scholarly journals In situ Root Phenotypes of Cotton Seedlings Under Phosphorus Stress Revealed Through RhizoPot

2021 ◽  
Vol 12 ◽  
Author(s):  
Zichen Zhang ◽  
Lingxiao Zhu ◽  
Dongxiao Li ◽  
Nan Wang ◽  
Hongchun Sun ◽  
...  
Keyword(s):  
Growth Rate ◽  
Root Length ◽  
Root Length Density ◽  
Root Hairs ◽  
Specific Root Length ◽  
Dry Weight ◽  
P Deficiency ◽  
Branch Density ◽  
P Absorption

Phosphorus (P) deficiency is a common challenge in crop production because of its poor mobility through the soil. The root system plays a significant role in P absorption from the soil and is the initial indicator of low P levels. However, the phenotypic dynamics and longevity of cotton roots under P stress remain unknown. In this study, RhizoPot, an improvised in situ root observation device, was used to monitor the dynamics of root phenotypes of cotton seedlings under P-deficient (PD) and P-replete (PR) conditions. Low P stress reduced P absorption and accumulation in the roots, leading to low dry weight accumulation. Cotton seedlings responded to low P stress by increasing the number of lateral roots, specific root length, branch density, root length density, and length of root hairs. Additionally, the life span of root hairs was prolonged. Low P stress also reduced the average diameter of roots, promoted root extension, expanded the root coverage area, and increased the range of P acquisition. Principal component analysis revealed that the net root growth rate, root length density, root dry weight, P absorption efficiency, average root hair length, and taproot daily growth significantly influenced the cotton root architecture. Collectively, these results show that low P stress reduces the net growth rate of cotton seedling roots and restricts plant growth. Plants respond to P deficiency by extending the life span of root hairs and increasing specific root length and lateral root branch density. This change in root system architecture improves the adaptability of plants to low P conditions. The findings of this study may guide the selection of cotton varieties with efficient P utilization.

Sex-specifically responsive strategies to phosphorus availability combined with different soil nitrogen forms in dioecious Populus cathayana

2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Specific Root Length ◽  
P Uptake ◽  
Root Tip ◽  
P Availability ◽  
P Deficiency ◽  
Populus Cathayana ◽  
Leaf P ◽  
P Supply

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.

Intrinsic capacity for nutrient foraging predicts critical external phosphorus requirement of 12 pasture legumes

2018 ◽  
Vol 69 (2) ◽  
pp. 174 ◽  
Author(s):  
Graeme A. Sandral ◽  
Rebecca E. Haling ◽  
Megan H. Ryan ◽  
Andrew Price ◽  
Wayne M. Pitt ◽  
...  
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Maximum Yield ◽  
Root Hairs ◽  
Specific Root Length ◽  
Trifolium Subterraneum ◽  
Legume Species ◽  
Pasture Legumes ◽  
Phosphorus Requirement ◽  
Pasture Legume

The mainstream pasture legume species such as Trifolium subterraneum, T. repens and annual Medicago spp. used in the temperate pasture systems of southern Australia have high critical external requirements for phosphorus (P) (i.e. P required to achieve 90% of maximum yield). This work aimed to identify alternative pasture legume species that could be used in systems with lower P input. Shoot and root biomass of 12 species of pasture legume was measured in response to seven rates of P applied to the top 48 mm of soil in a pot experiment. Most species had maximum yields similar to T. subterraneum, but some required only one-third of the applied P to achieve this. The critical external P requirement of the species, ranked from lowest to highest, was as follows: Ornithopus compressus = O. sativus < Biserrula pelecinus < T. michelianum = T. vesiculosum = T. glanduliferum < T. hirtum = Medicago truncatula = T. purpureum = T. incarnatum < T. spumosum = T. subterraneum. An ability to maximise soil exploration through a combination of high root-length density, high specific root length and long root hairs (i.e. a large specific root-hair-cylinder volume) was associated with a low critical external P requirement. The results indicate that Ornithopus spp. could be used to achieve productive, low P-input pasture systems.

scholarly journals Root Phenotyping for Drought Tolerance: A Review

Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 241 ◽  
Author(s):  
Allah Wasaya ◽  
Xiying Zhang ◽  
Qin Fang ◽  
Zongzheng Yan
Keyword(s):  
Drought Tolerance ◽  
Crop Yield ◽  
Root Length ◽  
Root Length Density ◽  
Canopy Temperature ◽  
Specific Root Length ◽  
Root Traits ◽  
Three Dimensions ◽  
Invasive Approach ◽  
Root Phenotyping

Plant roots play a significant role in plant growth by exploiting soil resources via the uptake of water and nutrients. Root traits such as fine root diameter, specific root length, specific root area, root angle, and root length density are considered useful traits for improving plant productivity under drought conditions. Therefore, understanding interactions between roots and their surrounding soil environment is important, which can be improved through root phenotyping. With the advancement in technologies, many tools have been developed for root phenotyping. Canopy temperature depression (CTD) has been considered a good technique for field phenotyping of crops under drought and is used to estimate crop yield as well as root traits in relation to drought tolerance. Both laboratory and field-based methods for phenotyping root traits have been developed including soil sampling, mini-rhizotron, rhizotrons, thermography and non-soil techniques. Recently, a non-invasive approach of X-ray computed tomography (CT) has provided a break-through to study the root architecture in three dimensions (3-D). This review summarizes methods for root phenotyping. On the basis of this review, it can be concluded that root traits are useful characters to be included in future breeding programs and for selecting better cultivars to increase crop yield under water-limited environments.

scholarly journals Shallow Substrates Support the Growth of Contrasting Plant Types Installed in Irrigated, Arid-Climate Green Roofs1

2017 ◽  
Vol 35 (4) ◽  
pp. 146-155
Author(s):  
Lauren Forrest ◽  
Rachel Gioannini ◽  
Dawn M. VanLeeuwen ◽  
Rolston St. Hilaire
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Dry Weight ◽  
Green Roofs ◽  
Greenhouse Experiment ◽  
Outdoor Environment ◽  
Arid Climate ◽  
Evaporative Demand ◽  
Design Factor ◽  
Substrate Depth

Abstract Extreme evaporative demand makes substrate depth a critical design factor in arid-climate green roofs. The objective of this study was to determine whether a shallow irrigated substrate could support the growth of hens and chicks (Sempervivum calcareum L.) and iceplant [Delosperma nubigenum (Hook.f.) L.Bolus] in an arid environment. First, an experiment was conducted in the greenhouse that established that plants survived in 10 cm (3.9 in), 15 cm (5.9 in), and 20 cm (7.9 in) substrate depths, which then lead to a second experiment in an outdoor environment. The substrate was heat-expanded clay:sand:worm castings (6:3:1, by volume) in a greenhouse experiment and heat-expanded clay:zeolite:worm castings (6:3:1, by volume) in an outdoor experiment. In the greenhouse experiment, deep root length density (RLD) was significantly greater in the 10 cm-deep (3.9 in) substrate, while outdoors, deep RLD was highest for plants grown in the 15 cm-deep (5.9 in) substrate. Outdoors, iceplant had significantly greater mean coverage and shoot dry weight than hens and chicks. Lack of significant differences in quality and coverage due to substrate depth, coupled with higher RLD in the 10 cm (3.9 in) and 15 cm (5.9 in) depths in both experiments provides evidence that shallow irrigated substrates support the growth of both taxa. Index words: iceplant, hens and chicks, plant coverage, root length density, quality, zeolite, heat expanded clay. Species used in this study: hens and chicks (Sempervivum calcareum L.); iceplant [Delosperma nubigenum (Hook.f.) L. Bolus].

scholarly journals Above and Belowground Growth of Corymbia maculata in a Constructed Soil: The Effect of Profile Design and Organic Amendment

2010 ◽  
Vol 36 (1) ◽  
pp. 11-17
Author(s):  
Karen Smith ◽  
Peter May ◽  
Robert White
Keyword(s):  
Organic Matter ◽  
Root Length ◽  
Organic Amendment ◽  
Root Length Density ◽  
Dry Weight ◽  
Nutrient Status ◽  
Fertilizer Treatment ◽  
Coir Fiber ◽  
Growth Responses ◽  
Profile Design

Spotted gum (Corymbia maculata (Hook.) K.D. Hill & L.A.S. Johnson), a common street tree in southern Australian cities, was used to assess growth responses to variations in profile design and organic amendment of constructed soils. Aboveground growth responses were total stem dry weight and foliar nutrient content. The belowground response was root length density. Soil profiles were constructed of sand, amended with either coir fiber, composted biosolids or composted green waste, at rates of 0, 5, 10 or 20% by volume. The profiles were either layered, with a 150 mm (6 in) organic-amended surface layer, or uniform, with amendment of the entire profile. A single fertilizer treatment was applied to all profiles. Shoot dry weight was only affected by organic matter type with the greatest growth in sand amended with composted biosolids. Foliage P and K content were affected by amendment but foliage N was not. Profile design affected root length density and distribution. Trees in uniform profiles had greater root length density, and a more uniform distribution of roots, especially with compost amendments. Above- and belowground growth increases are thought to be due to increased nutrient status resulting from organic matter mineralization.

scholarly journals Estimating the importance of maize root hairs in low phosphorus conditions and under drought

2019 ◽  
Vol 124 (6) ◽  
pp. 961-968 ◽  
Author(s):  
Florian Klamer ◽  
Florian Vogel ◽  
Xuelian Li ◽  
Hinrich Bremer ◽  
Günter Neumann ◽  
...  
Keyword(s):  
Root Hairs ◽  
Specific Root Length ◽  
P Uptake ◽  
Alkaline Soil ◽  
Secondary Effects ◽  
Short Root ◽  
P Deficiency ◽  
P Content ◽  
Low Phosphorus ◽  
P Supply

Abstract Background and Aims Root hairs are single-cell extensions of the epidermis that face into the soil and increase the root–soil contact surface. Root hairs enlarge the rhizosphere radially and are very important for taking up water and sparingly soluble nutrients, such as the poorly soil-mobile phosphate. In order to quantify the importance of root hairs for maize, a mutant and the corresponding wild type were compared. Methods The rth2 maize mutant with very short root hairs was assayed for growth and phosphorus (P) acquisition in a slightly alkaline soil with low P and limited water supply in the absence of mycorrhization and with ample P supply. Key Results Root and shoot growth was additively impaired under P deficiency and drought. Internal P concentrations declined with reduced water and P supply, whereas micronutrients (iron, zinc) were little affected. The very short root hairs in rth2 did not affect internal P concentrations, but the P content of juvenile plants was halved under combined stress. The rth2 plants had more fine roots and increased specific root length, but P mobilization traits (root organic carbon and phosphatase exudation) differed little. Conclusions The results confirm the importance of root hairs for maize P uptake and content, but not for internal P concentrations. Furthermore, the performance of root hair mutants may be biased by secondary effects, such as altered root growth.

scholarly journals Novel approaches to improving growth of pasture legumes at low phosphorus levels

2014 ◽  
Vol 76 ◽  
pp. 197-202
Author(s):  
S.N. Nichols ◽  
J.R. Crush
Keyword(s):  
White Clover ◽  
Root Length ◽  
Specific Root Length ◽  
Root Traits ◽  
Dry Weight ◽  
Root Weight ◽  
Soil P ◽  
P Acquisition ◽  
Shoot Dry Weight ◽  
Use Efficiency

Abstract Strategies to reduce the economic and environmental costs of phosphate (P) fertiliser use in mixed pastures through plant breeding are focussed on inefficiencies in the legume component. One approach is breeding within white clover for root systems with improved P acquisition properties. Selection for root length per unit root weight (specific root length, SRL) showed that higher SRL plants could retain more biomass in the above ground fraction with decreasing soil P, whereas plants with lower SRL diverted more biomass to roots. Back cross 1 (BC1) generation interspecific hybrids between white clover and a wild relative, Trifolium uniflorum L., may possess additional root traits influencing P acquisition. In glasshouse experiments, some T. repens × T. uniflorum hybrids, back-crossed to white clover, also exhibited higher shoot dry weight than their white clover cultivar parents at low nutrient supply levels and low to intermediate soil Olsen P. This, combined with low internal P concentrations, suggests some BC1 hybrids may be more tolerant of low soil P than white clover. Differences in both P acquisition ability and internal P use efficiency may contribute to the observed yield differences. There are good prospects for delivery of new-generation clover cultivars with improved phosphate use efficiency to New Zealand farmers. Keywords: phosphorus, white clover, Trifolium uniflorum, interspecific

scholarly journals 606 PB 246 Effect of planting density on root length distribution and mineral content in Y-shaped self rooted `Flordaprince' peach trees

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 519a-519
Author(s):  
T. Caruso ◽  
F.P. Marra ◽  
A. Motisi ◽  
D. Giovannini
Keyword(s):  
Root Length ◽  
Mineral Content ◽  
Root Length Density ◽  
Length Distribution ◽  
Dry Weight ◽  
Planting Density ◽  
Black Plastic ◽  
Old Trees ◽  
Peach Trees ◽  
Two Sides

Length and distribution of the roots of 2-year old cv. `Flordaprince' peach trees grown under polyethylene greenhouse were studied over a two year period. The self-rooted, micropropagated trees were spaced 4.9 m between the row and 70, 52 and 42 cm. along the row to obtain a density of 3000, 4000 and 5000 trees/ha respectively. Orchard was clean cultivated, mulched along the row with black plastic fabric 1 m wide, and drip fertigated. Soon after harvest, for each density, the root system of one tree was totally excavated and root length, distribution, dry weight and nutrients content were determined. Total root length per tree was negatively related to planting density in two-year old trees (470, 380 and 320 m/tree respectively for 3000, 4000 and 5000 trees/ha). The shallowest root systems were found at 5000 trees/ha density and their length was unchanged from year to year. Root length density, ranging from 220 to 250 m/m), was only slightly affected by spacing in the two years. The roots were evenly distributed between the two sides of the rows.

scholarly journals VESICULAR-ARBUSCULAR MYCORRHIZAL (VAM) FUNGI ALTER ROOT GROWTH OF PROSOPIS ALBA (CHILEAN MESQUITE) IN CONTAINERS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 688f-688
Author(s):  
Chris A. Martin ◽  
Jean C. Stutz ◽  
Robert W. Roberson
Keyword(s):  
Growth Medium ◽  
Root Length ◽  
Glomus Intraradices ◽  
Salt Lake ◽  
Salt Lake City ◽  
Specific Root Length ◽  
Dry Weight ◽  
Root Systems ◽  
Peat Moss ◽  
Vam Fungi

Effects of VAM fungal inoculum, Glomus intraradices Schenk & Smith, on the growth of Chilean mesquite in containers were investigated as part of a nursery container system for production of xeric trees. Seedling liners of Chilean mesquite were transplanted into 27-liter containers filled with a 3 pine bark : 1 peat moss : 1 sand medium. Before transplanting, 50% of the trees were band-inoculated at a depth of 8 to 12 cm below the growth medium surface with 35 g per container of Glomus intradices (Nutrilink, NPI, Salt Lake City, UT), approximately 1,000 spores g-1. All trees were top-dressed with 15 g Osmocote 18N-2.6P-9.9K (Grace-Sierra, Milpitas, CA) and 3 g Micromax (Grace-Sierra, Milpitas, CA) fertilizers and grown in a fiberglass greenhouse under 50% light exclusion. After 4 months, all inoculated tree root systems were colonized, and the percent infection was 47%. Noninoculated trees remained nonmycorrhizal. There were no differences in height, total shoot length, shoot dry weight, or root dry weight between inoculated and non-inoculated trees; however, total root length and specific root length of inoculated trees were less than those of noninoculated trees. These results suggest that the VAM fungi altered the root architecture of inoculated trees such that root systems of these trees had thicker roots with fewer fine roots elongating into the growth medium profile.

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