scholarly journals Distinct impacts of air and root-zone temperatures on leaf and root features of cucumber seedlings: resource acquisition capacity, organ size and carbon-nitrogen balance

2018 ◽  
Author(s):  
Xiaozhuo Wang ◽  
Lihong Gao ◽  
Yongqiang Tian
Keyword(s):  
Nitrogen Balance ◽  
Root Zone ◽  
Absorption Capacity ◽  
Resource Acquisition ◽  
Relative Growth ◽  
C And N ◽  
Hydroponically Grown ◽  
Relative Root Length ◽  
N Acquisition ◽  
Relative Root

ABSTRACTBoth low air (Tair) and root-zone (Troot) temperatures can inhibit resource (e.g. carbon and nutrients) acquisition by leaves and roots through various aspects, such as morphology, biomass allocation and assimilation/absorption capacity. However, it is still ambiguous whetherTairandTrootinfluence carbon (C) and nutrient acquisition via the same approach. To this end, in this study, cucumber (Cucumis sativusL.) seedlings were hydroponically grown under treatments arranged in complete factorial combination of two levels ofTair(26/18°C and 20/12°C, day/night) and two levels ofTroot(19°C and 13°C, constant). In general, bothTairandTrootaffected leaf and root sizes mainly by regulating their morphology rather than biomass investment. Under lowTairconditions (20/18°C), elevatedTroot(compare 19°C versus 13°C) did not influence C acquisition, but increased nitrogen (N) acquisition mainly due to an increase in relative root length, resulting in decreased C : N acquisition ratio. However, under lowTrootconditions (13°C), elevatedTair(compare 26/18°C versus 20/12°C) enhanced both C and N acquisition mainly because of an increase of both C assimilation in leaves and N absorption by roots, resulting in relatively constant C : N acquisition ratio. In addition, theTairandTrootinteraction was mainly observed in relative growth rate and root growth-related variables. Our results infer thatTairandTroothave distinct impacts on resource acquisition and carbon-nitrogen balance in plants.

scholarly journals GROWTH AND N AND C METABOLITES OF TOMATO IN RESPONSE TO ROOTS WARM DURING THE DAY AND COLD AT NIGHT, OR VICE VERSA

HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 914C-914
Author(s):  
Yong-Zhan Ma ◽  
Martin P.N. Gent
Keyword(s):  
Root Zone ◽  
Plant Size ◽  
Mineral Elements ◽  
N Accumulation ◽  
Root Zone Temperature ◽  
Relative Growth ◽  
Free Sugars ◽  
C And N ◽  
Light Concentration ◽  
Zone Temperature

How are C and N metabolites affected by a root-zone temperature (RZT) in phase or out of phase with the photoperiod? Tomato (Lycopersicon esculentum Mill.) was grown with an air temperature of 20C, and RZT that was in phase with a 12-h photoperiod, 28C in the light and 12C in the dark, or out of phase, 12C in the light and 28C in the dark. Seedlings were grown in flowing solution containing 200 μm NO3 and excess amount of other mineral elements. The flow rate increased with plant size. After 8 days, plants were harvested at the end of the day and at the end of the night. The relative growth rate (day–1) was slightly greater for in-phase (0.19) than out-of-phase RZT (0.17) and less than that at a constant air and RZT of 24C (0.22). RZT affected N accumulation and partitioning of C and N metabolites. Cool roots contained more NO3 and free sugars than warm roots. Leaves had less NO3 in the light than in the dark, and NO3 in leaves of plants with an out-of-phase RZT was depleted in the light. Concentration of free amino acids and protein was greater and the amount of starch was less in leaves of plants with in-phase RZT.

scholarly journals UJI KETAHANAN TERHADAP ALUMINIUM DAN pH RENDAH PADA JAGUNG (Zea mays L) VARIETAS PIONEER DAN SRIKANDI SECARA IN VITRO

1970 ◽  
Vol 2 (3) ◽  
pp. 292-299
Author(s):  
Sri Romaito Dalimunthe ◽  
Abdullah Bin Arif ◽  
Irpan Badrul Jamal
Keyword(s):  
Acid Soil ◽  
Low Ph ◽  
Leaf Length ◽  
Al Toxicity ◽  
Marginal Land ◽  
Maize Productivity ◽  
Maize Varieties ◽  
Relative Root Length ◽  
Relative Root

One effort to increase maize productivity is by using marginal land for maize plantation. The marginal land that can be used is acid soil, but the problem are Al toxicity and low pH. To cope with these problems, cultivars having tolerance to Al toxicity and low pH are needed. Plant material used in this research were two maize varieties (Pioneer and Srikandi). Media selection is used there are 4 doses treatment aluminium (0, 250, 500 and 750 ppm AlCl3). All variables were observed except at the variable width of the leaf in this results showed that the treatment of aluminium (AlCl3) would not influence. Treatment combination Variety Srikandi and 250 ppm AlCl3 produces plant height, leaf length and leaf width is the shortest compared to other treatments. Variety Pioneer and Srikandi are suspected of varieties resistant aluminum and low pH values based on relative root length.

Ionic relations of Phillyrea latifolia L. plants during NaCl stress and relief from stress

1999 ◽  
Vol 77 (7) ◽  
pp. 969-975 ◽  
Author(s):  
Massimiliano Tattini ◽  
Riccardo Gucci
Keyword(s):  
Root Zone ◽  
Glandular Trichomes ◽  
Dry Weight ◽  
Nacl Stress ◽  
Selectivity Ratio ◽  
Relative Growth ◽  
Phillyrea Latifolia ◽  
Chloride Excretion ◽  
Mechanisms Of Salt Tolerance ◽  
Culture Growth

Two experiments were conducted on Phillyrea latifolia L. plants exposed to increasing NaCl concentrations at the root zone in hydroponic culture. Growth, ion fluxes within the plant, and rates of excretion by glandular trichomes were measured during both salinity stress and relief periods. The reduction in relative growth rate (RGR) of plants treated with 100 and 200 mM external NaCl was more marked when RGR was calculated on a fresh weight (FW) basis than on a dry weight (DW) basis. The RGR of previously salt-treated plants, expressed on a FW basis, did not differ from that of the controls over 5 weeks of relief from stress, whereas RGR calculated on a DW basis did not fully recover. Fluxes of Na+ and K+ appeared highly regulated. Sodium transport to the leaf of 100 mM salt-treated plants equalled that of the controls, whereas Na+ transport to the leaf was higher in 200 mM salt-treated plants. Selectivity ratio for K+ and Na+ transport to the leaf was increased by salt treatments. The exclusion ability for Cl- was markedly lower than that for Na+ at 300 and 400 mM external NaCl. The excretion of Na+ and Cl- by glandular trichomes was very low at all external NaCl concentrations and substantially higher in basal leaves than in apical leaves. These results indicate that in P. latifolia, mechanisms of salt tolerance operate by excluding sodium and maintaining high selectivity for uptake and transport of K+, whereas the excretion of toxic ions is of minor significance.Key words: chloride, excretion, growth, Phillyrea latifolia, potassium, sodium.

Effect of forest soil warming on the rate and temperature sensitivity of microbial C and N processes in a temperate mountain forest

2020 ◽  
Author(s):  
Carolina Urbina Malo ◽  
Ye Tian ◽  
Chupei Shi ◽  
Shasha Zhang ◽  
Marilena Heitger ◽  
...  
Keyword(s):  
Forest Soil ◽  
Temperature Sensitivity ◽  
Enzyme Activities ◽  
Thermal Acclimation ◽  
Soil Warming ◽  
Soil C ◽  
Soil Microbial ◽  
C And N ◽  
N Acquisition

<p>Despite the intensified efforts to understand the impacts of climate change on forest soil C dynamics, few studies have addressed the long term effects of warming on microbially mediated soil C and nutrient processes. In the few long-term soil warming experiments the initial stimulation of soil C cycling diminished with time, due to thermal acclimation of the microbial community or due to depletion of labile soil C as the major substrate for heterotrophic soil microbes. Thermal acclimation can arise as a consequence of prolonged warming and is defined as the direct organism response to elevated temperature across annual to decadal time-scales which manifest as a physiological change of the soil microbial community. This mechanism is clearly different from apparent thermal acclimation, where the attenuated response of soil microbial processes to warming is due to the exhaustion of the labile soil C pool.</p><p>The Achenkirch experiment, situated in the Northern Limestone Alps, Austria (47°34’ 50’’ N; 11°38’ 21’’ E; 910 m a.s.l.) is a long term (>15 yrs) soil warming experiment that has provided key insights into the effects of global warming on the forest soil C cycle. At the Achenkirch site, we have observed a sustained positive response of heterotrophic soil respiration and of soil CO<sub>2</sub> efflux to warming after nine years (2013), making it an appropriate setting for testing hypotheses about continued or decreasing warming effects at decadal scales. We collected soil from six warmed and six control plots in October 2019, from 0-10 cm and 10-20 cm depth, and incubated them at three different temperatures: ambient, +4, and +10 °C. We measured potential soil enzyme activities with fluorimetric assays, gross rates of protein depolymerization, N mineralization, and nitrification with <sup>15</sup>N isotope pool dilution approaches, and microbial growth, respiration, and C use efficiency (CUE) based on the <sup>18</sup>O incorporation in DNA and gas analysis.  Our preliminary results show that potential enzyme activities of aminopeptidase, N-acetylglucosaminidase, b-glucosidase, and acid phosphatase were stimulated by decadal soil warming by 1.7- to 3.5-fold, measured at the same i.e. ambient temperature. In contrast, the temperature sensitivity (Q10) remained unaltered between warmed and control soils for all enzyme activities (Q10=1.63-2.28), except for aminopeptidase where we observed a decrease in Q10 by 25% in warmed topsoils (0-10 cm). Aminopeptidase also had the highest temperature-sensitivity (Q10=2.39), causing a decrease of the enzymatic C: N acquisition ratio with warming. These results indicate an increasing investment in microbial N acquisition with warming. We will follow these trends based on results on gross rates of soil C and N processes, allowing to delineate decadal soil warming effects on soil microbial biogeochemistry and to understand their effect on the cross-talk between organic C and N cycling in calcareous forest soils.</p>

Establishment of evaluation procedure for soybean seed-flooding tolerance and its application to screening for tolerant germplasm sources

2017 ◽  
Author(s):  
Muhammad Jaffer Ali ◽  
Zheping Yu ◽  
Guangnan Xing ◽  
Tuanjie Zhao ◽  
Junyi Gai
Keyword(s):  
Germination Rate ◽  
Soybean Seed ◽  
Petri Dish ◽  
Dry Weight ◽  
Testing Procedure ◽  
Evaluation Procedure ◽  
Breeding Lines ◽  
Seedling Length ◽  
Relative Root Length ◽  
Relative Root

The experiments concluded 48hrs for germination testing as most appropriate stress duration. Using paper roll for recording the traits was the best method than petri dish and towel method. Among the traits relative germination rate (RGR), relative seedling length (RSL), relative root length (RRL), relative root fresh weight (RRFW) and relative root dry weight (RRDW) were proved to be flooding-responsive. RSL was chosen as the major seed-flooding indicator due to higher heritability (h2), genotypic coefficient of variation (GCV), correlation with other indicators and easier measuring procedure, while RRL was considered as the subsidiary indicator. Thus, the RSL in paper roll after 48hrs seed-flooding was recognized as standard seed-flooding testing procedure and used to evaluate breeding materials. Among the 11 cultivars, the superior seed-flooding-tolerant ones were M8206, NN1138-2 and ZXD, while ten best lines were evaluated from one hundred breeding lines.

Prediction of root zone water and nitrogen balance in an irrigated rice field using a simulation model

2014 ◽  
Vol 13 (3) ◽  
pp. 281-290 ◽  
Author(s):  
Ch. Jyotiprava Dash ◽  
A. Sarangi ◽  
D. K. Singh ◽  
A. K. Singh ◽  
Partha Pratim Adhikary
Keyword(s):  
Simulation Model ◽  
Nitrogen Balance ◽  
Rice Field ◽  
Root Zone ◽  
Irrigated Rice ◽  
Zone Water

scholarly journals Responses of six Brachiaria spp. accessions to root zone flooding

2008 ◽  
Vol 37 (5) ◽  
pp. 795-801 ◽  
Author(s):  
Luana Pabla de Souza Caetano ◽  
Moacyr Bernardino Dias-Filho
Keyword(s):  
Mass Production ◽  
Root Zone ◽  
Dry Mass ◽  
Brachiaria Brizantha ◽  
Gas Exchange Parameters ◽  
Relative Growth ◽  
Leaf Dry Mass ◽  
Leaf Elongation Rate ◽  
Relative Tolerance ◽  
Exchange Parameters

Some morphophysiological responses of Brachiaria brizantha cv. Marandu, cv. Piatã, cv. Arapoty, B163, B166 and B. ruziziensis R124 were compared in plants grown in pots, under flooded and well-drained conditions. Flooding reduced leaf elongation rate in all accessions. Leaf dry mass production was lower under flooding than in the control plants in all the studied accessions, except in cv. Piatã. Root dry mass production was reduced by flooding in cv. Marandu and in R124, while the proportion of biomass allocated to roots was reduced by flooding only in R124. It was not possible to detect significant differences between water regimes in the percentage of biomass allocated to culms and leaves for all accessions. Flooding decreased the number of tillers in cv. Marandu, in B163, B166 and in R124. Relative growth rate was decreased by flooding in cv. Marandu, in B163 and in R124. Flooding reduced gas exchange parameters in all accessions, but cv. Arapoty. The accessions tested differ in their relative tolerance to flooding. B. brizantha cv. Arapoty is considered the most tolerant. B. ruziziensis R124 is the most sensitive, followed by B. brizantha cv. Marandu. B. brizantha cv. Piatã, B163 and B166 are intermediate in flooding tolerance.

scholarly journals Microbiological properties of root zone of coconut grown in different soil series in Sri Lanka

CORD ◽  
2004 ◽  
Vol 20 (01) ◽  
pp. 34
Author(s):  
K.S.K.S. Fernando ◽  
N.A. Tennakoon ◽  
S. Widanapathirana
Keyword(s):  
Sri Lanka ◽  
Root Zone ◽  
Biological Properties ◽  
Soil Conditions ◽  
Soil Series ◽  
Climatic Zones ◽  
Microbiological Parameters ◽  
Identification Of Bacteria ◽  
C And N ◽  
Bacteria And Fungi

In Sri Lanka, coconut is cultivated under diverse soil conditions of varying fertility status available in different agro-climatic zones. Although chemical and physical characteristics in some of these soils are known, their biological properties are yet to be studied.   Hence the aim of this study was to determine the microbiological parameters in root zone of coconut grown in different soil series.  For this study, 20 different soil series in coconut growing area were analyzed for number of total bacterial and fungal colonies, identification of bacteria and fungi, biomass C and N; CO2 evolution and nitrogen mineralization.   The microbiological parameters varied with the soil series. The bacterial population densities   were   significantly   (p=0.001)   high   in  Ambakelle,   Kalpitiya,   Rathupasa   and Madampe soil series while the fungal colonies were significantly (p=0.001) high in Thambarawa, Pallama, Wilatawa and Ambakelle soil series.

scholarly journals High Pressure Sodium Irradiation and Infrared Radiation Accelerate Petunia Seedling Growth

1991 ◽  
Vol 116 (3) ◽  
pp. 435-438 ◽  
Author(s):  
David F. Graper ◽  
Will Healy
Keyword(s):  
High Pressure ◽  
Seedling Growth ◽  
Root Zone ◽  
Photon Flux ◽  
Growth Responses ◽  
Ambient Conditions ◽  
Fresh Weight ◽  
Photosynthetic Photon Flux ◽  
Ir Radiation ◽  
Relative Growth

The increase in photosynthetic photon flux (PPF) and plant temperature associated with supplemental high pressure sodium (HPS) irradiation were investigated during Petunia × hybrids Villm. `Red Flash' seedling development. Seedlings were treated for 14 days following emergence or 5 days after the first true leaf had expanded to 1 mm. Treatments consisted of continuous infrared (IR) radiation (Ambient + IR), ambient conditions with spill-over radiation from adjacent treatments (Ambient - IR), root zone heating to 19.5C (RZ Heat), continuous HPS irradiation at 167 μmol·s-1.m-2 PPF (HPS + IR) or continuous HPS irradiation at 167 μmol-1·m-2 PPF filtered through a water bath to remove IR (HPS - IR). Linear regression of natural log-transformed fresh weights indicated that increasing ambient PPF 53% and elevating plant temperature 4.3C (HPS + IR) increased seedling relative growth rate (RGR) by 45% compared with the control (Ambient - IR). Elevating plant temperature with + IR by 4.8C without supplementing PPF (Ambient + IR) increased RGR by 31% but failed to increase fresh weight (FW) above controls and resulted in etiolated plants that were unsuitable for transplanting. Once plants were removed from supplemental treatment and returned to ambient conditions, RGR for all treatments was similar. The increased FW promoted by IR and HPS treatments was maintained for up to 7 days after treatment. Therefore, the increased seedling growth responses observed with HPS treatment were due primarily to an increase in RGR during HPS treatment that is not sustained beyond treatment.

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