scholarly journals HIGH TEMPERATURE RESPONSE IN BEAN-PHYSIOLOGICAL CONSIDERATIONS.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1175f-1175
Author(s):  
Paul H. Li
Keyword(s):  
High Temperature ◽  
Selection Criterion ◽  
Temperature Response ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Reproductive Organs ◽  
Heat Injury ◽  
Hot Weather ◽  
Photosynthetic Activities ◽  
Post Stress

The common bean (Phaseolus vulgaris L.) is a heat-sensitive plant species in which excessive abscission of reproductive organs occurs during hot weather. This results in yield reductions, and, in extreme heat stress, plants produce few or no pods. We evaluated 74 bean genotypes in terms of leaf heat tolerance (HT) and leaf heat acclimation potential (HAP), as expressed by heat killing time (HKT), the time in minutes needed to cause a 50% electrolyte leakage from leaf tissue heated at 50°C Leaf HT is defined as the leaf HKT of plants without prior conditioning at 37°C day/night temperature and leaf HAP as the change in leaf HT following exposure of the plant to 37°C day/night for 24-h. Among 74 bean genotypes examined leaf HT ranged from 5 to 30 min HKT, whereas leaf HAP ranged from 35 to 130 min HKT. Positive significant correlations were observed between leaf HAP and post-stress performance in photosynthetic activities, plant dry weight, pod set, pod weight and yield among bean genotypes. Correlations, however, were not significant between leaf HT and post-stress performance.A relationship between heat resistance, consisting of the combination of HT and HAP, and heat injury is proposed. Interpretation of the differential amounts of heat injury among genotypes having different HAP, is discussed. We view leaf HT and leaf HAP as two distinguishable phenomena. We suggest that in breeding programs HAP may be the more important of the two, and should he evaluated as a selection criterion for improving crop performance in high temperature environments.

scholarly journals Heat-tolerant pepper cultivar exhibits high rates of chlorophyll, photosynthesis, stomatal conductance and transpiration in heat stress regime at fruit developing stage

2021 ◽  
pp. 5-9
Author(s):  
S. N. Rajametov ◽  
M. C. Cho ◽  
K. Lee ◽  
H. B. Jeong ◽  
E. Y. Yang
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Stomatal Conductance ◽  
Temperature Regime ◽  
Total Chlorophyll ◽  
Heat Injury ◽  
Heat Tolerant ◽  
Photosynthetic Activities ◽  
Pepper Cultivar ◽  
Pepper Plants

Relevance. Abiotic stress, as heat, significantly affect plant and floral organs growth and development, fruit set, productivity, the quality, and survival of crops. Heat injury occurs when plants are exposed to these temperatures for a long period of time. Depending on the intensity and duration of exposure to the high temperatures, photosynthesis, respiration, membrane integrity, water relations and the hormone balance of the plants may affected.Material and methods. In this study used the commercial pepper cultivar “NW Bigarim” (HT37) released in South Korea and accessions “Kobra” (HT1) and “Samchukjaere” (HT7) selected as heat tolerant and susceptible, respectively. Total chlorophyll index and photosynthetic activities measured using a SPAD meter (Konica, Japan) and portable photosynthesis measurement system (LI-6400, LI-COR Bioscience, Lincoln, NE, USA), respectively.Results. To evaluate the positive effects of high temperature regime (40/28°C day/night, 14/10-h light/dark cycle) on the response of photosynthetic parameters in pepper plants with different heat susceptibility, we measured the total chlorophyll content (CHL) and photosynthetic activities such as photosynthesis (Pn), stomatal conductance to H2O (Gs) and transpiration rate (Tr) in a heat-tolerant (HT1) and -susceptible cultivars (HT7) in comparison with released cultivar (HT37) at fruit development stage. Heat-tolerant cultivars showed higher and more stable index of the CHL, Pn, Gs and Tr than those in heat-sensitive cultivars for 14 days of heat treatment (HT) period. However, the initial index of Pn, Gs and Tr showed significant alteration among pepper plants regardless of thermotolerance rate before HT on day 0 and day 7 after recovery at normal treatment condition (NT) except for CHL, meaning that plants response to high temperature regime is different from that in normal condition. These results suggest that constant high rates of Pn, Gs and Tr as well as of CHL in heat stress condition periods confer to avoid from heat injury during reproductive growth stages.

Photosynthesis and assimilate distribution in relation to yield of cassava grown in controlled environments

1976 ◽  
Vol 54 (12) ◽  
pp. 1322-1331 ◽  
Author(s):  
J. D. Mahon ◽  
S. B. Lowe ◽  
L. A. Hunt
Keyword(s):  
High Temperature ◽  
Root Respiration ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Root Weight ◽  
Manihot Esculenta Crantz ◽  
Controlled Environments ◽  
Net Assimilation ◽  
Plant Respiration

Cassava (Manihot esculenta Crantz) plants were grown for 52 weeks in controlled-environment growth rooms with day/night (14/10 h) temperatures of 29/24 °C and 24/19 °C. Plants were sampled for growth analysis at monthly intervals for 36 weeks and at 52 weeks. At intervals the photosynthetic CO2 uptake by leaf parts and the respiration were measured in situ by using infrared CO2 analysis.The growth rate at both temperatures was directly related to the product of leaf photosynthesis and total leaf area, and the decreasing net assimilation rate of the high-temperature plants was reflected in the declining mean photosynthetic rates of the leaf tissue. The rate of photosynthetic CO2 uptake was between 9 and 18 mg dm−2 h−1, depending on leaf position.During the early stages of growth, the relationship between root weight and total weight was unaffected by temperature. As the plants increased in size, the proportion of dry matter in the roots increased in low-temperature plants but remained constant in high-temperature plants. The estimated plant respiration averaged 45% of the total assimilation. In high-temperature plants the root respiration was equivalent to 0.7% of the root dry weight per day and after 36 weeks the total root respiration exceeded the root growth.

Study on characteristics of schottky temperature detector based on metal/n-ZnO/n-Si structures

2020 ◽  
Vol 12 ◽  
Author(s):  
Fang Wang ◽  
Jingkai Wei ◽  
Caixia Guo ◽  
Tao Ma ◽  
Linqing Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Response ◽  
Large Temperature ◽  
Mems Devices ◽  
Temperature Range ◽  
Response Characteristics ◽  
High Temperature Measurement ◽  
Temperature Detector ◽  
Schottky Structure

Background: At present, the main problems of Micro-Electro-Mechanical Systems (MEMS) temperature detector focus on the narrow range of temperature detection, difficulty of the high temperature measurement. Besides, MEMS devices have different response characteristics for various surrounding temperature in the petrochemical and metallurgy application fields with high-temperature and harsh conditions. To evaluate the performance stability of the hightemperature MEMS devices, the real-time temperature measurement is necessary. Objective: A schottky temperature detector based on the metal/n-ZnO/n-Si structures is designed to measure high temperature (523~873K) for the high-temperature MEMS devices with large temperature range. Method: By using the finite element method (FEM), three different work function metals (Cu, Ni and Pt) contact with the n-ZnO are investigated to realize Schottky. At room temperature (298K) and high temperature (523~873K), the current densities with various bias voltages (J-V) are studied. Results: The simulation results show that the high temperature response power consumption of three schottky detectors of Cu, Ni and Pt decreases successively, which are 1.16 mW, 63.63 μW and 0.14 μW. The response temperature sensitivities of 6.35 μA/K, 0.78 μA/K, and 2.29 nA/K are achieved. Conclusion: The Cu/n-ZnO/n-Si schottky structure could be used as a high temperature detector (523~873K) for the hightemperature MEMS devices. It has a large temperature range (350K) and a high response sensitivity is 6.35 μA/K. Compared with traditional devices, the Cu/n-ZnO/n-Si Schottky structure based temperature detector has a low energy consumption of 1.16 mW, which has potential applications in the high-temperature measurement of the MEMS devices.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

High-temperature-adaptedAzospirillum brasilensestrains: growth and interaction response on associative nitrogen fixation, mineral uptake and yield of cheena (Panicum miliaceumL.) genotypes in calcareous soil

1988 ◽  
Vol 110 (2) ◽  
pp. 321-329 ◽  
Author(s):  
R. Rai
Keyword(s):  
Nitrogen Fixation ◽  
High Temperature ◽  
Calcareous Soil ◽  
Nitrogenase Activity ◽  
Dry Weight ◽  
Cross Resistance ◽  
Mineral Uptake ◽  
Associative Nitrogen Fixation ◽  
Seed Inoculation ◽  
Resistance To Penicillin

SummaryHigh-temperature-adapted strains RAU 1, RAU 2 and RAU 3 ofAzospirillum brasilenseC 7 were isolated from stepwise transfer to higher temperature (30 to 42 °C). One of the strains (RAU 1) showed more growth, greater nitrogenase and hydrogenase activities at 30 and 42 °C than parental and other temperature-adapted strains. This strain also showed growth and more nitrogenase activity from pH 6·5 to 8·0. Strain RAU 1 showed cross-resistance to penicillin (300/µg/ml) but not to streptomycin, kanamycin, viomycin and polymixin B at 30 and 42 °C. It was demonstrated in field plots in calcareous soil that seed inoculation with RAU 1 enhanced mineral uptake of cheena. Inoculation with RAU 1 led to a significant increase in associative nitrogen fixation, dry weight of roots, grain and straw yield of cheena compared with the uninoculated control with or without applied N, but the effect of seed inoculation with high-temperature-adapted strains was variable with different genotypes of cheena.

scholarly journals Simultaneous Measurement of Temperature and Refractive Index Using High Temperature Resistant Pure Quartz Grating Based on Femtosecond Laser and HF Etching

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1028
Author(s):  
Na Zhao ◽  
Qijing Lin ◽  
Kun Yao ◽  
Fuzheng Zhang ◽  
Bian Tian ◽  
...  
Keyword(s):  
Refractive Index ◽  
High Temperature ◽  
Femtosecond Laser ◽  
Optical Fiber ◽  
Temperature Response ◽  
High Sensitivity ◽  
Xrd Analysis ◽  
Refractive Index Sensor ◽  
Compact Structure ◽  
Fluid Analysis

The optical fiber temperature and refractive index sensor combined with the hollow needle structure for medical treatment can promote the standardization of traditional acupuncture techniques and improve the accuracy of body fluid analysis. A double-parameter sensor based on fiber Bragg grating (FBG) is developed in this paper. The sensor materials are selected through X-ray diffraction (XRD) analysis, and the sensor sensing principle is theoretically analyzed and simulated. Through femtosecond laser writing pure silica fiber, a high temperature resistant wavelength type FBG temperature sensor is obtained, and the FBG is corroded by hydrofluoric acid (HF) to realize a high-sensitivity intensity-type refractive index sensor. Because the light has dual characteristics of energy and wavelength, the sensor can realize simultaneous dual-parameter sensing. The light from the lead-in optical fiber is transmitted to the sensor and affected by temperature and refractive-index; then, the reflection peak is reflected back to the lead-out fiber by the FBG. The high temperature response and the refractive index response of the sensor were measured in the laboratory, and the high temperature characteristics of the sensor were verified in the accredited institute. It is demonstrated that the proposed sensor can achieve temperature sensing up to 1150 °C with the sensitivity of 0.0134 nm/°C, and refractive sensing over a refractive range of 1.333 to 1.4027 with the sensitivity of −49.044 dBm/RIU. The sensor features the advantages of two-parameter measurement, compact structure, and wide temperature range, and it exhibits great potential in acupuncture treatment.

Stability of Anthocyanin from Mulberry Extracts in Alginate Microspheres at High Temperature

2012 ◽  
Vol 506 ◽  
pp. 587-590 ◽  
Author(s):  
R. Yamdech ◽  
Pornanong Aramwit ◽  
Sorada Kanokpanont
Keyword(s):  
High Temperature ◽  
Sodium Alginate ◽  
Dry Weight ◽  
Flow Rates ◽  
Alginate Solution ◽  
Water Extracts ◽  
External Gelation ◽  
Mulberry Fruit ◽  
Total Anthocyanins ◽  
Mulberry Fruits

The aim of this study was to investigate stabilities of anthocyanins from mulberry fruits extracts in alginate microspheres. The total anthocyanins contents measured from water extracts of mulberry fruits (Chiangmai/Jul cultivars) were at 10.46±0.51 mg/g DW and 15.31±0.86 mg/g DW (Chiangmai/Korat cultivars). At high temperature the extracts lost their anthocyanin contents to 52%wt (at 100°C for 5 hour) and 73%wt (at 121°C for 20 min). Alginate microspheres were prepared using external gelation methods. Sodium alginate solution (2.5%w/v) was sprayed into CaCl2solution (0.1M) through a nozzle at N2flow rates of 20 L/min. The average bead sizes were at 342.03±3.21µm. Anthocyanins loading on alginate microspheres were at 2.283±0.15 mg/g dry weight. At 80(10h), 100(5h) and 121°C(20min), Anthocyanins retention were at 91%wt, 82%wt and 89%wt, respectively. Adsorption of anthocyanins from mulberry fruit extracts on alginate microspheres resulted in a greater stability at high temperature than that of the free anthocyanins.

scholarly journals Responses of Tomato to Potassium Rates in a Calcareous Soil

HortScience ◽  
2017 ◽  
Vol 52 (5) ◽  
pp. 764-769 ◽  
Author(s):  
Qiang Zhu ◽  
Monica Ozores-Hampton ◽  
Yuncong Li ◽  
Kelly Morgan ◽  
Guodong Liu ◽  
...  
Keyword(s):  
Calcareous Soil ◽  
Plant Biomass ◽  
Winter Season ◽  
Calcareous Soils ◽  
Leaf Tissue ◽  
Dry Weight ◽  
The United States ◽  
Ammonium Bicarbonate ◽  
Soluble Solids ◽  
Postharvest Quality

Florida produces the most vegetables in the United States during the winter season with favorable weather conditions. However, vegetables grown on calcareous soils in Florida have no potassium (K) fertilizer recommendation. The objective of this study was to evaluate the effects of K rates on leaf tissue K concentration (LTKC), plant biomass, fruit yield, and postharvest quality of tomatoes (Solanum lycopersicum L.) grown on a calcareous soil. The experiment was conducted during the winter seasons of 2014 and 2015 in Homestead, FL. Potassium fertilizers were applied at rates of 0, 56, 93, 149, 186, and 223 kg·ha−1 of K and divided into preplant dry fertilizer and fertigation during the season. No deficiency of LTKC was found at 30 days after transplanting (DAT) in both years. Potassium rates lower than 149 kg·ha−1 resulted in deficient LTKC at 95 DAT in 2014. No significant responses to K rates were observed in plant (leaf, stem, and root combined) dry weight biomass at all the sampling dates in both years. However, at 95 DAT, fruit dry weight biomass increased with increasing K rates to 130 and 147 kg·ha−1, reaching a plateau thereafter indicated by the linear-plateau models in 2014 and 2015, respectively. Predicted from quadratic and linear-plateau models, K rates of 173 and 178 kg·ha−1 were considered as the optimum rates for total season marketable yields in 2014 and 2015, respectively. Postharvest qualities, including fruit firmness, pH, and total soluble solids (TSS) content, were not significantly affected by K rates in both years. Overall, K rate of 178 kg·ha−1 was sufficient to grow tomato during the winter season in calcareous soils with 78 to 82 mg·kg−1 of ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extracted K in Florida.

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