomass Accumulation ◽  
F1 Hybrids ◽  
Wild Type ◽  
Relative Growth ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Net Assimilation

The objective of this study is to analyze the growth of wild species of tomato, of the cultivar Redenção and of the respective F1 hybrids of interspecific crossings. We evaluated six wild-type accessions (Solanum pimpinellifolium ‘AF 26970’, S. galapagense ‘LA-1401’, S. peruvianum ‘AF 19684’, S. habrochaites var. hirsutum ‘PI-127826’, S. habrochaites var. glabratum ‘PI-134417’, and S. pennellii ‘LA-716’) and the commercial cultivar Redenção (S. lycopersicum) together with their respective interspecific hybrids. In completely randomized blocks and plots subdivided by time (16, 28, 42, 56, 70, and 84 days after transplanting), we evaluated leaf area (LA), total dry matter (TDM), absolute growth rate (AGR), relative growth rate (RGR) and net assimilation rate (NAR). The distribution of assimilates in the different organs followed different patterns according to genotype. There was a greater accumulation of LA and TDM in the accessions ‘PI-127826’ and ‘PI-134417’ and in the hybrids ‘Redenção’ x ‘PI-127826’ and ‘Redenção’ x ‘PI-134417’. Due to a heterotrophic effect provided by the crossings, there were higher LA, TDM, AGR, RGR and NAR in hybrids than in parent plants. The accessions ‘PI-127826’ and ‘PI-134417’ presented a potential to be donor parents for obtaining tomatoes with a greater capacity of net assimilation and biomass accumulation.

The effects of combined nitrogen on growth, nodulation, and nitrogen fixation of black locust seedlings

1983 ◽  
Vol 13 (6) ◽  
pp. 1251-1254 ◽  
Author(s):  
Dane R. Roberts ◽  
Richard W. Zimmerman ◽  
Jeff W. Stringer ◽  
Stanley B. Carpenter
Keyword(s):  
Growth Rate ◽  
Nitrogen Fixation ◽  
Black Locust ◽  
Nitrogen Deficiency ◽  
Biomass Accumulation ◽  
Leaf Nitrogen ◽  
Sand Culture ◽  
Leaf Nitrogen Content ◽  
Fixation Rate ◽  
Relative Growth

Black locust (Robiniapseudoacacia L.) seedlings grown for 50 days in sand culture with 5 mM NH4NO3-supplemented nutrient solution had 74% lower nitrogen-fixation rates (acetylene reduction) than seedlings grown without nitrogen. Nodule activity was not affected by treatment, and differences in nitrogen fixation between treatments reflected decreased nodulation in seedlings grown with NH4NO3. Relative growth rate was approximately 3 times greater in seedlings supplied with NH4NO3, indicating maximum biomass accumulation cannot be supported by nitrogen fixation alone. Growth was positively correlated with the nitrogen-fixation rate in seedlings grown without nitrogen, but this correlation was not found in NH4NO3-treated seedlings. Leaf nitrogen content was less for seedlings grown in the nitrogen-free sand culture and observations suggested that a nitrogen deficiency in these seedlings restricted their growth.

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