scholarly journals Accelerating Breeding for Heat Tolerance in Tomato (Solanum lycopersicum L.): An Integrated Approach

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 720 ◽  
Author(s):  
Mathieu Anatole Tele Ayenan ◽  
Agyemang Danquah ◽  
Peter Hanson ◽  
Charles Ampomah-Dwamena ◽  
Fréjus Ariel Kpêdétin Sodedji ◽  
...  
Keyword(s):  
Heat Stress ◽  
Confidence Interval ◽  
Heat Tolerance ◽  
Pollen Viability ◽  
Total Yield ◽  
Integrated Approach ◽  
Crop Productivity ◽  
Limiting Factor ◽  
Substitution Lines ◽  
Advanced Backcross

Heat stress is a major limiting factor for crop productivity. Tomato is highly sensitive to heat stress, which can result in a total yield loss. To adapt to current and future heat stress, there is a dire need to develop heat tolerant cultivars. Here, we review recent attempts to improve screening for heat tolerance and to exploit genetic and genomic resources in tomatoes. We provide key factors related to phenotyping environments and traits (morphological, physiological, and metabolic) to be considered to identify and breed thermo-tolerant genotypes. There is significant variability in tomato germplasm that can be harnessed to breed for thermo-tolerance. Based on our review, we propose that the use of advanced backcross populations and chromosome segments substitution lines is the best means to exploit variability for heat tolerance in non-cultivated tomato species. We applied a meta quantitative trait loci (MQTL) analysis on data from four mapping experiments to co-localize QTL associated with heat tolerance traits (e.g., pollen viability, number of pollen, number of flowers, style protrusion, style length). The analysis revealed 13 MQTL of which 11 were composed of a cluster of QTL. Overall, there was a reduction of about 1.5-fold in the confidence interval (CI) of the MQTL (31.82 cM) compared to the average CI of individual QTL (47.4 cM). This confidence interval is still large and additional mapping resolution approaches such as association mapping and multi-parent linkage mapping are needed. Further investigations are required to decipher the genetic architecture of heat tolerance surrogate traits in tomatoes. Genomic selection and new breeding techniques including genome editing and speed breeding hold promise to fast-track development of improved heat tolerance and other farmer- and consumer-preferred traits in tomatoes.

Phenotyping from lab to field – tomato lines screened for heat stress using Fv/Fm maintain high fruit yield during thermal stress in the field

2019 ◽  
Vol 46 (1) ◽  
pp. 44 ◽  
Author(s):  
Damodar Poudyal ◽  
Eva Rosenqvist ◽  
Carl-Otto Ottosen
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Pollen Viability ◽  
Crop Improvement ◽  
Field Performance ◽  
Net Photosynthesis ◽  
Plant Size ◽  
Fruit Yield ◽  
Heat Sensitivity ◽  
Solanum Lycopersicum L

This study aimed to phenotype young tomato (Solanum lycopersicum L.) plants for heat tolerance by measuring Fv/Fm after short-term heat treatments in climate chambers and selected sensitive (low Fv/Fm) and tolerant (high Fv/Fm) cultivars to investigate their in-field performance. Twenty-eight genotypes were phenotyped at 40:28°C for 2 days in climate chambers. A second screening (four high Fv/Fm and four low Fv/Fm genotypes) was conducted for 4 days at 38:28°C, followed by 5 days’ recovery (26:20°C). The tolerant genotypes maintained high net photosynthesis (PN) and increased stomatal conductance (gs) at 38°C, allowing better leaf cooling. Sensitive genotypes had lower Fv/Fm and PN at 38°C, and gs increased less than in the tolerant group, reducing leaf cooling. Under controlled conditions, all eight genotypes had the same plant size and pollen viability, but after heat stress, plant size and pollen viability reduced dramatically in the sensitive group. Two tolerant and two sensitive genotypes were grown in the field during a heat wave (38:26°C). Tolerant genotypes accumulated more biomass, had a lower heat injury index and higher fruit yield. To our knowledge, this is the first time screening for heat tolerance by Fv/Fm in climate chambers was verified by a field trial under natural heat stress. The differences after heat stress in controlled environments were comparable to those in yield between tolerant and sensitive groups under heat stress in the field. The results suggest that Fv/Fm is effective for early detection of heat tolerance, and screening seedlings for heat sensitivity can speed crop improvement.

scholarly journals Contrasting processing tomato cultivars unlink yield and pollen viability under heat stress

2021 ◽  
Author(s):  
Golan Miller ◽  
Avital Beery ◽  
Prashant Kumar Singh ◽  
Fengde Wang ◽  
Rotem Zelingher ◽  
...  
Keyword(s):  
Heat Stress ◽  
Crop Production ◽  
Fruit Set ◽  
Pollen Viability ◽  
Crop Productivity ◽  
Fruit Weight ◽  
General Acceptance ◽  
Processing Tomato ◽  
Tomato Processing ◽  
Tomato Cultivars

The occurring climate change is causing temperature increment in crop production areas worldwide, generating conditions of heat stress that negatively affect crop productivity. Tomato (Solanum lycopersicum), a major vegetable crop, is highly susceptible to conditions of heat stress. When tomato plants are exposed to ambient day/night temperatures that exceed 32°C/20°C respectively during the reproductive phase, fruit set and fruit weight are reduced, leading to a significant decrease in yield. Processing tomato cultivars are cultivated in open fields, where environmental conditions are not controlled, therefore plants are exposed to multiple abiotic stresses, including heat stress. Understanding the physiological response of modern processing tomato cultivars to heat stress may facilitate the development of thermotolerant cultivars. Here, we compared two tomato processing cultivars, H4107 and H9780, that we found to be constantly differing in yield performance. Using field and temperature-controlled greenhouse experiments, we show that the observed difference in yield is attributed to the occurrence of heat stress conditions. In addition, fruit-set and seed production were significantly improved in the thermotolerant cultivar H4107, compared with H9780. Despite the general acceptance of pollen viability as a measure of thermotolerance, there was no difference in the percentage of viable pollen between H4107 and H9780 under either of the conditions tested. Therefore, processing tomato cultivars may present a particular case, in which other factors are central for heat stress tolerance. Our results also demonstrate the value of combining controlled with uncontrolled experimental settings, in order to identify heat stress-related responses and facilitate the development of thermotolerant processing tomato cultivars.

scholarly journals Application of stress susceptibility index and multivariate analysis of tomato (Solanum lycopersicum L.) to identify thermo-tolerant genotypes

2021 ◽  
Author(s):  
Archana K. A. ◽  
T. Pradeepkumar ◽  
Pratheesh P Gopinath ◽  
Santhoshkumar A. V.
Keyword(s):  
Multivariate Analysis ◽  
Heat Tolerance ◽  
Heat Waves ◽  
Pollen Viability ◽  
Deep Understanding ◽  
Reproductive Traits ◽  
Crop Productivity ◽  
Fruit Weight ◽  
Susceptibility Index ◽  
Stress Susceptibility

Abstract Climatic parameters have become key mechanisms in controlling crop productivity worldwide. The more frequency of heat waves urges the breeding for thermo-tolerance. The motive of this study was to furnish an accurate and deep understanding on the heat tolerance of reproductive key traits (flowers with exerted stigma, pollen viability, fruits set per cent and number of fruits per cluster), along with earliness (days to first fruit set) and yield traits (average fruit weight, pericarp thickness, number of fruits per plant and yield per plant) in tomato. The study reasoned 35 genotypes employing three no-identical analysis tools, ANOVA of field assessment, stress susceptibility index and multivariate analysis based on genetic diversity. Insights of genetic architecture of the reproductive traits under heat stress might improve our core understanding, and might have applied value. The study substantiated the essence of heat tolerance for the genotypes EC-620395, EC-620401, EC-620406 and EC-620410. Divergence analysis revealed five clusters corresponding to specific characters. Therefore on the ground of the investigation new breeding lines and breeding strategies can be implemented under changing environmental conditions with special reference to elevated temperature.

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 Identification of stable heat tolerance QTLs using inter-specific recombinant inbred line population derived from GPF 2 and ILWC 292

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0254957
Author(s):  
Ashutosh Kushwah ◽  
Dharminder Bhatia ◽  
Inderjit Singh ◽  
Mahendar Thudi ◽  
Gurpreet Singh ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Recombinant Inbred ◽  
Recombinant Inbred Lines ◽  
Pollen Viability ◽  
Reproductive Period ◽  
Snp Markers ◽  
Leaf Water Content ◽  
Days To Flowering ◽  
Significant Difference

Heat stress during reproductive stages has been leading to significant yield losses in chickpea (Cicer arietinum L.). With an aim of identifying the genomic regions or QTLs responsible for heat tolerance, 187 F8 recombinant inbred lines (RILs) derived from the cross GPF 2 (heat tolerant) × ILWC 292 (heat sensitive) were evaluated under late-sown irrigated (January-May) and timely-sown irrigated environments (November-April) at Ludhiana and Faridkot in Punjab, India for 13 heat tolerance related traits. The pooled ANOVA for both locations for the traits namely days to germination (DG), days to flowering initiation (DFI), days to 50% flowering (DFF), days to 100% flowering (DHF), plant height (PH), pods per plant (NPP), biomass (BIO), grain yield (YLD), 100-seed weight (HSW), harvest index (HI), membrane permeability index (MPI), relative leaf water content (RLWC) and pollen viability (PV)) showed a highly significant difference in RILs. The phenotyping data coupled with the genetic map comprising of 1365 ddRAD-Seq based SNP markers were used for identifying the QTLs for heat tolerance. Composite interval mapping provided a total of 28 and 23 QTLs, respectively at Ludhiana and Faridkot locations. Of these, 13 consensus QTLs for DG, DFI, DFF, DHF, PH, YLD, and MPI have been identified at both locations. Four QTL clusters containing QTLs for multiple traits were identified on the same genomic region at both locations. Stable QTLs for days to flowering can be one of the major factors for providing heat tolerance as early flowering has an advantage of more seed setting due to a comparatively longer reproductive period. Identified QTLs can be used in genomics-assisted breeding to develop heat stress-tolerant high yielding chickpea cultivars.

scholarly journals Antioxidant and Hormone Responses to Heat Stress in Two Kentucky Bluegrass Cultivars Contrasting in Heat Tolerance

2014 ◽  
Vol 139 (5) ◽  
pp. 587-596 ◽  
Author(s):  
Feifei Li ◽  
Da Zhan ◽  
Lixin Xu ◽  
Liebao Han ◽  
Xunzhong Zhang
Keyword(s):  
Heat Stress ◽  
Antioxidant Enzyme ◽  
Heat Tolerance ◽  
Poa Pratensis ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Limiting Factor ◽  
Antioxidant Enzyme Activities ◽  
Aba Content

Heat stress is a major limiting factor for growth of cool-season perennial grass species, and mechanisms of heat tolerance have not been well understood. This study was designed to investigate antioxidant enzyme and hormone metabolism responses to heat stress in two kentucky bluegrass (Poa pratensis L.) cultivars contrasting in heat tolerance. The plants were subjected to 20/20 °C [day/night (control)] or 38/30 °C [day/night (heat stress)] for 28 days in growth chambers. Heat stress increased leaf electrolyte leakage (EL) and malondialdehyde (MDA) with heat-tolerant cultivar EverGlade exhibiting lower levels of EL and MDA relative to heat-sensitive cultivar Kenblue under heat stress. Superoxide dismutase (SOD) and catalase (CAT) activity increased and then declined during 28 days of heat stress. Peroxidase (POD) and ascorbate peroxidase (APX) activity declined and then increased during heat stress. ‘EverGlade’ had greater activities of SOD, CAT, POD, and APX relative to ‘Kenblue’ under heat stress. In addition, ‘EverGlade’ had two additional SOD isozymes and three additional POD isozymes relative to ‘Kenblue’ under heat stress. Leaf abscisic acid (ABA) increased in response to heat stress. Leaf indole-3-acetic acid (IAA) increased and then declined during heat stress. ‘OverGlade’ had higher ABA and IAA content relative to ‘Kenblue’. At the end of heat stress, leaf IAA and ABA content were 27.8% and 73% higher in ‘EverGlade’ relative to ‘Kenblue’, respectively. The results indicated that antioxidant enzymes and the hormones (ABA and IAA) were associated with kentucky bluegrass heat tolerance. Selection and use of cultivars with higher IAA and ABA content and greater antioxidant enzyme activities may improve kentucky bluegrass growth and quality under heat stress.

scholarly journals Leaf Monoterpene Emission Limits Photosynthetic Downregulation under Heat Stress in Field-Grown Grapevine

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 181
Author(s):  
Massimo Bertamini ◽  
Michele Faralli ◽  
Claudio Varotto ◽  
Maria Stella Grando ◽  
Luca Cappellin
Keyword(s):  
Heat Stress ◽  
Vitis Vinifera ◽  
High Temperatures ◽  
Heat Tolerance ◽  
Global Climate ◽  
Crop Productivity ◽  
Field Trials ◽  
Co2 Assimilation ◽  
Monoterpene Emission

Rising temperature is among the most remarkably stressful phenomena induced by global climate changes with negative impacts on crop productivity and quality. It has been previously shown that volatiles belonging to the isoprenoid family can confer protection against abiotic stresses. In this work, two Vitis vinifera cv. ‘Chardonnay’ clones (SMA130 and INRA809) differing due to a mutation (S272P) of the DXS gene encoding for 1-deoxy-D-xylulose-5-phosphate (the first dedicated enzyme of the 2C-methyl-D-erythritol-4-phosphate (MEP) pathway) and involved in the regulation of isoprenoids biosynthesis were investigated in field trials and laboratory experiments. Leaf monoterpene emission, chlorophyll fluorescence and gas-exchange measurements were assessed over three seasons at different phenological stages and either carried out in in vivo or controlled conditions under contrasting temperatures. A significant (p < 0.001) increase in leaf monoterpene emission was observed in INRA809 when plants were experiencing high temperatures and over two experiments, while no differences were recorded for SMA130. Significant variation was observed for the rate of leaf CO2 assimilation under heat stress, with INRA809 maintaining higher photosynthetic rates and stomatal conductance values than SMA130 (p = 0.003) when leaf temperature increased above 30 °C. At the same time, the maximum photochemical quantum yield of PSII (Fv/Fm) was affected by heat stress in the non-emitting clone (SMA130), while the INRA809 showed a significant resilience of PSII under elevated temperature conditions. Consistent data were recorded between field seasons and temperature treatments in controlled environment conditions, suggesting a strong influence of monoterpene emission on heat tolerance under high temperatures. This work provides further insights on the photoprotective role of isoprenoids in heat-stressed Vitis vinifera, and additional studies should focus on unraveling the mechanisms underlying heat tolerance on the monoterpene-emitter grapevine clone.

scholarly journals Exploring Morpho-Physiological Variation for Heat Stress Tolerance in Tomato

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 347
Author(s):  
Samikshya Bhattarai ◽  
Joshua Harvey ◽  
Desire Djidonou ◽  
Daniel Leskovar
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Open Field ◽  
Electrolyte Leakage ◽  
Leaf Gas Exchange ◽  
Total Yield ◽  
Stress Conditions ◽  
Heat Injury ◽  
Injury Index ◽  
Heat Tolerant

Texas tomato production is vulnerable to extreme heat in the spring-summer cropping period, which is exacerbated by the lack of superior genetic materials that can perform well in such environments. There is a dire need for selecting superior varieties that can adapt to warm environments and exhibit high yield stability under heat stress conditions. This research aimed at identifying heat-tolerant varieties under heat-stress conditions in controlled and open-field environments and was carried out in three stages. For the first experiment, 43 varieties were screened based on yield responses in natural open-field environment. From those, 18 varieties were chosen and exposed to control (greenhouse: 26/20 °C) and constant heat-stress (growth-chamber: 34/24 °C) conditions for three months. Measurements were done for chlorophyll fluorescence, chlorophyll content (SPAD), plant height, stem diameter and heat injury index (HII). The last experiment was conducted in an open field with a pool of varieties selected from the first and second experiments. Leaf gas exchange, leaf temperature, chlorophyll fluorescence, SPAD value, electrolyte leakage, heat injury index and yield were assessed. From the combined studies, we concluded that heat-tolerant genotypes selected by using chlorophyll fluorescence and HII in controlled heat-stress conditions also exhibited heat-tolerance in open-field environments. Electrolyte leakage and HII best distinguished tomato varieties in open-field environments as plants with low electrolyte leakage and HII had higher total yield. 'Heat Master,' 'New Girl,' 'HM-1823,' 'Rally,' 'Valley Girl,' 'Celebrity,' and 'Tribeca' were identified as high heat-tolerant varieties. Through trait correlation analysis we provide a better understanding of which traits could be useful for screening and breeding other heat-tolerant tomato varieties.

scholarly journals Genotype-by-environment interaction in Holstein heifer fertility traits using single-step genomic reaction norm models

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Rui Shi ◽  
Luiz Fernando Brito ◽  
Aoxing Liu ◽  
Hanpeng Luo ◽  
Ziwei Chen ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cattle ◽  
Candidate Genes ◽  
Heat Tolerance ◽  
Reaction Norm ◽  
Single Step ◽  
Conception Rate ◽  
Critical Periods ◽  
Genotype By Environment ◽  
Fertility Traits

Abstract Background The effect of heat stress on livestock production is a worldwide issue. Animal performance is influenced by exposure to harsh environmental conditions potentially causing genotype-by-environment interactions (G × E), especially in highproducing animals. In this context, the main objectives of this study were to (1) detect the time periods in which heifer fertility traits are more sensitive to the exposure to high environmental temperature and/or humidity, (2) investigate G × E due to heat stress in heifer fertility traits, and, (3) identify genomic regions associated with heifer fertility and heat tolerance in Holstein cattle. Results Phenotypic records for three heifer fertility traits (i.e., age at first calving, interval from first to last service, and conception rate at the first service) were collected, from 2005 to 2018, for 56,998 Holstein heifers raised in 15 herds in the Beijing area (China). By integrating environmental data, including hourly air temperature and relative humidity, the critical periods in which the heifers are more sensitive to heat stress were located in more than 30 days before the first service for age at first calving and interval from first to last service, or 10 days before and less than 60 days after the first service for conception rate. Using reaction norm models, significant G × E was detected for all three traits regarding both environmental gradients, proportion of days exceeding heat threshold, and minimum temperature-humidity index. Through single-step genome-wide association studies, PLAG1, AMHR2, SP1, KRT8, KRT18, MLH1, and EOMES were suggested as candidate genes for heifer fertility. The genes HCRTR1, AGRP, PC, and GUCY1B1 are strong candidates for association with heat tolerance. Conclusions The critical periods in which the reproductive performance of heifers is more sensitive to heat stress are trait-dependent. Thus, detailed analysis should be conducted to determine this particular period for other fertility traits. The considerable magnitude of G × E and sire re-ranking indicates the necessity to consider G × E in dairy cattle breeding schemes. This will enable selection of more heat-tolerant animals with high reproductive efficiency under harsh climatic conditions. Lastly, the candidate genes identified to be linked with response to heat stress provide a better understanding of the underlying biological mechanisms of heat tolerance in dairy cattle.

An ER–Golgi Tethering Factor SLOH4/MIP3 Is Involved in Long-term Heat Tolerance of Arabidopsis

2020 ◽  
Author(s):  
Kazuho Isono ◽  
Ryo Tsukimoto ◽  
Satoshi Iuchi ◽  
Akihisa Shinozawa ◽  
Izumi Yotsui ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Secretory Proteins ◽  
Wild Type ◽  
Additional Function ◽  
Transcript Levels ◽  
Unfolded Protein ◽  
In The Wild ◽  
Protein Response

Abstract Plants are often exposed not only to short-term (S-) heat stress but also to diurnal long-term (L-) heat stress over several consecutive days. To reveal the mechanisms underlying L-heat stress tolerance, we here used a forward genetic screening for sensitive to long-term heat (sloh) mutants and isolated sloh4. The mutant was hypersensitive to L- but not S-heat stress. The causal gene of sloh4 was identical to MIP3 encoding a member of the MAIGO2 (MAG2) tethering complex, which is composed of the MAG2, MIP1, MIP2, and MIP3 subunits and is localized at the endoplasmic reticulum (ER) membrane. Although sloh4/mip3 was hypersensitive to L-heat stress, the sensitivity of the mag2-3 and mip1–1 mutants was similar to that of the wild type. Under L-heat stress, the ER stress and the following unfolded protein response (UPR) were more pronounced in sloh4 than in the wild type. Transcript levels of bZIP60-regulated UPR genes were strongly increased in sloh4 under L-heat stress. Two processes known to be mediated by INOSITOL REQUIRING ENZYME1 (IRE1)—accumulation of the spliced bZIP60 transcript and a decrease in the transcript levels of PR4 and PRX34, encoding secretory proteins—were observed in sloh4 in response to L-heat stress. These findings suggest that misfolded proteins generated in sloh4 under L-heat stress may be recognized by IRE1 but not bZIP28, resulting in initiation of the UPR via activated bZIP60. Therefore, it would be possible that only MIP3 in MAG2 complex has an additional function in L-heat tolerance, which is not related to the ER–Golgi vesicle tethering.

Sign in / Sign up

Export Citation Format

Share Document