scholarly journals Unraveling Heat Tolerance in Upland Cotton (Gossypium hirsutum L.) Using Univariate and Multivariate Analysis

2022 ◽  
Vol 12 ◽  
Author(s):  
Muhammad Mubashar Zafar ◽  
Xue Jia ◽  
Amir Shakeel ◽  
Zareen Sarfraz ◽  
Abdul Manan ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Fiber Quality ◽  
High Temperature Stress ◽  
Stress Conditions ◽  
Cotton Yield ◽  
Mean Values ◽  
White Gold

The ever-changing global environment currently includes an increasing ambient temperature that can be a devastating stress for organisms. Plants, being sessile, are adversely affected by heat stress in their physiology, development, growth, and ultimately yield. Since little is known about the response of biochemical traits to high-temperature ambiance, we evaluated eight parental lines (five lines and three testers) and their 15 F1 hybrids under normal and high-temperature stress to assess the impact of these conditions over 2 consecutive years. The research was performed under a triplicate randomized complete block design including a split-plot arrangement. Data were recorded for agronomic, biochemical, and fiber quality traits. Mean values of agronomic traits were significantly reduced under heat stress conditions, while hydrogen peroxide, peroxidase, total soluble protein, superoxide dismutase, catalase (CAT), carotenoids, and fiber strength displayed higher mean values under heat stress conditions. Under both conditions, high genetic advance and high heritability were observed for seed cotton yield (SCY), CAT, micronaire value, plant height, and chlorophyll-a and b content, indicating that an additive type of gene action controls these traits under both the conditions. For more insights into variation, Pearson correlation analysis and principal component analysis (PCA) were performed. Significant positive associations were observed among agronomic, biochemical, and fiber quality-related traits. The multivariate analyses involving hierarchical clustering and PCA classified the 23 experimental genotypes into four groups under normal and high-temperature stress conditions. Under both conditions, the F1 hybrid genotype FB-SHAHEEN × JSQ WHITE GOLD followed by Ghuari-1, CCRI-24, Eagle-2 × FB-Falcon, Ghuari-1 × JSQ White Gold, and Eagle-2 exhibited better performance in response to high-temperature stress regarding the agronomic and fiber quality-related traits. The mentioned genotypes could be utilized in future cotton breeding programs to enhance heat tolerance and improve cotton yield and productivity through resistance to environmental stressors.

Agronomic, physiological and molecular characterisation of rice mutants revealed the key role of reactive oxygen species and catalase in high-temperature stress tolerance

2020 ◽  
Vol 47 (5) ◽  
pp. 440 ◽  
Author(s):  
Syed Adeel Zafar ◽  
Amjad Hameed ◽  
Muhammad Ashraf ◽  
Abdus Salam Khan ◽  
Zia-ul- Qamar ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Heat Stress ◽  
High Temperature ◽  
Grain Yield ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
High Temperature Stress ◽  
Oxygen Species ◽  
Selection Indices ◽  
Heat Tolerant

Climatic variations have increased the occurrence of heat stress during critical growth stages, which negatively affects grain yield in rice. Plants adapt to harsh environments, and particularly high-temperature stress, by regulating their physiological and biochemical processes, which are key tolerance mechanisms. The identification of heat-tolerant rice genotypes and reliable selection indices are crucial for rice improvement programs. Here, we evaluated the response of a rice mutant population for high-temperature stress at the seedling and reproductive stages based on agronomic, physiological and molecular indices. Estimates of variance components revealed significant differences (P < 0.001) among genotypes, treatments and their interactions for almost all traits. The principal component analysis showed significant diversity among genotypes and traits under high-temperature stress. The mutant HTT-121 was identified as the most heat-tolerant mutant with higher grain yield, panicle fertility, cell membrane thermo-stability (CMTS) and antioxidant enzyme levels under heat stress. Various seedling-based morpho-physiological traits (leaf fresh weight, relative water contents, malondialdehyde, CMTS) and biochemical traits (superoxide dismutase, catalase and hydrogen peroxide) explained variations in grain yield that could be used as selection indices for heat tolerance in rice during early growth. Notably, heat-sensitive mutants accumulated reactive oxygen species, reduced catalase activity and upregulated OsSRFP1 expression under heat stress, suggesting their key roles in regulating heat tolerance in rice. The heat-tolerant mutants identified in this study could be used in breeding programs and to develop mapping populations to unravel the underlying genetic architecture for heat-stress adaptability.

scholarly journals Protective Effects of Salicylic Acid and Calcium Chloride on Sage Plants (Salvia officinalis L. and Salvia elegans Vahl) under High-Temperature Stress

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2110
Author(s):  
Kuan-Hung Lin ◽  
Tse-Yen Lin ◽  
Chun-Wei Wu ◽  
Yu-Sen Chang
Keyword(s):  
Salicylic Acid ◽  
Heat Stress ◽  
High Temperature ◽  
Calcium Chloride ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Combined Treatment ◽  
High Temperature Stress ◽  
Fresh Market ◽  
Time Intervals

High-temperature stress is a major risk to fresh-market Salvia production, and heat intolerance is a major constraint in sage cultivation, particularly during the hot summer season. Previously, we investigated heat tolerance in five common-market cultivars of sage plants using leaf relative injury (RI) values and found that S. elegans Vahl (SE) and S. officinalis L. (SO) were the most and least heat-tolerant species, respectively. The exogenous applications of salicylic acid (SA) and calcium chloride (CaCl2) to alleviate heat stress in various species have been extensively studied, but reports of the effects of SA and CaCl2 treatments on the heat tolerance of sage plants are scarce. The objective of this study was to investigate how SA and CaCl2 affect the physiology and morphology of SE and SO plants under high-temperature conditions. Potted plants were pretreated with SA (0, 100, 200, 400, and 800 μM) and CaCl2 (0, 5, 10, and 15 mM), alone and combined, exposed to 55 °C and 80% humidity for 30 min, then placed in an environment-controlled chamber at 30°C for three days and evaluated for changes in phenotypic appearance, RI, spectral reflectance, and chlorophyll fluorescence indices at different time intervals. Plants watered without chemical solutions were used as controls. Our results show that the growth of SO plants pretreated with SA and CaCl2 was more robust, compared with control plants, which were considerably affected by heat stress, resulting in brown, withered leaves and defoliation. The effects of the combined applications of SA (100 μM) and CaCl2 (5 mM) to SO plants were superior to control plants in increasing values of soil-plant analysis development (SPAD), normalized difference vegetation index (NDVI), and the maximal quantum yield of photosystemII photochemistry (Fv/Fm), while reducing RI%. Furthermore, SO plants exhibited higher SPAD and Fv/Fm values and lower RI% than SE plants in combined treatments at all time intervals after heat stress, implying that different genotypes displayed variations in their SPAD, Fv/Fm, and RI%. Thus, a combined treatment of 100 μM of SA and 5 mM of CaCl2 is effective and beneficial to plant appearance and ability to ameliorate heat stress. These indices can be used as indicators to characterize the physiology of these plants and applied on a commercial scale for informing the development of rapid and precise management practices on bedded sage plants grown in plant factories to achieve maximum market benefit.

From qualitative to quantitative: a new approach for determining heat tolerance in cotton using triphenyl tetrazolium chloride

2020 ◽  
Author(s):  
Susan Yvonne Jaconis ◽  
Warren C Conaty ◽  
Alan J. E. Thompson ◽  
Shanna L Smith ◽  
Chiara Trimarchi ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
High Temperature Stress ◽  
Triphenyl Tetrazolium Chloride ◽  
Improvement Program ◽  
Breeding Programs ◽  
Tetrazolium Chloride ◽  
Viability Testing

Abstract Background Susceptibility of cotton to heat stress in cotton production systems is a major concern for breeding programs. It is hypothesised that in order to maintain or improve cotton yields and quality in sub-optimal future climates, the negative effects of high temperature stress must be mitigated. To address this need, a fast and effect way of quantifying thermotolerant phenotypes is required. Triphenyl tetrazolium chloride (TTC) based enzyme viability testing following high temperature stress can be used as a heat tolerance phenotype. This is because when live cells encounter a TTC solution, TTC undergoes a chemical reduction producing a visible, insoluble red product called triphenyl formazan, that can be quantified spectrophotometrically. However, existing TTC based cell viability assays cannot easily be deployed at the scale required in a crop improvement program. Results In this study, a heat stress assay (HSA) based on the use of TTC enzyme viability testing has been refined and improved for efficiency, reliability, and ease of use through four experiments. Sampling factors which may influence assay results such as leaf age, plant water status, and short-term cold storage were also investigated. Experiments conducted in this study have successfully down scaled the assay and identified an optimal sampling regime, enabling measurement of large segregating populations for application in breeding programs. The optimal durations of leaf disc exposure to TTC and the subsequent extraction of the formazan product in ethanol were identified as 16 h and 13 h, respectively; leading to enhanced clarity of assay results. Conclusions These improvements in the methodology provide a new level of confidence in results, ensuring applicability of the assay to a breeding program. The improved HSA methodology is important as it is proposed that long-term improvements in cotton thermotolerance can be achieved through concurrent selection of superior phenotypes based on the HSA and yield performance in hot environments. Additionally, a new way of interpreting both heat tolerance and heat resistance were developed to differentiate genotypes that perform well at the time of a heat stress event and those that maintain a similar level of performance to a non-stressed control.

scholarly journals A novel tolerance index to identify heat tolerance in cultivated and wild barley genotypes

2020 ◽  
Author(s):  
Forouzan Bahrami ◽  
Ahmad Arzani ◽  
Mehdi Rahimmalek
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Yield ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Agronomic Traits ◽  
High Temperature Stress ◽  
Tolerance Index ◽  
Barley Genotypes ◽  
Heat Tolerance Index

AbstractThermal stress at the reproductive stage poses a substantial constraint on cereal production worldwide. A two-year field study was conducted to assess tolerance to terminal heat stress in cultivated (Hordeum vulgare ssp. vulgare L.) and wild (H. vulgare ssp. spontaneum L.) barley genotypes using phenological and agronomic traits as well as selection indices based on grain yield. A new heat-tolerance index was tested while a simultaneous study was also carried out of both phenological and grain yield-related variables as well as previously defined indices. Results of analysis of variance showed the significant genotypic and high-temperature stress (environment) effects on all the traits studied. In contrast to the cultivated genotypes, the wild ones were found less affected by high-temperature stress. Moreover, both cultivated and wild genotypes were observed to use the life cycle shortening as a mechanism to evade heat stress. In addition, supplementary tolerance mechanisms were also found likely to contribute to heat-stress evasion in the wild germplasm. Grain yield showed a strong relationship with both stress tolerance index (STI) and heat tolerance index (HTI) among the wild genotypes. However, multivariate analysis highlighted the feasibility of HTI to screen high-temperature tolerant wild genotypes under harsh environments with the most high-temperature tolerant wild genotypes identified originating from warm climates.

High Temperature Stress in Wild Wheats and Spring Wheats

1994 ◽  
Vol 21 (6) ◽  
pp. 705 ◽  
Author(s):  
JG Waines
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Developmental Stages ◽  
Diploid Species ◽  
Geographic Area ◽  
High Temperature Stress ◽  
Wild Wheats ◽  
Wild Accessions

The effect of high temperature stress on wild and spring wheats is reviewed. Wild wheats include species in the genera Aegilops L. and Triticum L. Species exist in a polyploid series, diploid, tetraploid and hexaploid, based on the genome formula, n = x = 7 chromosomes. Commercial durum wheat is tetraploid with the genome formula BBAA, while bread wheat is hexaploid (BBAADD). Wheats grown at Riverside, California, from June to October exhibit heat stress at the vegetative and reproductive stages. Under high temperatures (28/15�C day/night) during the vegetative stage, many diploid species do not grow well. Wild diploid T. urartu (AA) and T. monococcum ssp. boeoticum (AA) exhibited more effects of heat stress than the goat grasses A. speltoides (SS = BB?) or A. tauschii (DD). Wild tetraploid T. turgidum L. ssp. dicoccoides Korn (BBAA) exhibited more vegetative-phase stress tolerance than the diploid wheats. Modern Mexican cultivars of durum and bread wheats showed good establishment under high field temperatures, but often tiller number was reduced, and the developmental stages were reduced in time. All the spring durum and bread wheats tested flowered and set seed. They produced anthers with fertile pollen, and they had reproductive heat tolerance. Many wild Aegilops and Triticum accessions did not boot for lack of vernalisation, or they showed reproductive heat stress. Ten wild accessions, including A. speltoides, A. longissima and A. searsii, showed normal vegetative and reproductive development and were considered heat tolerant. They came from the same geographic area in Palestine which should be searched for landraces of wheats that show heat tolerance.

scholarly journals Agronomic, physiological and molecular characterization of rice mutants revealed key role of ROS and catalase in high temperature stress tolerance

2019 ◽  
Author(s):  
Syed Adeel Zafar ◽  
Amjad Hameed ◽  
Muhammad Ashraf ◽  
Abdus Salam Khan ◽  
Zia-ul-Qamar ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
High Temperature Stress ◽  
Early Growth ◽  
Growth Stages ◽  
Breeding Programs ◽  
Selection Indices ◽  
Heat Tolerant

AbstractPlants adapt to harsh environments particularly high temperature stress by regulating their physiological and biochemical processes, which are key tolerance mechanisms. Thus, identification of heat-tolerant rice genotypes and reliable selection indices are crucial for rice improvement programs. Here, we evaluated the response of a rice mutant population for high-temperature stress at the seedling and reproductive stages based on agronomic, physiological and molecular traits. The estimate of variance components revealed significant differences (P<0.001) among genotypes, treatments and their interaction for almost all traits. Principal component analysis showed significant diversity among the genotypes and traits under high-temperature stress. The mutant ‘HTT-121’ was identified as the most heat tolerant mutant with higher grain yield, panicle fertility, cell membrane thermo-stability (CMTS) and antioxidant enzyme levels under heat stress conditions. Various seedling-based morpho-physiological traits (leaf fresh weight, relative water contents, malondialdehyde, CMTS) and biochemical traits (superoxide dismutase, catalase and hydrogen peroxide) explained variations in grain yield that could be used as selection indices for heat tolerance in rice at early growth stages. Notably, heat sensitive mutants showed a significant accumulation of ROS level, reduced activities of catalase and upregulation of OsSRFP1 expression under heat stress, suggesting their key role in regulating heat tolerance in rice. The heat-tolerant mutants identified in this study could be used in breeding programs and the development of mapping populations to unravel the underlying genetic architecture for heat-stress adaptability.Summary text for table of contentsHeat stress probably due to changing climate scenario has become a serious threat for global rice production. On the other side, efforts to develop high yielding cultivars have led to the reduced genetic variability to withstand harsh environmental conditions. This study aimed to identify novel heat tolerant mutants developed through gamma irradiation which will provide a unique genetic resource for breeding programs. Further, we have identified reliable selection indices for screening heat-tolerant rice germplasm at early growth stages.

scholarly journals Wheat (Triticum aestivum L.) TaHMW1D Transcript Variants Are Highly Expressed in Response to Heat Stress and in Grains Located in Distal Part of the Spike

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 687
Author(s):  
Chan Seop Ko ◽  
Jin-Baek Kim ◽  
Min Jeong Hong ◽  
Yong Weon Seo
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Two Dimensional Gel Electrophoresis ◽  
Transcript Variants

High-temperature stress during the grain filling stage has a deleterious effect on grain yield and end-use quality. Plants undergo various transcriptional events of protein complexity as defensive responses to various stressors. The “Keumgang” wheat cultivar was subjected to high-temperature stress for 6 and 10 days beginning 9 days after anthesis, then two-dimensional gel electrophoresis (2DE) and peptide analyses were performed. Spots showing decreased contents in stressed plants were shown to have strong similarities with a high-molecular glutenin gene, TraesCS1D02G317301 (TaHMW1D). QRT-PCR results confirmed that TaHMW1D was expressed in its full form and in the form of four different transcript variants. These events always occurred between repetitive regions at specific deletion sites (5′-CAA (Glutamine) GG/TG (Glycine) or (Valine)-3′, 5′-GGG (Glycine) CAA (Glutamine) -3′) in an exonic region. Heat stress led to a significant increase in the expression of the transcript variants. This was most evident in the distal parts of the spike. Considering the importance of high-molecular weight glutenin subunits of seed storage proteins, stressed plants might choose shorter polypeptides while retaining glutenin function, thus maintaining the expression of glutenin motifs and conserved sites.

Emergence of seedlings from different depths following high temperature stress

1975 ◽  
Vol 84 (3) ◽  
pp. 525-528 ◽  
Author(s):  
I. C. Onwueme ◽  
S. A. Adegoroye
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Seedling Emergence ◽  
High Temperature Stress ◽  
Moist Soil ◽  
Different Depths

SUMMARYSeeds of Amaranthus, melon, cowpea and tomato were planted in moist soil at 1, 4 or 7·5 cm depth and subjected to a heat stress of 45 °C for 10 h on the day of sowing (day 0), 1 day after sowing or 2 days after sowing. Seedling emergence was retarded by heat stress, the most drastic retardation being due to heat stress on day 1 for cowpea and tomato, day 2 for melon, and day 0 for Amaranthus. Emergence also decreased with increasing depth of sowing. The interaction of depth and heat stress was also significant in all cases, such that the delay in emergence due to heat stress tended to be greater with increasing depth of sowing. The agronomic significance of the results is discussed.

scholarly journals Assessment of Heat-tolerance Potential in QTL Introgressed Lines of Hybrid Rice Restorer, KMR-3R through PS-II Efficiency

2021 ◽  
pp. 258-266
Author(s):  
V. Jaldhani ◽  
D. Sanjeeva Rao ◽  
P. Beulah ◽  
B. Srikanth ◽  
P. R. Rao ◽  
...  
Keyword(s):  
High Temperature ◽  
Quantum Yield ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Photosynthetic Apparatus ◽  
High Temperature Stress ◽  
Maximum Efficiency ◽  
Photochemical Quenching ◽  
Psii Photochemistry ◽  
Heat Tolerant

Aims: To assess heat-induced PSII damage and efficiency in eight promising backcross introgression lines (BC2F6) of KMR-3R/N22 possessing qHTSF1.1 and qHTSF4.1. Study Design:  Randomized Complete Block Design (RCBD) with three replications. Place and Duration of Study: ICAR-Indian Institute of Rice Research, Hyderabad India during wet/rainy (Kharif) season 2018. Methodology: Eight ILs (BC2F6) and parents were evaluated for heat tolerance. The high- temperature stress was imposed by enclosing the crop with a poly cover tent (Polyhouse) just before the anthesis stage. The fluorescence parameters viz., maximum efficiency of PSII photochemistry (Fv/Fm), Electron transport rate (ETR), effective PSII quantum yield (ΦPSII), coefficient of photochemical quenching (qP) and coefficient of non-photochemical quenching (qN) were measured under ambient and high-temperature stress. Results: The heat-tolerance potential of ILs was assessed in terms of PSII activity. The results indicated that significant differences were observed between treatments (T), genotypes (G) and the interaction between T × G.  The physiological basis of introgressed QTLs controls the spikelet fertility by maintaining the productive and adaptive strategies in heat-tolerant QTL introgressed lines with stable photosynthetic apparatus (PSII) under high-temperature stress. Conclusion: The Fv/Fm ratio denotes the maximum quantum yield of PSII. The heat-tolerant QTL introgressed lines exhibited stable photosynthetic apparatus (PSII) and noted better performance under high-temperature stress. They may be used as donors for fluorescence traits in breeding rice for high-temperature tolerance.

scholarly journals Cell Membrane Stability as a Measure of Heat Tolerance in Hexaploid and Tetraploid Wheat

2020 ◽  
pp. 16-22
Author(s):  
Syed Bilal Hussain ◽  
Ali Bakhsh ◽  
Muhammad Zubair
Keyword(s):  
High Temperature ◽  
Cell Membrane ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Tetraploid Wheat ◽  
High Temperature Stress ◽  
Cell Membrane Stability ◽  
Leaf Stage ◽  
Heat Tolerant ◽  
Morphological Differences

A comparison was made of the physiological and morphological differences between Inqlab-91 (hexaploid) and Langdon (tetralpoid) wheat genotypes in response to high temperature stress applied at third leaf stage of growth. Electrolytes leakage technique was used to detect differences in the heat sensitivities of leaves of Inqlab-91 and Langdon. This method showed that at both 35 or 40°C Inqlab-91 was more heat tolerant than Langdon.

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