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 Molecular Identification and Characterization of Heat-Stress-Responsive Microgametogenesis Genes in Tomato and Sorghum - A Feasibility Study

2007 ◽  
Author(s):  
Nurit Firon ◽  
Prem Chourey ◽  
Etan Pressman ◽  
Allen Hartwell ◽  
Kenneth J. Boote
Keyword(s):  
Heat Stress ◽  
Crop Yields ◽  
Pollen Grains ◽  
High Sensitivity ◽  
Stress Conditions ◽  
Flower Opening ◽  
Pollen Quality ◽  
Heat Tolerant ◽  
Close Sequence ◽  
Shock Proteins

Exposure to higher than optimal temperatures - heat-stress (HS) - is becoming increasingly common to all crop plants worldwide. Heat stress coinciding with microgametogenesis, especially during the post-meiotic phase that is marked by starch biosynthesis, is often associated with starch-deficient pollen and male sterility and ultimately, greatly reduced crop yields. The molecular basis for the high sensitivity of developing pollen grains, on one hand, and factors involved in pollen heat-tolerance, on the other, is poorly understood. The long-term goal of this project is to provide a better understanding of the genes that control pollen quality under heat-stress conditions. The specific objectives of this project were: (1) Determination of the threshold heat stress temperature(s) that affects tomato and sorghum pollen quality whether: a) Chronic mild heat stress conditions (CMHS), or b) Acute heat stress (AHS). (2) Isolation of heat-responsive, microgametogenesis-specific sequences. During our one-year feasibility project, we have accomplished the proposed objectives as follows: Objectrive 1: We have determined the threshold HS conditions in tomato and sorghum. This was essential for achieving the 2nd objective, since our accumulated experience (both Israeli and US labs) indicate that when temperature is raised too high above "threshold HS levels" it may cause massive death of the developing pollen grains. Above-threshold conditions have additional major disadvantages including the "noise" caused by induced expression of genes involved in cell death and masking of the differences between heatsensitive and heat-tolerant pollen grains. Two different types of HS conditions were determined: a) Season-long CMHS conditions: 32/26°C day/night temperatures confirmed in tomato and 36/26°C day maximum/night minimum temperatures in sorghum. b) Short-term AHS: In tomato, 2 hour exposure to 42-45°C (at 7 to 3 days before anthesis) followed by transfer to 28/22±2oC day/night temperatures until flower opening and pollen maturation, caused 50% reduced germinating pollen in the heat-sensitive 3017 cv.. In sorghum, 36/26°C day/night temperatures 10 to 5 days prior to panicle emergence, occurring at 35 days after sowing (DAS) in cv. DeKalb28E, produced starch-deficient and sterile pollen. Objective 2: We have established protocols for the high throughput transcriptomic approach, cDNA-AFLP, for identifying and isolating genes exhibiting differential expression in developing microspores exposed to either ambient or HS conditions and created a databank of HS-responsivemicrogametogenesis-expressed genes. A subset of differentially displayed Transcript-Derived Fragments (TDFs) that were cloned and sequenced (35 & 23 TDFs in tomato and sorghum, respectively) show close sequence similarities with metabolic genes, genes involved in regulation of carbohydrate metabolism, genes implicated in thermotolerance (heat shock proteins), genes involved in long chain fatty acids elongation, genes involved in proteolysis, in oxidation-reduction, vesicle-mediated transport, cell division and transcription factors. T-DNA-tagged Arabidopsis mutants for part of these genes were obtained to be used for their functional analysis. These studies are planned for a continuation project. Following functional analyses of these genes under HS – a valuable resource of genes, engaged in the HS-response of developing pollen grains, that could be modulated for the improvement of pollen quality under HS in both dicots and monocots and/or used to look for natural variability of such genes for selecting heat-tolerant germplasm - is expected.

scholarly journals Penconazole Induced Heat Tolerance in Scots Pine (Pinus sylvestris) and Evergreen Oak (Quercus ilex)

2010 ◽  
Vol 36 (5) ◽  
pp. 212-220
Author(s):  
Glynn Percival ◽  
Kelly Noviss
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Electrolyte Leakage ◽  
Quercus Ilex ◽  
Recovery Rates ◽  
Photosynthetic System ◽  
Heat Damage ◽  
Evergreen Oak

The ability of penconazole, a triazole fungicide derivative, to protect against and ameliorate heat stress was studied in evergreen oak (Quercus ilex) and Scots pine (Pinus sylvestris). Under laboratory conditions, heat damage to the leaf photosynthetic system based on the stability of the chlorophyll a/b light-harvesting complex within photosystem II (chlorophyll fluorescence Fo responses) and leaf photochemical efficiency (chlorophyll fluorescence Fv/Fm emissions) of detached leaves was constantly less in penconazole treated trees. In both species, greatest protection of the leaf photosynthetic system to heat induced disorders was achieved by application of penconazole at a concentration of 30 g per liter of water compared to penconazole applied at a concentration of 0.15 or 0.45 g per liter of water. Subjecting containerized trees of both species to 10 minutes at 50°C significantly reduced tree vitality with respect to chlorophyll fluorescence Fo and Fv/ Fm emissions, total foliar chlorophylls, leaf photosynthetic rates (Pn) and significantly increased damage to cellular membrane integrity as manifest by higher leaf electrolyte leakage and visual leaf necrosis between stressed and non-heat stressed well-watered trees. The influence of penconazole applied immediately after heat stress on the pattern of recovery over the following twelve weeks demonstrated penconazole treated trees were the most capable of recovery. With respect to chlorophyll fluorescence Fo and leaf electrolyte leakage values recovery rates of heat damaged trees treated with penconazole ranged from 20%–50% higher than non-triazole treated control trees. In all cases nonpenconazole treated control trees had the least capacity for recovery. Regardless of species, height, leaf area, root, shoot, and total plant dry weight were, in virtually all instances, greater than non-penconazole treated controls. The tactical use of the triazole derivative penconazole as an ameliorant against heat damage and recovery from heat stress in Scots pine and evergreen oak would be of benefit to improve tree recovery rates and growth. From a practical point of view penconazole at 30 g a.i. per liter of water is suggested based on the results of this study.

scholarly journals Using Volatile Emissions and Chlorophyll Fluorescence as Indicators of Heat Injury in Apples

2001 ◽  
Vol 126 (6) ◽  
pp. 771-777 ◽  
Author(s):  
Jun Song ◽  
Lihua Fan ◽  
Charles F. Forney ◽  
Michael A. Jordan
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Ethyl Acetate ◽  
Correlation Coefficients ◽  
Heat Treatments ◽  
Heat Injury ◽  
Volatile Emissions ◽  
Flesh Browning ◽  
Nondestructive Measurements ◽  
Volatile Production

Volatile emissions and chlorophyll fluorescence were investigated as potential signals of heat injury for apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] fruit. `McIntosh', `Cortland', `Jonagold', and `Northern Spy' apples were exposed to 46 °C for 0, 4, 8, or 12 hours (heat treatments). Following treatments, fruit were kept at 20 °C and evaluated after 1, 2, 4, or 7 days. Heat treatments induced volatile production including ethanol and ethyl acetate. The 8 and 12 hours heat treatments increased ethanol and ethyl acetate production in all four cultivars by as much as 170- and 11-fold, respectively, 1 day after treatments. Heat treatments also reduced ethylene production and chlorophyll fluorescence. Heat for 12 hours caused serious flesh browning. Among the cultivars investigated, `Northern Spy' and `McIntosh' were most susceptible to heat stress based on the degree of flesh browning. Correlation coefficients of heat stress induced ethanol emission and chlorophyll fluorescence with flesh browning were 0.82 and -0.66, respectively. The nondestructive measurements of ethanol emission and chlorophyll fluorescence have potential to identify stressed fruit with reduced quality or compromised storage life.

Effects of exogenous application of abscisic acid on membrane stability, osmotic adjustment, photosynthesis and hormonal status of two lucerne (Medicago sativa L.) genotypes under high temperature stress and drought stress

2014 ◽  
Vol 65 (3) ◽  
pp. 274 ◽  
Author(s):  
Yuan An ◽  
Peng Zhou ◽  
Jinfeng Liang
Keyword(s):  
Heat Stress ◽  
Photosynthetic Rate ◽  
Electrolyte Leakage ◽  
Physiological Responses ◽  
Proline Content ◽  
Water Conditions ◽  
Medicago Sativa L ◽  
Heat Tolerant ◽  
Soil Water Conditions ◽  
Aba Content

This study was designed to examine effects of high temperature, drought and exogenous abscisic acid (ABA) on membrane stability, osmotic adjustment, photosynthesis and the hormone status of two lucerne (alfalfa, Medicago sativa L.) genotypes contrasting in heat tolerance: Ameristand 801S (AS801) (heat-tolerant), and Aohan (heat-sensitive), The results showed that AS801 had lower electrolyte leakage, but higher chlorophyll content, net photosynthetic rate, stomatal conductance, proline content, ABA content and zeatin riboside (ZR) content than Aohan during 72 h of heat stress under well-watered conditions. Under drought conditions, however, only proline content and ZR content in roots, electrolyte leakage in leaves and roots, net photosynthetic rate, and ABA content were significantly different between the two genotypes. A foliar application of ABA to heat-stressed plants significantly decreased electrolyte leakage and stomatal conductance, and increased recovery in growth and leaf water potential in the two genotypes under both watering conditions. The other physiological responses measured differed under drought or well-watered conditions, and appeared to be genotype-specific. These results suggest that the physiological responses of heat-sensitive and heat-tolerant lucerne to heat stress under different soil-water conditions varied. The heat-induced changes in proline accumulation in roots, electrolyte leakage in leaves and roots, and photosynthetic rate could serve as early instant stress indicators for evaluating the tolerance of lucerne genotypes to heat stress under different soil water conditions.

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

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

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

Identification of vegetative heat-tolerant upland cotton (Gossypium hirsutumL.) germplasm utilizing chlorophyll fluorescence measurement during heat stress

2013 ◽  
Vol 133 (2) ◽  
pp. 250-255 ◽  
Author(s):  
Tingting Wu ◽  
David B. Weaver ◽  
Robert D. Locy ◽  
Scott McElroy ◽  
Edzard van Santen
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Upland Cotton ◽  
Fluorescence Measurement ◽  
Heat Tolerant

Pollen grains of heat tolerant tomato cultivars retain higher carbohydrate concentration under heat stress conditions

2006 ◽  
Vol 109 (3) ◽  
pp. 212-217 ◽  
Author(s):  
N. Firon ◽  
R. Shaked ◽  
M.M. Peet ◽  
D.M Pharr ◽  
E. Zamski ◽  
...  
Keyword(s):  
Heat Stress ◽  
Pollen Grains ◽  
Stress Conditions ◽  
Carbohydrate Concentration ◽  
Tomato Cultivars ◽  
Heat Tolerant

scholarly journals Effects of post-anthesis heat stress on stem reserves mobilization, canopy temperature depression and floret sterility of wheat cultivars

2010 ◽  
Vol 39 (1) ◽  
pp. 51-55 ◽  
Author(s):  
S Sikder ◽  
NK Paul
Keyword(s):  
Heat Stress ◽  
Canopy Temperature ◽  
Stress Conditions ◽  
Grain Weight ◽  
Wheat Cultivars ◽  
Canopy Temperature Depression ◽  
Heat Tolerant ◽  
Growing Conditions ◽  
Stem Reserves ◽  
Temperature Depression

Testing of four heat tolerant (Gourab, Sourav, Kanchan and Shatabdi) and two heat sensitive (Sonora and Kalyansona) wheat cultivars under normal and late growing post-anthesis heat stress conditions revealed higher pre-anthesis stem reserves mobilization to the final grain weight and floret sterility in heat sensitive cultivars compared to heat tolerant cultivars. The heat tolerant cultivars showed higher canopy temperature depression than the heat sensitive cultivars in both the growing conditions indicating the higher ability of heat tolerant cultivars to maintain cooler canopy environment than the heat sensitive ones.Key words: Post-anthesis; Heat stress; Floret sterility; Canopy temperature; Mobilization DOI: 10.3329/bjb.v39i1.5526Bangladesh J. Bot. 39(1): 51-55, 2010 (June)

scholarly journals Physiological and genetic characterization of heat stress effects in a common bean RIL population

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249859
Author(s):  
Yulieth Vargas ◽  
Victor Manuel Mayor-Duran ◽  
Hector Fabio Buendia ◽  
Henry Ruiz-Guzman ◽  
Bodo Raatz
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Common Bean ◽  
Grain Quality ◽  
Pollen Viability ◽  
Stress Conditions ◽  
Future Climate Change ◽  
Reproductive Phase ◽  
Ril Population ◽  
Heat Tolerant

Heat stress is a major abiotic stress factor reducing crop productivity and climate change models predict increasing temperatures in many production regions. Common bean (Phaseolus vulgaris L.) is an important crop for food security in the tropics and heat stress is expected to cause increasing yield losses. To study physiological responses and to characterize the genetics of heat stress tolerance, we evaluated the recombinant inbred line (RIL) population IJR (Indeterminate Jamaica Red) x AFR298 of the Andean gene pool. Heat stress (HS) conditions in the field affected many traits across the reproductive phase. High nighttime temperatures appeared to have larger effects than maximum daytime temperatures. Yield was reduced compared to non-stress conditions by 37% and 26% in 2016 and 2017 seasons, respectively. The image analysis tool HYRBEAN was developed to evaluate pollen viability (PolVia). A significant reduction of PolVia was observed in HS and higher viability was correlated with yield only under stress conditions. In susceptible lines the reproductive phase was extended and defects in the initiation of seed, seed fill and seed formation were identified reducing grain quality. Higher yields under HS were correlated with early flowering, high pollen viability and effective seed filling. Quantitative trait loci (QTL) analysis revealed a QTL for both pod harvest index and PolVia on chromosome Pv05, for which the more heat tolerant parent IJR contributed the positive allele. Also, on chromosome Pv08 a QTL from IJR improved PolVia and the yield component pods per plant. HS affected several traits during the whole reproductive development, from floral induction to grain quality traits, indicating a general heat perception affecting many reproductive processes. Identification of tolerant germplasm, indicator traits for heat tolerance and molecular tools will help to breed heat tolerant varieties to face future climate change effects.

scholarly journals Combining Ability and Gene Action Controlling Grain Yield and Its Related Traits in Bread Wheat under Heat Stress and Normal Conditions

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1450
Author(s):  
Mohamed M. Kamara ◽  
Khaled M. Ibrahim ◽  
Elsayed Mansour ◽  
Ahmed M. S. Kheir ◽  
Mousa O. Germoush ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Chlorophyll Content ◽  
Plant Height ◽  
Bread Wheat ◽  
Gene Action ◽  
Stress Conditions ◽  
Wheat Genotypes ◽  
Sowing Dates ◽  
Heat Tolerant

High temperature is a major environmental stress that devastatingly affects wheat production. Thenceforth, developing heat-tolerant and high-yielding wheat genotypes has become more critical to sustaining wheat production particularly under abrupt climate change and fast-growing global population. The present study aimed to evaluate parental genotypes and their cross combinations under normal and heat stress conditions, exploring their diversity based on dehydration-responsive element-binding 2 gene (DREB, stress tolerance gene in response to abiotic stress) in parental genotypes, and determining gene action controlling yield traits through half-diallel analysis. Six diverse bread wheat genotypes (local and exotic) and their 15 F1 hybrids were evaluated at two different locations under timely and late sowing dates. Sowing date, location, genotype, and their interactions significantly impacted the studied traits; days to heading, chlorophyll content, plant height, grain yield, and its attributes. Cluster analysis classified the parents and their crosses into four groups varying from heat-tolerant to heat-sensitive based on heat tolerance indices. The parental genotypes P2 and P4 were identified as an excellent source of beneficial alleles for earliness and high yielding under heat stress. This was corroborated by DNA sequence analysis of DREB transcription factors. They were the highest homologies for dehydrin gene sequence with heat-tolerant wheat species. The hybrid combinations of P1 × P5, P1 × P6, P2 × P4, and P3 × P5 were detected to be good specific combiners for grain yield and its attributes under heat stress conditions. These designated genotypes could be used in wheat breeding for developing heat-tolerant and climate-resilient cultivars. The non-additive genetic variances were preponderant over additive genetic variances for grain yield and most traits under both sowing dates. The narrow-sense heritability ranged from low to moderate for most traits. Strong positive associations were detected between grain yield and each of chlorophyll content, plant height, number of grains/spike, and thousand-grain weights, which suggest their importance for indirect selection under heat stress, especially in early generations, due to the effortlessness of their measurement.

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