Temperature Stress Conditions Research Articles

Exogenously Applied GA3 Enhances Morphological Parameters of Tolerant and Sensitive Cyclamen persicum Genotypes under Ambient Temperature and Heat Stress Conditions.

Cyclamen genus is part of the Primulaceae family consisting of 24 species widely cultivated as ornamental and medicinal plants. They also possess high plasticity in terms of adaptability to alternating environmental conditions. In this regard, the present study investigates the germination and morphological parameters of heat-tolerant and heat-sensitive Cyclamen persicum accessions in the presence of different GA3 solutions (0, 30, 70 and 90 mg/L) under ambient temperature and heat stress conditions. Heat-tolerant genotypes, mainly C3-Smartiz Victoria (6.42%), C15-Merengue magenta (6.47%) and C16-Metis silverleaf (5.12%) had the highest germination rate with 90 mg/L GA3 treatment compared with control. Regarding heat-sensitive genotypes, C11-Verano (5.11%) and C13-Metis Origami (4.28%) had the lowest values in mean germination time, along with the Petticoat genotypes C1 (73.3%) and C2 (80.0%) with a high germination percentage. Heat-tolerant genotypes positively responded to GA3 (70 and 90 mg/L) even under heat stress conditions, by their higher values in plant height, an ascending trend also seen in heat-sensitive genotypes under GA3 treatment (70 and 90 mg/L). According to the hierarchical clustering, several heat-tolerant genotypes showed peculiar behavior under heat stress conditions, namely C3 (Smartiz Victoria), C7 (Halios falbala) and C8 (Latinia pipoca) which proved to be susceptible to heat stress even under GA3 application, compared with the other genotypes which showed tolerance to higher temperatures. In the case of heat-sensitive genotypes, C4 (Smartiz violet fonce), C6 (Metis blank pur), C11 (Verano) and C13 (Metis origami) possessed higher positive or negative values compared with the other heat-sensitive genotypes with increased doses of GA3. These genotypes were shown to be less affected by heat stress, suggesting their positive response to hormone treatment. In conclusion, the above-mentioned genotypes, particularly heat-tolerant C15 and heat-sensitive C2 with the highest germination capacity and development can be selected as heat-resistant genotypes to be deposited in gene banks and used in further amelioration programs under biotic and/or abiotic stresses to develop resistant genotypes.

Creep properties and relevant deformation mechanisms of two low-cost nickel-based single crystal superalloys at elevated temperatures

In this work, the creep properties and relevant deformation mechanisms of the two self-designed low-cost single crystal superalloys were studied under the conditions of 1038 °C/172 MPa and 982 °C/248 MPa. The experimental alloys both displayed superior creep properties than the typical second-generation single crystal superalloy René N5. During high temperature creep tests, the rafted γ′ phase became more and more twisted with the decrease of distance away from the fracture surface, which was caused by the existence of a stress gradient in the gauge length section of the fractured specimen. Under high temperature and low stress conditions, the Re-free alloy displayed denser dislocation networks under both test conditions. Based on the nodal reaction theory, the dislocation networks with different shapes formed by reactions of a/2<110> dislocations at the γ/γ′ interface. Furthermore, the morphology of dislocation networks could transform from initial rectangles to octagons and then to thick hexagons. Under the condition of 982 °C/248 MPa, some parallel dislocation arrays in γ′ particles caused by dislocations pile-up was found in the Re-low alloy, and the main obstacles to the motion of dislocations were K–W locks and a<010> superdislocations. Based on the calculated critical resolved shear stresses, the primary deformation mechanism of the two experimental alloys under elevated temperature and low stress conditions was identified as dislocations slipping in γ matrix and climbing over rafted γ′ phase.

Impact of temperature and soil moisture on paddy weed and productivity: A case of Lalitpur District, Nepal

Rice (Oryza sativa L.) is a major food crop for around 60% of the global population. The production of rice has been challenged by various biotic and abiotic factors. Temperature and soil moisture are the major abiotic and weeds are the major biotic factors for yield loss. The present experiment was conducted to investigate the impact of temperature and soil moisture on rice weed and rice productivity. The experiment was carried out under different temperatures (ambient, ambient +2°C, and ambient +3°C) and soil moisture (ambient, 25-30%, and 10-15%) conditions for the entire crop growth period from June to October 2014. Rice weeds were recorded after 28, 47 and 93 days of rice transplantation for varied soil moisture. Similarly, at varied temperature weeds were recorded after 19, 44 and 66 days of rice transplantation. The results showed that weed density increases under elevated temperature at 2°C and 3°C than under an ambient condition (existing in the surrounding area). An experiment on soil moisture stress indicates a reduction in rice productivity as the density of weed increases with the deficiency of soil moisture. Further studies on temperature and soil moisture resisting rice variety are essential. This study suggests that research on the control of weed species, targeting those weeds benefited at elevated temperature and soil moisture stress conditions, is necessary.

On the prediction of creep behaviour of alloy 617 using Kachanov-Rabotnov model coupled with multi-objective genetic algorithm optimisation

The accurate prediction of elevated-temperature creep behaviour of alloys is important for preventing catastrophic failure of systems operating under prolonged elevated temperature-stress conditions. Here, we couple the Kachanov-Rabotnov (K-R) creep model with a multi-objective genetic algorithm (MOGA) to predict the creep behaviour of Alloy 617 at 800°C, 900°C, and 1000°C, under various stress conditions. It is shown that the MOGA-optimised K-R creep model can capture the overall elevated-temperature behaviour of the alloy at 800°C under a wide range of stress conditions. However, at 900°C and 1000°C, oxidation leads to the atypical accumulation of creep plasticity, which the K-R model cannot account for. Nevertheless, it is shown that the proposed methodology of optimising the K-R model with a MOGA can consistently provide accurate results within the limits of the K-R model.

Biochemical and Associated Agronomic Traits in Gossypium hirsutum L. under High Temperature Stress

Heat tolerance is a physiologically and genetically complex trait regulated by multiple genes. To investigate the genetic basis of heat tolerance, eight parents (five lines and three testers) and their fifteen F1 hybrids were evaluated under normal and high-temperature stress conditions for two consecutive years. Data were recorded for plant height, number of bolls, boll weight, seed cotton yield, ginning out turn (GOT%), H2O2, catalase, peroxidase, super-oxidase dismutase, total soluble proteins, carotenoids, chlorophyll a &amp; b contents, short fiber index, fiber strength, UHML, micronaire value, reflectance, and uniformity index. Line × tester analysis suggested that the contribution of lines was higher than testers. Non-additive gene action was observed for all studied traits. The variances of SCA were greater than GCA variances for all studied traits revealed that these traits were governed by a few largely dominant genes. Fb-Shaheen, Eagle-2 and JSQ White Gold were found good general combiner whereas the cross Fb-Shaheen × JSQ White Gold was a good specific combiner and revealed significant better parent heterosis for most of the traits during two years under normal and high temperature stress conditions. The information obtained could be utilized in a breeding program for the development of new synthetic varieties of heat tolerance.

Aqueous smoke and karrikin influence seed germination of Amaranthus dubius in varying light, temperature and osmotic stress conditions

Amaranthus dubius is a green leafy vegetable that contributes significantly to food and nutrition security in sub-Saharan Africa. We explored the influence of plant-derived aqueous smoke and karrikin on Amaranthus dubius seed germination under varying environmental conditions. Final germination percentage, germination index, mean germination time, coefficient of velocity of germination and germination rate index were measured in a completely randomized design consisting of smoke-water and karrikin treatments with four replications. Light conditions significantly influenced germination of Amaranthus dubius seeds, with constant dark and constant light conditions stimulating the greatest and least response, respectively. High temperatures favored the best seed germination response, irrespective of smoke-water or karrikin treatments. The optimum temperature for seed germination of 35 °C suggests high tolerance to heat stress conditions. Decrease in water potential significantly reduced germination irrespective of seed treatments with aqueous smoke and karrikin solutions. However, aqueous smoke seemed to have mitigated drought stress under moderate water potential (-0.15 MPa). The capacity of Amaranthus dubius seeds to germinate under high temperatures and seed treatment with aqueous smoke could extend its cultivation in heat-prone and moderately dry environments, thus broadening the food base in such environments.

Brassinosteroid-lipid membrane interaction under low and high temperature stress in model systems

BackgroundIn earlier studies [1], we indicated that applying brassinosteroids (BRs) to lipids that had been isolated from plants altered the physicochemical properties of the monolayers. A continuation of these dependencies using the defined model lipid systems is presented in this paper. The influence of homocastasterone (HCS) and castasterone (CS) (BRs for which the increase in concentration were characteristic of plants grown at low temperatures) on the membrane properties of their polar and the hydrophobic parts were studied.ResultsChanges in the electrokinetic potential indicate that both BRs decreased the negative charge of the surface, which is an important factor in modifying the contacts with the polar substances. This property of BRs has not yet been described. The studies of the interactions that occur in the hydrophobic part of the membrane were investigated using the EPR methods and Langmuir techniques. The physicochemical parameters of the lipid structure were determined, and the excess of Gibbs free energy was calculated.ConclusionWe conclude that examined BRs modify both the hydrophilic and hydrophobic properties of the membranes, but to a greater extent HCS. The consequence of these changes may be the attempt to maintain the stability of the membranes in stressful temperature conditions and / or to the possibility of adsorption of other substances on membranes surfaces. The change of plant metabolism towards increasing the amount of BR, mainly HCS (under cooling) may by an important factor for maintaining optimal structural properties of membranes and their functionality despite temperature changes.

Unprecedented early-summer heat stress and forecast of coral bleaching on the Great Barrier Reef, 2021-2022

The Great Barrier Reef (GBR) is predicted to undergo its sixth mass coral bleaching event during the Southern Hemisphere summer of 2021-2022. Coral bleaching-level heat stress over the GBR is forecast to start earlier than any previous year in the satellite record (1985-present). The National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch (CRW) near real-time satellite-based heat stress products were used to investigate early-summer sea surface temperature (SST) and heat stress conditionson the GBR during late 2021. As of 14 December 2021, values of instantaneous heat stress (Coral Bleaching HotSpots) and accumulated heat stress over a 12-week running window (Degree Heating Weeks) on the GBR were unprecedented in the satellite record. Further, 89% of GBR satellite reef pixels for this date in 2021 had a positive seven-day SST trend of greater than 0.2 degrees Celsius/week. Background temperatures (the minimum temperature over the previous 29 days) were alarmingly high, with 87% of GBR reef pixels on 14 December 2021 being greater than the maximum SST over that same 29-day period for any year from 1985-2020. The GBR is starting the 2021-2022 summer season with more accumulated heat than ever before, which could have disastrous consequences for the health, recovery, and future of this critical reef system.

Genome-Wide Identification, Characterization, and Expression Analysis of TUBBY Gene Family in Wheat (Triticum aestivum L.) under Biotic and Abiotic Stresses

The TUBBY gene family is a group of transcription factors found in animals and plants with many functions. TLP genes have a significant role in response to different abiotic stresses. However, there is limited knowledge regarding the TUBBY gene family in T. aestivum. Here we identified 40 TaTLP genes in wheat to reveal their potential function. This study found that TUBBY (TaTLP) genes are highly conserved in wheat. The GO analysis of TaTLP genes revealed their role in growth and stress responses. Promoter analysis revealed that most TaTLPs participate in hormone and abiotic stress responses. The heatmap analysis also showed that TaTLP genes showed expression under various hormonal and abiotic stress conditions. Several genes were upregulated under different hormonal and temperature stresses. The qRT-PCR analysis confirmed our hypotheses. The results clearly indicate that various TaTLP genes showed high expression under temperature stress conditions. Furthermore, the results showed that TaTLP genes are expressed in multiple tissues with different expression patterns. For the first time in wheat, we present a comprehensive TaTLP analysis. These findings provide valuable clues for future research about the role of TLPs in the abiotic stress process in plants. Overall, the research outcomes can serve as a model for improving wheat quality through genetic engineering.

Detection of seed vigour differences in Festuca sinensisseed lots

The selection of high vigour seeds significantly affects stand establishment and initial plant growth, particularly in harsh environments. Several tests, including standard germination (SG), seed vigour index (SVI), germination under water and temperature stress conditions, radicle emergence (RE) counts, accelerated ageing (AA) and electrical conductivity (EC), were applied to evaluate the vigour of 12 seed lots of Festuca sinensis. The SG showed that all seed lots attained high germination ranging from 86 to 96%; no significant correlation was observed between SG and seedling emergence (SE) in field experiments over two years (2020 and 2021). The RE count at 88 hours, germination (15°C and -0.2 MPa) were the most correlated with SE (r = 0.881 and 0.851, respectively, P &lt; 0.01), followed by AA (42°C for 48 hours) and SVI (0.836 and 0.753, respectively, P &lt; 0.01). Thus, RE counts at 88 hours, germination (15°C and -0.2 MPa), SVI and AA (42°C for 48 hours) accurately detect vigour difference of F. sinensis seed lots and provide similar data to those for SE in the field.

Transport Characteristics of Interfacial Charge in SiC Semiconductor-Epoxy Resin Packaging Materials.

The silicon carbide (SiC) wide bandgap (WBG) semiconductor power device has been widely applied for its excellent properties. However, the charge accumulated in the interface of SiC semiconductor-related insulation packaging may lead to serious material performance degradation and failure, threatening the reliability and operation life of power devices. In this research, interface charge accumulation characteristics of SiC–epoxy resin double-layered material were investigated, and space charge injection, transport, and accumulation mechanisms, as well as the related temperature effect for the SiC–epoxy resin under polarization and depolarization conditions, were studied by the pulsed electro-acoustic (PEA) technique. The results show that a charge peak appears between the SiC–epoxy resin interface, which shows the same polarity as the SiC side electrode. Charge injects from the SiC electrode, transports along with the SiC semiconductor bulk due to the high mobility, and is blocked by the interface barrier. In addition, under high temperature and high electrical stress conditions, obvious charge accumulation occurs inside the epoxy resin bulk, which was captured by the deep traps. The charge accumulation of the SiC-insulation packaging material can influence the operation of the power device and should attract more attention.

Comparative Analysis of Canopy Cooling in Wheat under High Temperature and Drought Stress

The size and the weight of wheat grains vary across the length of each spike (Triticum aestivum L.). High temperature and water scarcity often reduce the single grain weight, and this reduction also varies across the spike length. Plants tend to cope with high temperature and drought stress through inherent mechanisms such ascanopy cooling through transpiration, which can contribute to yield stability. The effect of canopy cooling on the average grain weight at different positions in spike is still unknown. In this study, we planned to assess the role of canopy temperature, yield-related traits, and spike shape in final grain weight. For two years (2017–2018 and 2018–2019), fifteen diverse genotypes released for cultivation in different environmental conditions were grown in the field. They were examined for canopy temperature, spikelets spike−1, grain number spike−1, grain yield spike−1, and grain weight of the spike’s basal, median, and distal regions. The Pearson correlation coefficient (r) was obtained for all pair-wise combinations of traits under different treatments and spike shapes. The results indicated that cooler canopy is correlated to grain weight in normal spike shape at all three positions within the spike irrespective of stress. The advantage of the cooler canopy in improving grain-filling at basal, median, and distal regions was more conspicuous in the high temperature stress conditions compared to non-stressed and drought conditions.

The combination of hypoxia and high temperature affects heat shock, anaerobic metabolism, and pentose phosphate pathway key components responses in the white shrimp (Litopenaeus vannamei).

Due to global warming, world water bodies have higher temperatures and lower oxygen concentrations that affect aquatic species including the white shrimp Litopenaeus vannamei. This species withstands these conditions, but the information of the physiological responses that allow them to survive are scarce. We analyzed the effects of high temperature, hypoxia, reoxygenation, and the combination of these factors on the relative expression of selected genes: HSF1, Hsp70, p53, TIGAR, HIF-1α, and VEGF1-3 in gills of L. vannamei. Additionally, glucose, lactate, NADP, and NADPH were determined. HSF1 was up-regulated in the high temperature and oxygen stress conditions, but Hsp70 was up-regulated only in reoxygenation at both temperatures. HIF-1α was also up-regulated by reoxygenation in both temperatures. Meanwhile, the VEGF genes were not altered by the stress conditions, since none of them changed expression drastically. p53 relative expression remained stable at the tested stress conditions, which prompts to the maintenance of antioxidant defenses. TIGAR expression was induced in normoxia and hypoxia at high temperature, which induced NADPH content helping to scavenge reactive oxygen species (ROS). Additionally, high temperature caused higher glucose and lactate content in normoxia and hypoxia, indicating carbohydrate mobilization and a switch to anaerobic metabolism. The results showed that HSF1, the anaerobic metabolism and the pentose phosphate pathway (PPP) are crucial for the shrimp response to these abiotic stress conditions and contribute to their survival.

Effect of temperature and stress on high temperature creep behavior of Ni3Al-based single crystal superalloy

The creep behavior and dislocations mechanism of the Ni3Al-based single crystal alloy IC6SX with [001] orientation were investigated under the testing conditions of 1100 ​°C/137 ​MPa, 1100 ​°C/120 ​MPa and 1070 ​°C/137 ​MPa. It was observed that the temperature and stress had a significant effect on the high temperature creep life of the single crystal alloy. As the temperature was reduced from 1100 ​°C to 1070 ​°C, the creep life increased from 65.07 ​h to 313.8 ​h. As the stress was reduced to 120 ​MPa, the creep life increased to 243.3 ​h. Under the high temperature and low stress condition the dislocations entered the γ′ phase by climbing caused by the atomic diffusion, instead of slipping.

Design and Analysis of Native Photorespiration Gene Motifs of Promoter Untranslated Region Combinations Under Short Term Abiotic Stress Conditions.

Quantitative traits are rarely controlled by a single gene, thereby making multi-gene transformation an indispensable component of modern synthetic biology approaches. However, the shortage of unique gene regulatory elements (GREs) for the robust simultaneous expression of multiple nuclear transgenes is a major bottleneck that impedes the engineering of complex pathways in plants. In this study, we compared the transcriptional efficacies of a comprehensive list of well-documented promoter and untranslated region (UTR) sequences side by side. The strength of GREs was examined by a dual-luciferase assay in conjunction with transient expression in tobacco. In addition, we created suites of new GREs with higher transcriptional efficacies by combining the best performing promoter-UTR sequences. We also tested the impact of elevated temperature and high irradiance on the effectiveness of these GREs. While constitutive promoters ensure robust expression of transgenes, they lack spatiotemporal regulations exhibited by native promoters. Here, we present a proof-of-principle study on the characterization of synthetic promoters based on cis-regulatory elements of three key photorespiratory genes. This conserved biochemical process normally increases under elevated temperature, low CO2, and high irradiance stress conditions and results in ∼25% loss in fixed CO2. To select stress-responsive cis-regulatory elements involved in photorespiration, we analyzed promoters of two chloroplast transporters (AtPLGG1 and AtBASS6) and a key plastidial enzyme, AtPGLP using PlantPAN3.0 and AthaMap. Our results suggest that these motifs play a critical role for PLGG1, BASS6, and PGLP in mediating response to elevated temperature and high-intensity light stress. These findings will not only enable the advancement of metabolic and genetic engineering of photorespiration but will also be instrumental in related synthetic biology approaches.

Effect of overload on creep deformation, crack initiation and growth behaviors of a C(T) specimen for 12Cr steel

12Cr steel is used as one of the materials for steam turbine rotor. Steam turbine rotor is an important component and high reliability is required. In actual turbine rotor which has central hole, thermal stress induced by inflow of steam is generated at start-up. At this time, an overload greater than the load level during steady-state operation is exerted on the stress concentration area near the central hole. Therefore, it is important to evaluate the effect of overload on the creep crack initiation and growth behavior.In this study, using a C(T) specimen for 12Cr steel used for steam turbine rotor, crack growth tests under creep and initial overload creep conditions were conducted and behaviors of creep deformation, crack initiation and growth were investigated. In addition, these results were evaluated by various fracture mechanics parameters. As a result, it was found that the initial overload suppressed creep deformation and delayed creep crack initiation. Especially, this tendency was more pronounced at the low temperature and high stress condition. However, the initial overload does not significantly affect the creep crack growth rate.

Unprecedented early-summer heat stress and forecast of coral bleaching on the Great Barrier Reef, 2021-2022

The Great Barrier Reef (GBR) is predicted to undergo its sixth mass coral bleaching event during the Southern Hemisphere summer of 2021-2022. Coral bleaching-level heat stress over the GBR is forecast to start earlier than any previous year in the satellite record (1985-present). The National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch (CRW) near real-time satellite-based heat stress products were used to investigate early-summer sea surface temperature (SST) and heat stress conditionson the GBR during late 2021. As of 14 December 2021, values of instantaneous heat stress (Coral Bleaching HotSpots) and accumulated heat stress over a 12-week running window (Degree Heating Weeks) on the GBR were unprecedented in the satellite record. Further, 89% of GBR satellite reef pixels for this date in 2021 had a positive seven-day SST trend of greater than 0.2 degrees Celsius/week. Background temperatures (the minimum temperature over the previous 29 days) were alarmingly high, with 87% of GBR reef pixels on 14 December 2021 being greater than the maximum SST over that same 29-day period for any year from 1985-2020. The GBR is starting the 2021-2022 summer season with more accumulated heat than ever before, which could have disastrous consequences for the health, recovery, and future of this critical reef system.

A multi-environment framework to evaluate the adaptation of wheat (Triticum aestivum) to heat stress

Key messageAssessing adaptation to abiotic stresses such as high temperature conditions across multiple environments presents opportunities for breeders to target selection for broad adaptation and specific adaptation.Adaptation of wheat to heat stress is an important component of adaptation in variable climates such as the cereal producing areas of Australia. However, in variable climates stress conditions may not be present in every season or are present to varying degrees, at different times during the season. Such conditions complicate plant breeders’ ability to select for adaptation to abiotic stress. This study presents a framework for the assessment of the genetic basis of adaptation to heat stress conditions with improved relevance to breeders’ selection objectives. The framework was applied here with the evaluation of 1225 doubled haploid lines from five populations across six environments (three environments selected for contrasting temperature stress conditions during anthesis and grain fill periods, over two consecutive seasons), using regionally best practice planting times to evaluate the role of heat stress conditions in genotype adaptation. Temperature co-variates were determined for each genotype, in each environment, for the anthesis and grain fill periods. Genome-wide QTL analysis identified performance QTL for stable effects across all environments, and QTL that illustrated responsiveness to heat stress conditions across the sampled environments. A total of 199 QTL were identified, including 60 performance QTL, and 139 responsiveness QTL. Of the identified QTL, 99 occurred independent of the 21 anthesis date QTL identified. Assessing adaptation to heat stress conditions as the combination of performance and responsiveness offers breeders opportunities to select for grain yield stability across a range of environments, as well as genotypes with higher relative yield in stress conditions.

Ageing Characterization Under Thermal Test of a Receiver Unit for a Radio Telescope

The Square Kilometer Array low (SKAlow) is an outstanding project aiming at building the world&#x2019;s largest and most sensitive radio telescope. The Australian Murchison Shire desert has been chosen as location for the low-frequency antennas because of many reasons, such as the atmospheric above the site and the radio quietness due to one of the most remote location worldwide. This location is the optimal choice by a radio astronomy and RF engineering point of views. However, it brings several drawbacks in terms of system availability due to the high temperature conditions that deeply affect the electronics reliability, and the difficulties and the costs associated to maintenance tasks performed in a remote location. Thus, it is fundamental to study the reliability and functional performances of the auxiliary electronic devices in the antennas array using adequate aging tests under temperature stress conditions. The experimental activities carried out in this work allowed to investigate the outbreak of failure mechanisms due to aging and hot temperature conditions in the receiver unit for low-frequency antennas of the SKA project. The experimental results are intended to better determine the strengths and weaknesses of the device under test in order to optimize its installation, its maintenance operations and its functionalities.

Physiological Characteristics of Cultivated Tepary Bean (Phaseolus acutifolius A. Gray) and Its Wild Relatives Grown at High Temperature and Acid Soil Stress Conditions in the Amazon Region of Colombia.

Common bean (Phaseolus vulgaris L.) is sensitive to different types of abiotic stresses (drought, high temperature, low soil fertility, and acid soil), and this may limit its adaptation and consequently to its yield under stress. Because of this, a sister species, tepary bean (Phaseolus acutifolius A. Gray), has recently gained attention in breeding for improved abiotic stress tolerance in common bean. In this study, we evaluated the adaptation of 302 accessions of tepary bean (Phaseolus acutifolius A. Gray) and its wild relatives (grouped in four types of tepary bean genetic resource: cultivated, acutifolius regressive, acutifolius wild, tenuifolius wild) when grown under high temperature and acid soil conditions with aluminum toxicity in the Amazon region of Colombia. Our objective was to determine differences among four types of tepary bean genetic resource in their morpho-phenological, agronomic, and physiological responses to combined high temperature and acid soil stress conditions. We found that cultivated P. acutifolius var acutifolius presented a greater number of pods per plant, as well as larger seeds and a greater number of seeds per pod. Some traits, such as root biomass, days to flowering and physiological maturity, specific leaf area, and stomatal density, showed significant differences between types of tepary bean genetic resource, probably contributing to difference in adaptation to combined stress conditions of high temperature and acid soil conditions. The photochemical quenching (qP) was higher in cultivated P. acutifolius var. acutifolius, while energy dissipation by non-photochemical quenching (NPQ) in the form of heat and the coefficient of non-photochemical dissipation (qN) were higher in acutifolius regressive and tenuifolius wild accessions. We have identified 6 accessions of cultivated and 19 accessions of tenuifolius wild that exhibited grain yields above 1800 kg ha−1. These accessions could be suitable to use as parents to improve dry seed production of tepary bean under combined stress conditions of high temperature and acid soil.