Root and Shoot Responses to Salt Stress in Jojoba (Simmondsia chinensis)

Author(s):  
Jhonathan Ephrath ◽  
Alon Ben-Gal ◽  
Amnon Bustan ◽  
Lina Zhao

<p>Salinity affects plant growth due to both osmotic and ionic stress. The root system is essential in defense mechanisms against salinity, particularly involving salt ion avoidance or exclusion. Jojoba (<em>Simmondsia chinensis</em>) displays significant resistance to salinity. In the present study, Jojoba was planted in 60-L plastic buckets containing perlite growth medium and were provided with eight distinct salinity levels using two operating tanks of final irrigation solutions. Response of Jojoba to salinity was measured in above ground parameters and in roots using minirhizotron access tubes and imaging analysis. Leaf phosphorous and potassium concentrations decreased with increasing salinity level while leaf manganese, calcium, sodium and chloride concentrations increased with irrigation salinity level. Jojoba plants were found to have high level of storage of salt minerals in leaves but without effects on photosynthesis or transpiration. Roots exhibited different distribution patterns under different salinity treatments. Root length density increased with increased salinity at each depth. Root number and root length increased over time. During spring, the plant growth was faster than winter. Root diameter decreased over time due to new root development. Time had a more significant effect on root length density than irrigation water salinity or soil depth. Root number and root length were not significantly affected by the salt treatments.</p>

2009 ◽  
Vol 60 (3) ◽  
pp. 280 ◽  
Author(s):  
Peter S. Searles ◽  
Diego A. Saravia ◽  
M. Cecilia Rousseaux

Several studies have evaluated many above-ground aspects of olive production, but essential root system characteristics have been little examined. The objective of our study was to evaluate root length density (RLD) and root distribution relative to soil water content in three commercial orchards (north-west Argentina). Depending on the orchard, the different drip emitter arrangements included either: (1) emitters spaced continuously at 1-m intervals along the drip line (CE-4; 4 emitters per tree); (2) 4 emitters per tree spaced at 1-m intervals, but with a space of 2 m between emitters of neighbouring trees (E-4); or (3) 2 emitters per tree with 4 m between emitters of neighbouring trees (E-2). All of the orchards included either var. Manzanilla fina or Manzanilla reina trees (5–8 years old) growing in sandy soils, although the specific characteristics of each orchard differed. Root length density values (2.5–3.5 cm/cm3) in the upper soil depth (0–0.5 m) were fairly uniform along the drip line in the continuous emitter (CE-4) orchard. In contrast, roots were more concentrated in the E-4 and E-2 orchards, in some cases with maximum RLD values of up to 7 cm/cm3. Approximately 70% of the root system was located in the upper 0.5 m of soil depth, and most of the roots were within 0.5 m of the drip line. For each of the three orchards, significant linear relationships between soil water content and RLD were detected based on 42 sampling positions that included various distances from the trunk and soil depths. Values of RLD averaged over the entire rooting zone and total tree root length per leaf area for the three orchards were estimated to range from 0.19 to 0.48 cm/cm3 and from 1.8 to 3.5 km/m2, respectively. These results should reduce the uncertainty associated with the magnitude of RLD values under drip irrigation as intensively managed olive orchards continue to expand in established and new growing regions.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1064e-1064 ◽  
Author(s):  
Edward F. Gilman ◽  
Michael E. Kane

Shoot and root growth were measured on Chinese juniper (Juniperus chinensis L.) Var. `Torulosa', `Sylvestris', `Pfitzeriana' and `Hetzii' 1, 2 and 3 years after planting into a simulated landscape from 10-liter black plastic containers. Mean diameter of the root system increased quadratically averaging 1, 2 m/year; whereas, mean branch spread increased at 0, 33 m/year, Three years after planting, root spread was 2, 75 times branch spread and roots covered an area 5.5 times that covered by the branches. Percentage of total root length located within the dripline of the plants remained fairly constant (71-77%) during the first 3 years following planting. Root length density per unit area increased over time but decreased with distance from the trunk. In the first 2 years after planting shoot weight increased faster than root `weight. However, during the third year after planting, the root system increased in mass and size at a faster rate than the shoots. Root length was correlated with root weight within root-diameter classes, Root spread and root area were correlated with trunk area, branch spread and crown area.


2020 ◽  
Vol 16 (2) ◽  
pp. 109-117
Author(s):  
Primarine R Tahapary ◽  
Herman Rehatta ◽  
Henry Kesaulya

Lettuce is a type of vegetable that is very popular with the people of Indonesia. It contains healthy nutrients including minerals, vitamins, antioxidants, potassium, iron, folate, carotene, vitamin C and vitamin E. Biostimulants has the ability to stimulate new root formation, improve plant root systems, increase the number of tillers, and increase yield. Biostimulant concentration and site of administration play a role in providing nutrients for the needs of lettuce plants. To obtain the right concentration and place of administration for the growth and yield of lettuce, the experiment was carried out using a 2-factor Randomized Block Design. The first factor was the concentration of biostimulants (K) with 6 levels of concentration including: K0 (without giving biostimulants), K1 (giving biostimulants at a concentration of 1 mL/L of water), K2 (giving of biostimulants at 2 mL/L of water), K3 (giving biostimulants at 3 mL/L of water). K4 (giving biostimulant at 4 mL/L water), K5 (giving biostimulant at 5 mL/L water). The second factor was the site of administration (T), namely: T1 (through the leaves) and T2 (through the soil). The interaction between biostimulant concentration and administration gave a very significant effect on leaf number, crop fresh weight, root length and root number. Biostimulant concentration (K) gave the percentage of plant growth in the variables of plant height (34.29%) and leaf area (47.34%). Place of administration (T) gave percentage of plant growth the variables of leaf area (21.08%) and root wet weight (0.52%). The interaction of biostimulant concentration and administration place (K x T) gave the percentages of plant growth variables of leaf number (15.5%), plant fresh weight (52.33%), root dry weight (2.30%), root length (16.53%), and root number (108.5%). The best treatment in this study was the provision of biostimulant at a concentration of 2 mL/L of water that was given through leaves. Keywords: administration place, biostimulant, concentration, growth and production, lettuce   ABSTRAK Selada merupakan jenis sayur yang sangat digemari oleh masyarakat Indonesia serta mengandung nutrisi yang sehat, yang meliputi mineral, vitamin, antioksidan, potassium, zat besi, folat, karoten, vitamin C dan vitamin E. Biostimulan mampu merangsang pembentukan akar baru, memperbaiki sistem perakaran tanaman, memperbanyak jumlah anakan, dan meningkatkan produksi tanaman. Konsentrasi biostimulan dan tempat pemberian merupakan interaksi yang berperan dalam menyediakan unsur hara bagi kebutuhan tanaman selada. Untuk memproleh konsentrasi dan tempat pemberian yang tepat bagi pertumbuhan dan produksi tanaman selada, dilakukan percobaan dengan menggunakan Rancangan Acak Kelompok 2 faktor. Faktor pertama adalah pemberian biostimulan (K) dengan 6 taraf konsentrasi meliputi: K0 (tanpa pemberian biostimulan), K1 (pemberian biostimulan dengan konsentrasi 1 mL/L air), K2 (pemberian biostimulan 2 mL/L air), K3 (pemberian biostimulan 3 mL/L air), K4 (pemberian biostimulan 4 mL/L air), K5 (pemberian biostimulan 5 mL/L air). Faktor kedua adalah tempat pemberian (T), yaitu: T1 (melalui daun) dan T2 (melalui tanah). Interaksi konsentrasi biostimulan berpengaruh sangat nyata terhadap variabel jumlah daun (helai), bobot segar tanaman (g), panjang akar (cm) dan jumlah akar (helai). Pada konsentrasi biostimulan (K) memberikan persentasepertumbuhan tanaman pada variabel tinggi tanaman (34,29%) dan luas daun (47,34%), Tempat pemberian (T) memberikan persentasepertumbuhan tanaman pada variabel luas daun (21,08%), bobot basah akar (0,52%), serta interaksi konsentrasi biostimulan dan tempat pemberian (KT) memberikan persentasepertumbuhan tanaman pada variabel jumlah daun (15,5%), bobot segar tanaman (52,33%), bobot kering akar (2,30%), panjang akar (16,53%), serta jumlah akar (108,5%). Perlakuan terbaik dalam penelitian ini adalah pemberian biostimulan konsentrasi 2 mL/L air dan diberikan melalui daun. Kata Kunci: biostimulan, konsentrasi, pertumbuhan dan produksi, selada, tempat pemberian,


2014 ◽  
Vol 24 (2) ◽  
pp. 209-221 ◽  
Author(s):  
Davie M. Kadyampakeni ◽  
Kelly T. Morgan ◽  
Arnold W. Schumann ◽  
Peter Nkedi-Kizza

Citrus (Citrus sp.) root length density (RLD) can help in understanding and predicting nutrient and water uptake dynamics. A study was conducted at two sites in Florida to investigate root and water distribution patterns among different irrigation and fertigation systems. The results over the 2 years showed that RLD was highest in the 0- to 15-cm soil depth and decreased with depth for all treatments at both sites. About 64% to 82% of the fibrous roots (<1 mm diameter) were concentrated in the irrigated zones of drip- and microsprinkler-irrigated trees and 18% to 36% were found in the nonirrigated zones at the Spodosol site (SS). At the Entisol site (ES), the RLD (<0.5 mm diameter) in the 0- to 15-cm depth soil for intensive microsprinkler or drip irrigation was 3- to 4-fold (nonirrigated zone) and 4- to 7-fold (irrigated zone) greater at the 0- to 15-cm soil depth than that for conventional irrigation system. The trees at SS were symptomatic for Huanglongbing (HLB; Candidatus Liberibacter asiaticus) in the second year, while those at ES were asymptomatic throughout the study. This might have limited the density and extent of root distribution at SS. The water contents remained either close to or slightly above the field capacity. The results showed higher RLD for intensive irrigation and fertigation practices in irrigated zones compared with conventional grower applications suggesting greater water and nutrient uptake potential for the former.


Author(s):  
Haroon Shahzad ◽  
Muhammad Iqbal ◽  
Safdar Bashir ◽  
Muhammad Farooq

The aggravating threat for today&rsquo;s agriculture is provision of food security to ever-escalating eating mouths utilizing scarce resources. Water scarcity is restraining humans to produce more from drops of water in place of gallons. Root is present at soil-plant interface and is main water extractor for plant. Its growth pattern varies as soil moisture conditions fluctuates. Present pot study consisting of two factors i.e. organic substrates (Farm manure, Poultry Manure and Molasses) and different water stress levels (50, 75, 100 and 125% of AWCs) using maize as test crop to assess their impact on different growth parameters (especially root growth). The experiment was conducted using CRD under factorial arrangement. Root length (44.55 cm), root fresh &amp; dry biomass (71.10 g and 24.30 g), root diameter (1.73 mm), root volume (0.24 cm3) and root length density (7.4 &times; 10&minus;3 cm cm&minus;3) were observed in farm manure treated pots at 75% AWC that was statistically indistinguishable from all other treatments at same water level and 100% water availability but eloquently greater than plants of all treatments at 50% and 125% available water contents. Shoot length, dry and fresh weights were observed greater in plants having 100% available moistures, that were at par with 75% water treated plants. Comparing treatments for all of the parameters in multivariate cluster analysis it was concluded that 75% available water contents produce almost similar to 100% along with the benefit of water security.


2014 ◽  
Vol 88 (5) ◽  
pp. 835-850 ◽  
Author(s):  
B. J. Wang ◽  
W. Zhang ◽  
P. Ahanbieke ◽  
Y. W. Gan ◽  
W. L. Xu ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1394
Author(s):  
Larícia Olária Emerick Silva ◽  
Raquel Schmidt ◽  
Gustavo Pereira Valani ◽  
Adésio Ferreira ◽  
Ana I. Ribeiro-Barros ◽  
...  

Coffee breeding based on root traits is important to identify productive genotypes under adverse environmental conditions. This study assessed the diversity of root traits in Coffea canephora and its correlation with plant height and crop yield. Undisturbed soil samples were collected down to 60 cm from 43 coffee genotypes, in which one of them was propagated by seed and all others by stem cutting. The roots were washed, scanned, and processed to quantify root length density, root volume, root superficial area, and root diameter. Additionally, plant height and crop yield were also assessed. Root length density ranged from 40 to 1411 mm cm−3, root volume from 6 to 443 mm3 cm−3, root superficial area from 61 to 1880 mm2 cm−3, and root diameter from 0.6 to 1.1 mm. Roots were concentrated in the topsoil (0–20 cm) for most genotypes. In deeper depths (30–60 cm), root length density, root volume, and root superficial area were higher in genotypes 14, 25, 31, and 32. Positive correlations were found between root traits and both plant height and crop yield. The results of this work may contribute to the overall cultivation of C. canephora, specially for crop breeding in adverse environmental conditions.


2018 ◽  
Vol 10 ◽  
pp. 01019
Author(s):  
Andrzej Żabiński ◽  
Urszula Sadowska

The objective of the study was determination of the variability of morphometry and comparison of the morphological structure of the root system in winter cultivars of spelt. Four spelt cultivars were used in the study: Frankencorn, Oberkulmer Rotkorn, Schwabenkorn and Ostro. The material for the study originated from a field experiment. The roots were collected using the soil core method to the depth of 30 cm, from the rows and inter-rows, then the roots were separated using a semi-automatic hydropneumatic scrubber. The cleaned roots were manually separated and scanned, obtaining their digital images. Image analysis was performed using the Aphelion computer software. In order to characterize the root system of the spelt cultivars included in the study, values of the following indexes were determined: root dry mass (RDM), root length density (RLD), specific root length (SRL), mean root diameter (MD). Based on the obtained results it was determined that the RDM, MD and RLD indexes in all spelt cultivars attain the highest values in the row, at the depth 0–5 cm.The highest value of the RDM and MD indexes characterized the root system of the Ostro cultivar at the depth 0–5 cm. The Oberkulmerrotkorn spelt cultivar was distinguished among the tested objects by the highest value of the SRL index.


2018 ◽  
Vol 48 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Doglas Bassegio ◽  
Marcos Vinicius Mansano Sarto ◽  
Ciro Antonio Rosolem ◽  
Jaqueline Rocha Wobeto Sarto

ABSTRACT Guar (Cyamopsis tetragonoloba L.) is commonly grown in arid lands, because of its high drought-tolerance. However, soil compaction may be a limiting factor to its growth. This study aimed to evaluate the guar growth, according to the soil penetration resistance (0.20 MPa, 0.33 MPa, 0.50 MPa, 0.93 MPa and 1.77 MPa, in a layer with depth between 0.15 m and 0.20 m), in a Rhodic Acrudox soil. The shoot and root dry mass, root length by the Q1/2 index (mechanical soil penetration resistance in which the root growth is reduced by 50 %) and root diameter were evaluated. The impairment of the guar shoot growth begins when the penetration resistance is greater than around 1 MPa. The soil compaction alters the distribution of guar roots in the soil profile, concentrating them in the 0.15 m layer, but it does not prevent roots from penetrating this layer and developing in depth. The root diameter increases in the compacted layer. A soil penetration resistance of up to 1.77 MPa does not influence the root length density below the compacted layer, as well as the total root length density of guar. Although the guar Q1/2 index is greater than 1.58, the shoot and root dry mass are impaired.


HortScience ◽  
2013 ◽  
Vol 48 (8) ◽  
pp. 1021-1026 ◽  
Author(s):  
Gilbert Miller ◽  
Ahmad Khalilian ◽  
Jeffrey W. Adelberg ◽  
Hamid J. Farahani ◽  
Richard L. Hassell ◽  
...  

Delineating the depth and extent of the watermelon [Citrullus lanatus (Thumb.) Matsum. & Nak.] root zone assists with proper irrigation management and minimizes nutrient leaching. The objective of this 3-year field study was to measure root distribution and root length density of watermelon (cv. Wrigley) grafted on two different rootstocks (Lagenaria siceraria cv. ‘FR Strong’ and Cucurbita moschata × Cucurbita maxima cv. Chilsung Shintoza) and grown under three soil moisture treatments. Irrigation treatments tested were: no irrigation (NI), briefly irrigated for fertigation and early-season plant establishment; minimally irrigated (MI), irrigated when soil moisture in top 0.30 m of soil fell below 50% available water capacity (AWC); well irrigated (WI), irrigated when soil moisture in top 0.30 m of soil fell below 15% (AWC). Root length density (RLD) was measured from 75-cm-deep soil cores at two locations three times per growing season and a third location at the end of the season. Cores 1 and 2 sample locations were 15 cm to the side of each plant: Core 1 on the same side as the drip tape and Core 2 on the opposite side. At the end of the season, Core 3 was taken 15 cm outside of the bed in bare ground. RLD was significantly greater in the 0- to 30-cm soil depth and dropped dramatically below 30 cm; it was not significantly affected by irrigation treatment or rootstock. Core 1, next to the drip tape, had greater RLD than Core 2, 30 cm from drip tape, but only at the later sampling dates. Roots were found in Core 3 at all depths, but the RLD was significantly less than that measured in Cores 1 and 2. These findings suggest that the effective root zone depth for watermelon is 0 to 30 cm and that the particular scion/rootstock combinations tested in this study do not differ in root system size or location.


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