Physiology and metabolism of grafted bell pepper in response to low root-zone temperature

2019 ◽  
Vol 46 (4) ◽  
pp. 339 ◽  
Author(s):  
Moses Kwame Aidoo ◽  
Tal Sherman ◽  
Naftali Lazarovitch ◽  
Aaron Fait ◽  
Shimon Rachmilevitch
Keyword(s):  
Gas Exchange ◽  
Low Temperature ◽  
Root Zone ◽  
Dry Mass ◽  
Bell Pepper ◽  
Gas Chromatography Mass Spectrometry ◽  
Limiting Factor ◽  
Root Zone Temperature ◽  
Low Root Zone Temperature ◽  
Zone Temperature

Low temperature is a prominent limiting factor for tropical originated crops production in temperate regions, particularly during cool-season production. The diverse response of two rootstocks (Canon-sensitive and S103-tolerant to low root-zone temperature) was studied when exposed to aeroponically different temperature regimes at the root zone: constant low temperature of 14°C low root-zone temperature (LRZT), transient exposure to LRZT of 27–14−27°C and control temperature of 27°C. Gas exchange, shoot dry mass, and root morphology were measured. Shifts in central and secondary metabolite levels in the leaves and roots were examined by gas chromatography-mass spectrometry (GC-MS). Low root-zone temperature inhibited photosynthesis and transpiration of both grafted bell pepper plants; however, self-grafted Canon physiology was impeded to a greater extent compared with Canon grafted onto rootstock S103. Rootstock S103 demonstrated higher sink potential contributing to milder reduction of photosynthesis and transpiration during stress compared with self-grafted Canon. This reduction of gas exchange led to a significant reduction of root maximum length and root dry mass in self-grafted Canon in response to the stress at 14°C compared with Canon grafted onto rootstock S103. In response to stress, GC-MS metabolite profiling showed enhance metabolism in both cultivars’ leaves, as well as in the roots irrespective of the developmental stage of the plant. This evidence combined indicates enhance gas exchange and carbon assimilation when bell pepper is grafted on S103 under low root-zone temperature.

Effect of low root-zone temperature on nodule initiation in narrow-leafed lupin (Lupinus angustifolius L.)

2002 ◽  
Vol 53 (3) ◽  
pp. 355 ◽  
Author(s):  
Sally C. Peltzer ◽  
Lynette K. Abbott ◽  
Craig A. Atkins
Keyword(s):  
Low Temperature ◽  
Root Zone ◽  
Lupinus Angustifolius ◽  
Nodule Development ◽  
Culture Solution ◽  
Mineral N ◽  
Root Zone Temperature ◽  
Low Root Zone Temperature ◽  
Nodule Initiation ◽  
Zone Temperature

The effect of low root-zone temperature on nodulation of Lupinus angustifolius [L.] cv. Yandee was studied using glasshouse experiments in which the effects of temperature on nodule initiation and subsequent nodule development could be assessed separately. Low temperature (7 and 12˚C compared with 25˚C) reduced the growth of both uninoculated plants supplied with adequate mineral N and inoculated plants reliant on fixation alone for their N. However, even at 25˚C, growth of inoculated plants compared with plants supplied with mineral N was limited, and at lower temperatures nodulation was severely inhibited. The most sensitive stage to low root-zone temperature was nodule initiation and there appeared to be a critical temperature between 7 and 12˚C at which initiation did not take place. Increasing the number of bacteria in inocula (from 5 × 103 to 5 × 107 viable cells/mL) did not overcome inhibition. A number of diverse cultivars of L. angustifolius showed the same response as cv. Yandee. Low temperature inhibition of nodule initiation could be overcome by addition of culture solution collected from around the roots of symbioses established at 25˚C. The culture solutions were only effective if the roots at 25˚C were inoculated or, if collected from around uninoculated roots of plants grown with mineral N, they were first exposed to a Bradyrhizobium suspension and then sterilised before addition to cultures at low temperature. The data indicate that both plant and bradyrhizobial factors are required for nodule initiation and that exudation of plant factors at low root-zone temperature is insufficient to stimulate production of the nodulation factors from Bradyrhizobium. At 25˚C, the nodulation zone of lupin roots bore many fractures in the epidermis and showed a high frequency of free root cap border cells, as well as a distinct matrix of extracellular material. These features were significantly reduced at 12˚C and essentially absent at 7˚C, indicating that at low temperature bacterial entry may be restricted.

scholarly journals Responses to High Root-zone Temperature Among Cultivars of Red Maple and Freeman Maple

1995 ◽  
Vol 13 (2) ◽  
pp. 82-85
Author(s):  
Lorna C. Wilkins ◽  
William R. Graves ◽  
Alden M. Townsend
Keyword(s):  
Root Zone ◽  
Acer Rubrum ◽  
Dry Mass ◽  
Stem Length ◽  
Red Maple ◽  
Third Order ◽  
Root Zone Temperature ◽  
Leaf Chlorophyll ◽  
Order Root ◽  
Zone Temperature

Abstract Two experiments were conducted to determine whether genotypes of red maple (Acer rubrum L.) and Freeman maple (A. x freemanii E. Murray) differ in responses to high root-zone temperature. During the first experiment, dry mass of ‘Franksred’, ‘October Glory’, and ‘Schlesinger’ red maple, ‘Indian Summer’ Freeman maple, and selections from Arkansas, Maine, and Wisconsin were similar at 24, 28, and 32C (75, 82, and 90F), but dry mass at 36C (97F) was only 22% of that at 28C (82F). ‘Autumn Flame’, ‘Franksred’, ‘October Glory’, and ‘Schlesinger’ red maple and ‘Indian Summer’ and ‘Jeffersred’ Freeman maple differed in responses to 34C (93F) during the second experiment. Stem length and plant dry mass were higher at 28C (82F) than at 34C (93F) for all cultivars except ‘Autumn Flame’ and ‘Jeffersred’, and the extent to which 34C (93F) decreased the length of the longest third-order root ranged from 50% for ‘Autumn Flame’ to 90% for ‘Indian Summer’. The higher root-zone temperature decreased transpiration by as little as 25% for ‘Jeffersred’ to as much as 89% for ‘Franksred’, and 34C (93F) reduced leaf chlorophyll content of only ‘Indian Summer’ and ‘Jeffersred’. These results indicate that ‘Franksred’ and ‘Indian Summer’ are relatively sensitive while ‘Autumn Flame’, ‘Jeffersred’, and ‘Schlesinger’ are relatively resistant to high root-zone temperature.

scholarly journals Numerical and Experimental Analyses on Root Zone Temperature in Aeroponic Cultivation Box

2020 ◽  
Vol 38 (4) ◽  
pp. 871-879
Author(s):  
Yahui Luo ◽  
Xiwen Yang ◽  
Pin Jiang
Keyword(s):  
Low Temperature ◽  
Energy Efficient ◽  
Cfd Simulation ◽  
Root Zone ◽  
Single Point ◽  
Maximum Error ◽  
Root Zone Temperature ◽  
Different Temperatures ◽  
Nutrient Solutions ◽  
Zone Temperature

Vegetable growth requires a relatively stable environment for the root zone. If the temperature in root zone environment is optimal, the aeroponic cultivation will be energy-efficient, and the aeroponic vegetables will grow well at high, normal, or low temperature. By computational fluid dynamics (CFD), this paper numerically simulates the root zone temperature of lettuce in the aeroponic cultivation box, after the box was sprayed with nutrient solutions of different temperatures. Then, the root zone environments of aeroponic lettuce were monitored through experiments at three different temperatures: high temperature, normal temperature, and low temperature. Through comparison, it was learned that the error between the simulated and measured values at each point was smaller than 1.35℃; the maximum error at a single point was within 7.4%; overall, the mean relative error was merely 5.8%. The results prove that the proposed CFD simulation model is reasonable and effective. Our research provides a theoretical reference for optimizing the root zone temperature, regulating the spray of nutrient solutions at different temperatures, and building an energy-efficient efficient aeroponic cultivation system.

scholarly journals Propagation Daily Light Integral and Root-Zone Temperature Influence Rooting of Single-internode Pennisetum ×advena Culm Cuttings

HortScience ◽  
2018 ◽  
Vol 53 (2) ◽  
pp. 176-182 ◽  
Author(s):  
W. Garrett Owen ◽  
Roberto G. Lopez
Keyword(s):  
Root Zone ◽  
Biomass Accumulation ◽  
Dry Mass ◽  
Naphthaleneacetic Acid ◽  
Root Zone Temperature ◽  
Daily Light Integral ◽  
Pennisetum Setaceum ◽  
The Impact ◽  
Light Integral ◽  
Zone Temperature

Crown division, tissue culture, and culm cuttings are methods for propagating purple fountain grass [Pennisetum ×advena Wipff and Veldkamp (formerly known as Pennisetum setaceum Forsk. Chiov. ‘Rubrum’)]. However, propagation by culm cuttings is becoming an economically attractive method for quick liner production. Our objective was to quantify the impact of propagation daily light integral (PDLI) and root-zone temperature (RZT) on root and culm development of single-internode purple fountain grass culm cuttings. Before insertion into the rooting substrate, cuttings were treated with a basal rooting hormone solution containing 1000 mg·L−1 indole-3-butyric acid (IBA) + 500 mg·L−1 1-naphthaleneacetic acid (NAA). The cuttings were placed in a glass-glazed greenhouse with an air temperature of 23 °C and benches with RZT set points of 21, 23, 25, or 27 °C. PDLIs of 4 and 10 mol·m−2·d−1 (Expt. 1) or 8 and 16 mol·m−2·d−1 (Expt. 2) were provided. After 28 d, culm and root densities (number) increased as the RZT increased from 21 to 27 °C, regardless of PDLI during Expt. 1. Compared with 4 mol·m−2·d−1, a PDLI of 10 mol·m−2·d−1 generally resulted in the greatest root biomass accumulation. For example, as PDLI increased from 4 to 10 mol·m−2·d−1, root dry mass increased by 105%, 152%, and 183% at RZTs of 21, 25, and 27 °C, respectively. In Expt. 2, as the RZT increased from 21 to 23 °C, root dry mass increased by 70% under a PDLI of 8 mol·m−2·d−1. However, root dry mass was similar among all RZTs under a PDLI of 16 mol·m−2·d−1. Our results indicate that single-internode culm cuttings of purple fountain grass can be most efficiently propagated under PDLIs of 8–10 mol·m−2·d−1 together with RZT set points of 23 to 25 °C for quick liner production.

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