scholarly journals QTL Mapping and Identification of Candidate Genes for Heat Tolerance at the Flowering Stage in Rice

2020 ◽  
Author(s):  
Lei Chen ◽  
Qiang Wang ◽  
Xiaoli Zhang ◽  
Maoyan Tang ◽  
Yinghua Pan ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Bulked Segregant Analysis ◽  
Abiotic Stress Tolerance ◽  
Rice Variety ◽  
Complex Trait ◽  
High Temperature Stress ◽  
Chromosome 8 ◽  
Flowering Stage ◽  
Backcross Population ◽  
Heat Tolerant

Abstract Background: High-temperature stress can cause serious abiotic damage that limits the yield and quality of rice. Heat tolerance during the flowering stage of rice is a key trait that can guarantee a high and stable yield under heat stress. Heat tolerance is a complex trait that is regulated by numerous quantitative trait loci (QTLs); of which, however, few underlying genes have been fine mapped and cloned.Results: In this study, the F2:3 population derived from a cross between Huanghuazhan (HHZ), a heat-tolerant indica cultivar, and 9311, a heat-sensitive indica rice variety, were used to map the QTLs for heat tolerance during the flowering stage of rice. The F2:3 lines were treated under 38 °C from 9:30 am to 3:30 pm continuously for 3 days in a phytotron, and spikelet fertility was assessed. A new major QTL, qHTT8, controlling heat tolerance was located on chromosome 8 using the bulked-segregant analysis (BSA)-seq method. The QTL qHTT8 was determined to be located in the 355500–4520000 bp region, with a size of 0.965 Mb. The candidate region of qHTT8 on chromosome 8 contained 65 predicted genes. Ten putative predicted genes were found to be associated with abiotic stress tolerance. In future studies, the backcross population will be constructed to fine map and validate the effect of qHTT8.Conclusion: The information obtained in this study is useful for the fine mapping and cloning of qHTT8 and breeding heat-tolerant varieties of rice using marker-assisted selection.

scholarly journals QTL Mapping and Identification of Candidate Genes for Heat Tolerance at the Flowering Stage in Rice

2021 ◽  
Vol 11 ◽  
Author(s):  
Lei Chen ◽  
Qiang Wang ◽  
Maoyan Tang ◽  
Xiaoli Zhang ◽  
Yinghua Pan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Abiotic Stress ◽  
High Temperature ◽  
Candidate Genes ◽  
Heat Tolerance ◽  
Bulked Segregant Analysis ◽  
Abiotic Stress Tolerance ◽  
Chromosome 8 ◽  
Flowering Stage ◽  
Heat Tolerant

High-temperature stress can cause serious abiotic damage that limits the yield and quality of rice. Heat tolerance (HT) during the flowering stage of rice is a key trait that can guarantee a high and stable yield under heat stress. HT is a complex trait that is regulated by multiple quantitative trait loci (QTLs); however, few underlying genes have been fine mapped and cloned. In this study, the F2:3 population derived from a cross between Huanghuazhan (HHZ), a heat-tolerant cultivar, and 9311, a heat-sensitive variety, was used to map HT QTLs during the flowering stage in rice. A new major QTL, qHTT8, controlling HT was identified on chromosome 8 using the bulked-segregant analysis (BSA)-seq method. The QTL qHTT8 was mapped into the 3,555,000–4,520,000 bp, which had a size of 0.965 Mb. The candidate region of qHTT8 on chromosome 8 contained 65 predicted genes, and 10 putative predicted genes were found to be associated with abiotic stress tolerance. Furthermore, qRT-PCR was performed to analyze the differential expression of these 10 genes between HHZ and 9311 under high temperature conditions. LOC_Os08g07010 and LOC_Os08g07440 were highly induced in HHZ compared with 9311 under heat stress. Orthologous genes of LOC_Os08g07010 and LOC_Os08g07440 in plants played a role in abiotic stress, suggesting that they may be the candidate genes of qHTT8. Generally, the results of this study will prove useful for future efforts to clone qHTT8 and breed heat-tolerant varieties of rice using marker-assisted selection.

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.

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 SHORT DURATION HEAT PRECONDITIONING AND HEAT TOLERANCE IN ORNAMENTAL BEDDING PLANTS

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 874d-874
Author(s):  
Seenivasan Natarajan ◽  
Jeff S. Kuehny ◽  
James E. Board
Keyword(s):  
Heat Stress ◽  
Stomatal Conductance ◽  
Plant Growth ◽  
Short Duration ◽  
Heat Tolerance ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
High Temperature Stress ◽  
Bedding Plants ◽  
Heat Tolerant

One of the greatest impediments to production of marketable ornamental herbaceous plants in southern U.S. is high temperature stress. Exposure of plants to sub-lethal temperature (heat preconditioning) before sustained heat stress helps some plants to tolerate subsequent heat stress a phenomenon often referred as acquired thermotolerance. The objective of this research was to examine various morphological, physiological and anatomical responses of `Vista red' (heat tolerant) and `Sizzler red'(heat sensitive) cultivars of Salvia splendens to heat preconditioning (HC) and subsequent heat stress treatments (challenging temperatures, CT). Cultivars of Salvia were subjected to short duration HC of 35 °C for 3 hours every third day until 5 weeks after germination and subsequent exposure to two CT treatments 30/23 °C and 35/28 °C (D/N) cycles in growth chambers for the next five weeks. Plant growth, marketable quality, stomatal conductance and net photosynthesis declined for Sizzler Red without HC treatment. Compared with nonpreconditioned plants, heat preconditioned Sizzler Red had 38.28% higher root dry weight, 95% greater leaf thickness, 50% higher marketable quality at 35/28 °C heat stress condition. Heat preconditioning helped both Vista Red and Sizzler to survive in both the heat stress treatments. Vista Red had greater heat tolerant traits than Sizzler Red, these traits exacerbated with heat preconditioning treatment. The results demonstrated that heat preconditioning enhanced heat tolerance in cultivars of Salvia, which could be related to maintenance of dense plant growth with shorter internodes, thicker stems, greater stomatal conductance, extensive root growth that compensated the transpirational water loss and overall cooling of plants.

scholarly journals Impedance Flow Cytometry for Selection of Pollen Traits Under High Temperature Stress in Pepper

HortScience ◽  
2022 ◽  
Vol 57 (2) ◽  
pp. 181-190
Author(s):  
Shih-wei Lin ◽  
Tsung-han Lin ◽  
Cynthia Kung Man Yee ◽  
Joyce Chen ◽  
Yen-wei Wang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
High Temperature ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Pollen Viability ◽  
High Temperature Stress ◽  
Limiting Factor ◽  
Climate Change Scenarios ◽  
Heat Treated ◽  
Heat Tolerant

High temperature stress is a major limiting factor for pepper productivity, which will continue to be a problem under climate change scenarios. Developing heat tolerant cultivars is critical for sustained pepper production, especially in tropical and subtropical regions. In fruiting crops, like pepper, reproductive tissues, especially pollen, are the most sensitive to high temperature stress. Typically, pollen viability and germination are assessed through staining and microscopy, which is tedious and potentially inaccurate. To increase efficiency in assessing pollen traits of pepper, the use of impedance flow cytometry (IFC) has been proposed. We conducted three independent experiments to determine the most effective methodology to use IFC for evaluating pollen traits for heat tolerance in pepper. Seven floral developmental stages were evaluated, and stages 3, 4, and 5 were found to best combine high pollen concentration and activity. Flowers in development stages 3, 4, or 5 were then heat treated at 41, 44, 47, 50, and 55 °C or not heat treated (control). The critical temperature to assess heat tolerance using IFC was found to be 50 °C, with a reduction in pollen activity and concentration occurring at temperatures greater than 47 °C. Twenty-one entries of pepper were then accessed for pollen traits using the staining and IFC methods over 2 months, April (cooler) and June (hotter). Growing environment was found to be the greatest contributor to variability for nearly all pollen traits assessed, with performance during June nearly always being lower. PBC 507 and PBC 831 were identified as being new sources of heat tolerance, based on using IFC for assessing pollen. Pollen viability determined by staining and pollen activity determined using IFC were significantly positively correlated, indicating that IFC is an efficient and accurate method to assess pollen traits in pepper. This work provides a basis for further research in this area and supports more efficient breeding of heat-tolerant cultivars.

scholarly journals Indices and their Applicability under High Temperature in Potato (Solanum tuberosum L.) Cultivars

2015 ◽  
Vol 43 ◽  
pp. 63-68 ◽  
Author(s):  
Sreyashi Paul ◽  
Nirmali Gogoi
Keyword(s):  
High Temperature ◽  
Stress Tolerance ◽  
Heat Tolerance ◽  
Abiotic Stress Tolerance ◽  
Geometric Mean ◽  
High Temperature Stress ◽  
Potato Cultivars ◽  
Tolerance Index ◽  
Temperature Conditions ◽  
Heat Tolerance Index

The increasing temperature is going to be more vulnerable for cool season crops like potato which requires an optimum productivity temperature of 18 to 20 °C. Thus, breeding for heat tolerance has become very important. Therefore, some previously used indices for abiotic stress tolerance have been used in our study for screening of high temperature stress tolerance in potato. Three high yielding (Kufri jyoti, Kufri megha and Kufri pokraj) and two local (Rangpuria and Badami) commonly grown potato cultivars were selected for our experiment. Potato cultivars were sown under normal condition and two high temperature conditions (polyhouse and early season) and indices such as HSI (heat susceptibility index), HTI (heat tolerance index), GM (geometric mean) and HII (heat intensity index) were used to evaluate the performance of the cultivars under all the three temperature conditions. The positive and significant correlation between HTI (heat tolerance index), and GM (geometric mean) as well as with tuber yield under all the conditions revealed that these indices were efficient in selecting the high temperature tolerant potato cultivars. We recorded the equal applicability of these two indices for both high yielding and local group of potato cultivars. Our study revealed that cultivar Kufri megha and Rangpuria showed higher heat tolerance between high yielding and local cultivars respectively.

scholarly journals Nanopore-Based Comparative Transcriptome Analysis Reveals the Potential Mechanism of High-Temperature Tolerance in Cotton (Gossypium hirsutum L.)

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2517
Author(s):  
Yajun Liang ◽  
Zhaolong Gong ◽  
Junduo Wang ◽  
Juyun Zheng ◽  
Yizan Ma ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Shock ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Transcriptome Analysis ◽  
Target Genes ◽  
High Temperature Stress ◽  
Ethylene Signaling ◽  
Signaling Transduction ◽  
Heat Tolerant

Extreme high temperatures are threatening cotton production around the world due to the intensification of global warming. To cope with high-temperature stress, heat-tolerant cotton cultivars have been bred, but the heat-tolerant mechanism remains unclear. This study selected heat-tolerant (‘Xinluzao36′) and heat-sensitive (‘Che61-72′) cultivars of cotton treated with high-temperature stress as plant materials and performed comparative nanopore sequencing transcriptome analysis to reveal the potential heat-tolerant mechanism of cotton. Results showed that 120,605 nonredundant sequences were generated from the raw reads, and 78,601 genes were annotated. Differentially expressed gene (DEG) analysis showed that a total of 19,600 DEGs were screened; the DEGs involved in the ribosome, heat shock proteins, auxin and ethylene signaling transduction, and photosynthesis pathways may be attributed to the heat tolerance of the heat-tolerant cotton cultivar. This study also predicted a total of 5118 long non-coding RNAs (lncRNAs)and 24,462 corresponding target genes. Analysis of the target genes revealed that the expression of some ribosomal, heat shock, auxin and ethylene signaling transduction-related and photosynthetic proteins may be regulated by lncRNAs and further participate in the heat tolerance of cotton. This study deepens our understandings of the heat tolerance of cotton.

scholarly journals Mapping of QTL Associated With Heat Tolerance At The Reproductive Stage In Rice(Oryza Sativa L.)

2021 ◽  
Author(s):  
Liu Jin ◽  
Xiaoding Ma ◽  
Huiying Zhou ◽  
Shuhui Li ◽  
Di Cui ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Tolerance ◽  
Oryza Sativa L ◽  
Recombinant Inbred Lines ◽  
High Temperature Stress ◽  
Epistatic Effect ◽  
Major Qtls ◽  
Temperature Conditions ◽  
Significant Difference ◽  
Heat Tolerant

Abstract Climate change has a negative effect on rice production and food security. High temperature stress is a major obstacle and can significantly reduce yield. A set of recombinant inbred lines (RILs) derived from the cross between Longdao5 (heat-sensitive) and Zhongyouzao8 (heat-tolerant) was used in the identification of heat tolerant QTL. Spikelet fertility (SF) and heat tolerance (HT) indexes showed a significant difference among the parents and RILs population, and SF and HT have different of effect under natural and artificial high temperature conditions. Sixty-one QTLs were detected on chromosomes 1-8, 10 and 12, while 25, 27 and 14 additive QTLs were identified under the control, natural and artificial high temperature conditions, respectively. Pleiotropic effects and QTL hotspots are the key factors affecting these traits, three key major QTL clusters qHTSF1, qHTSF4, and qHTSF12 can be stably expressed. In addition, epistatic effect is an important component in the regulation of heat tolerance. A total of 17 pairs of epistatic interaction loci were detected, and these additive QTL clusters have a significant epistatic effect. Bulk segregant analysis (BSA) method was proved to be a convenient method to detect major QTLs. Three QTLs, namely qSF1, qSF2 and qSF12 were detected under high temperature environment, and there is a highly significant correlation among these addictive QTLs. These results will lay the foundation for the further fine mapping of these major QTLs and enrich the molecular marker-assisted selection of heat-tolerant gene resources in rice breeding.

Physiological and molecular characterisation for high temperature stress in Lens culinaris

2018 ◽  
Vol 45 (4) ◽  
pp. 474 ◽  
Author(s):  
Jitendra Kumar ◽  
Partha Sarathi Basu ◽  
Sunanda Gupta ◽  
Sonali Dubey ◽  
Debjyoti Sen Gupta ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Lens Culinaris ◽  
Electron Transport Rate ◽  
Pollen Viability ◽  
Photosynthetic Electron Transport ◽  
High Temperature Stress ◽  
Molecular Characterisation ◽  
Heat Stress Tolerance ◽  
Heat Tolerant ◽  
Tolerant Genotype

In the present study, 11 lentil (Lens culinaris Medik) genotypes including heat tolerant and heat sensitive genotypes identified after a screening of 334 accessions of lentil for traits imparting heat tolerance, were characterised based on physiological traits and molecular markers. Results showed a higher reduction in pollen viability among sensitive genotypes (up to 52.3%) compared with tolerant genotypes (up to 32.4%) at 43°C. Higher photosynthetic electron transport rate was observed among heat tolerant genotypes and two heat tolerant lentil genotypes, IG 4258 (0.43) and IG 3330 (0.38) were having highest Fv/Fm values. However, membrane stability was significantly higher in only one heat tolerant genotype, ILL 10712, indicating that different mechanisms are involved to control heat tolerance in lentil. The molecular characterisation of lentil genotypes with 70 polymorphic SSR and genic markers resulted into distinct clusters in accordance with their heat stress tolerance. A functional marker ISM11257 (intron spanning marker) amplifying an allele of 205 bp in size was present only among heat tolerant genotypes, and could be further used in a breeding program to identify heat tolerant lentil genotypes. The findings of this study will contribute to the development of heat tolerant lentil cultivars.

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