scholarly journals HEAT TOLERANCE OF SELECTED TOMATO CULTIVARS AND GERMPLASM LINES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1149a-1149
Author(s):  
Aref A. Abdul-Baki
Keyword(s):  
High Temperature ◽  
Seed Production ◽  
Heat Tolerance ◽  
Evaluation Criteria ◽  
Breeding Lines ◽  
Temperature Heat ◽  
Tomato Cultivars ◽  
Heat Tolerant ◽  
Viable Seeds ◽  
Better Than

Selected breeding lines and cultivars of tomatoes (Lycopersicon esculentrum Mill.) were evaluated for heat tolerance in the greenhouse (39°C day and 28°C night) and field using flowering, fruit-set, yield, fruit quality, and seed production as criteria. Under high temperature, heat tolerant lines performed better than the other two groups in all evaluation criteria except for seed production. The opposite was found under normal field conditions where heat sensitive commercial cultivars outyielded the heat tolerant lines and cultivars. Production of viable seeds under high temperature was severely reduced regardless of the heat tolerance level exhibited by the line or cultivar. Some of the heat tolerant lines could provide valuable sources of plant material for physiological studies to establish the molecular basis of heat tolerance and also could provide excellent germplasm sources for breeding heat tolerant tomato cultivars.

scholarly journals Tolerance of Tomato Cultivars and Selected Germplasm to Heat Stress

1991 ◽  
Vol 116 (6) ◽  
pp. 1113-1116 ◽  
Author(s):  
Aref A. Abdul-Baki
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Fruit Set ◽  
Breeding Lines ◽  
Tomato Cultivars ◽  
Heat Tolerant ◽  
Viable Seeds ◽  
Molecular Bases ◽  
The Relationship

Nine heat-tolerant tomato [Lycopersicon esculentum (Mill.)] breeding lines, four heat-tolerant cultivars, and four heat-sensitive cultivars were evaluated in the greenhouse under high temperature (39C day/28C night) and in the field. Criteria for heat tolerance included flowering, fruit set, yield, fruit quality, and seed production. Under high-temperature conditions, the group of heat-tolerant lines, the heat-tolerant cultivars, and the heat-sensitive cultivars produced, respectively, the following per plant: flowers, 186, 94, and 55; fruit set 70%, 52%, and 30%; yield, 410, 173, and 11 g; and normal mature fruit, 72%, 37%, and 7%. Yields of heat-tolerant lines under high temperature in the greenhouse ranged from 118% to 31% of their respective yields in the field. Yields of heat-tolerant cultivars were 62% of those in the field. In contrast, yields of heat-sensitive cultivars under high temperature were < 1% of their respective yields in the field. High temperature induced flower abscission, reduced fruit set and yield, and increased the incidence of abnormalities. Major fruit abnormalities with high temperatures included cracks, blossomed rot, watery tissue, and small, immature fruits. Production of viable seeds under the high-temperature regime was severely reduced or totally inhibited regardless of the heat-tolerance level exhibited by the line or cultivar. The failure of heat-sensitive and most heat-tolerant cultivars or lines to produce viable seeds under such a high temperature suggests that a lower level of heat stress than that applied in these experiments could allow the production of enough seeds to test the relationship between heat tolerance in a genotype and its ability to produce viable seeds under high temperature. The results indicate that certain lines have high tolerance to heat and, therefore, could provide valuable sources of plant material for physiological studies to establish the physiological and molecular bases of heat tolerance. Some of the heat-tolerant lines might also serve as excellent germplasm sources in breeding heat-tolerant tomato cultivars.

scholarly journals Effect of Heat Treatment on Physiological and Recovery Growth Status of Two Tomato Cultivars With Different Heat Susceptibility

2021 ◽  
Author(s):  
Sherzod Nigmatullayevich Rajametov ◽  
Eun Young Yang ◽  
Hyo Bong Jeong ◽  
Myeong Cheoul Cho ◽  
Soo-Young Chae ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Stress Tolerance ◽  
Heat Tolerance ◽  
Fruit Set ◽  
Fruit Size ◽  
Seedling Stage ◽  
Screening Methods ◽  
Tomato Cultivars ◽  
Heat Tolerant

High temperature seriously effects on plant vegetative and reproductive development and reduces productivity of plants, while to increase crop yield is the main target in most crop heat stress tolerance improvement breeding programs, not just survival, under high temperature. Our aim was to compare temperature stress tolerance in two commercial tomato cultivars &ldquo;Dafnis&rdquo; (big fruit size) and &ldquo;Minichal&rdquo; (cherry fruit size) to develop early screening methods and find out survival rate and physiological responses of tomato cultivars on high temperature (40&deg;C and within 70% RH, day/night) in 4-5 true leaf seedling stage- (4LS) and identifies the linkage of heat tolerance with fruit set and leaf heat damage rates (LHD) in seedling stage with subsequent vegetative traits at recovery. Results showed that heat stress significantly affected on physiological-chemical and vegetative parameters of seedlings regardless of tomato cultivars. Survival and the threshold level of high temperature tolerance in the seedlings of cv. &ldquo;Dafnis&rdquo; and &ldquo;Minichal&rdquo; were identified on days 7 and 9, respectively. Our findings revealed that photosynthesis (PN, Gs, Ci, Tr) parameters were increased and CHL content persisted steady value in cv. &ldquo;Minichal&rdquo; during heat stress period, however EC and RPL rates were lower than cv. &ldquo;Dafnis&rdquo;. Heat stress reduced the SFW in both cultivars in seedling stage, but PH and RFW were significantly decreased in the heat tolerant cv. &ldquo;Minichal&rdquo;, whereas this parameters were not significantly ranged in the heat susceptible cv. &ldquo;Dafnis&rdquo;. Additionally, there no found linkage between vegetative parameters with decreasing of PN and CHL rates during HT of seedlings. In plants of cv. &ldquo;Minichal&rdquo; with LHD-25, 50 and 75% were no found significant differences in PH, whereas in cv. &ldquo;Dafnis&rdquo; significant differences were determined in plants with LHD-75%, and the significant differences in rates of SFW and RFW were observed in plants of cv. &ldquo;Dafnis&rdquo; having LHD-75% for 28 days of recovery at NT condition. Taken together, we concluded that heat stress affected on physiological parameters regardless of tolerance level, and to identify heat tolerant genotype in tomato breeding program, screening and selection genotypes have to be evaluated at the vegetative and reproductive stages with consideration fruit size types. Since we could not find linkage between heat tolerances in seedling stage with fruit set at the reproductive stage and fruit set cannot be used as a general predictor of heat tolerance.

scholarly journals Genetics and Breeding of Heat Tolerance in Rice

2021 ◽  
pp. 203-220
Author(s):  
Changrong Ye ◽  
Xiaolin Li ◽  
Edilberto Redoña ◽  
Tsutomu Ishimaru ◽  
Krishna Jagadish
Keyword(s):  
High Temperature ◽  
Heat Tolerance ◽  
Large Scale ◽  
Heat Waves ◽  
Rice Varieties ◽  
Breeding Lines ◽  
Donor Identification ◽  
Heat Tolerant ◽  
Sterile Pollen ◽  
World Food Security

AbstractExtreme weather events, especially heat waves, have become more frequent with global warming. High temperature significantly affects world food security by decreasing crop yield. Rice is intensively planted in tropical and subtropical areas in Asia, where high temperature has become a major factor affecting rice production. Rice is sensitive to high temperature, especially at booting and flowering stages. Rice varieties tolerant of high temperature are rare, and only a few heat-tolerant rice varieties have been identified. High temperature at booting and flowering stages causes sterile pollen, decreased pollen shedding, and poor pollen germination, which finally lead to a yield decrease. Heat-tolerant QTLs have been identified in different studies, but new breeding lines with considerable heat tolerance have not been bred using identified heat-tolerance donors and QTLs. Research on heat-tolerant donor identification, QTL mapping, gene cloning, and large-scale phenotyping technology is important for developing heat-tolerant rice varieties.

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 &lt; 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 Targeting Gene Combinations for Broad-spectrum Rust Resistance in Heat-tolerant Snap Beans Developed for Tropical Environments

2010 ◽  
Vol 135 (6) ◽  
pp. 521-532 ◽  
Author(s):  
Charles J. Wasonga ◽  
Marcial A. Pastor-Corrales ◽  
Timothy G. Porch ◽  
Phillip D. Griffiths
Keyword(s):  
Puerto Rico ◽  
Heat Tolerance ◽  
Rust Resistance ◽  
Eastern Africa ◽  
Snap Bean ◽  
Breeding Lines ◽  
Snap Beans ◽  
Tropical Environments ◽  
Heat Tolerant ◽  
Rust Resistance Genes

Common bean rust disease (caused by Uromyces appendiculatus) and high temperatures (heat stress) limit snap bean (Phaseolus vulgaris) production in many tropical and temperate regions. We have developed snap bean lines combining broad-spectrum rust resistance with heat tolerance for tropical agroecosystems. Eight breeding populations were developed by hybridizing BelJersey-RR-15 and BelFla-RR-1 (each possessing the Ur-4 and Ur-11 rust resistance genes) and the heat-tolerant snap bean breeding lines HT601, HT603, HT608, and HT611. F2–F4 generations of the populations were evaluated under greenhouse conditions and selected for heat tolerance while simultaneously selecting for the rust resistance genes Ur-4 and Ur-11. Three heat-tolerant F5 lines, which were homozygous for Ur-4 and Ur-11 genes, were selected together with a rust-resistant but heat-sensitive control. These and 12 cultivars adapted to different geographical regions were evaluated for their reaction to rust and yield at six contrasting field sites in eastern Africa and their response to high temperature verified in Puerto Rico. Rust incidence and severity was high at three of the trial sites in eastern Africa. Two of the 12 cultivars were resistant to rust at most of these sites, and three of the four breeding lines were resistant at all sites. The Ur-11 gene effectively conferred rust resistance at all sites. Yield in Puerto Rico was strongly correlated (R2 = 0.71, P < 0.001) with that of the hottest site in eastern Africa, highlighting the similarity in genotypic response to high temperatures at the two distinct sites. The newly developed rust-resistant and heat-tolerant breeding lines showed stable yield at the eastern Africa sites with contrasting mean temperatures compared with the cultivars presently grown in the region. Two of these lines, HT1 and HT2, were confirmed to be homozygous for Ur-4 and Ur-11 and with high heat tolerance under both greenhouse and field environments. This research validates the effectiveness of targeted rust resistance gene combinations for tropical environments and the effective selection of high temperature tolerance traits correlating across multiple environments. The breeding lines HT1 and HT2 developed in this research could be used to improve snap beans for the tropics and other environments with similar constraints.

scholarly journals Ergot Resistant Tetraploid Bahiagrass and Fungicide Effects on Seed Yield and Quality

2015 ◽  
Vol 16 (2) ◽  
pp. 56-62 ◽  
Author(s):  
Esteban Rios ◽  
Ann Blount ◽  
Philip Harmon ◽  
Cheryl Mackowiak ◽  
Kevin Kenworthy ◽  
...  
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Seed Quality ◽  
Reproductive Efficiency ◽  
Wild Type ◽  
University Of Florida ◽  
Breeding Lines ◽  
Yield And Quality ◽  
The University ◽  
Better Than

Seed production is a critical component in agricultural systems based on bahiagrass and ergot has been reported to significantly reduce seed quality in tetraploid cultivars. Seed yield and quality are important traits to evaluate in the advanced breeding lines developed at the University of Florida. Resistance to ergot was assessed in seven tetraploid bahiagrass breeding lines and the cultivar Argentine. Tebuconazole and pyraclostrobin also were evaluated for managing ergot and increasing seed quality. Argentine and two tetraploid hybrids (Hyb1 and Hyb2) showed the highest levels of ergot severity and incidence. Three wild-type bahiagrass lines (WT-2, WT-4 and WT-5) performed significantly better than Argentine and could be considered resistant to ergot. Anthesis was the critical stage in relation to ergot infection, and a single application of tebuconazole at anthesis reduced ergot severity; however, neither fungicide was able to reduce ergot incidence. Tebuconazole and pyraclostrobin improved seed set, and reproductive efficiency was 2.4% higher after the application of tebuconazole. The slight increase in reproductive efficiency following fungicide application may not be economically justifiable for seed production in bahiagrass. Three advanced tetraploid breeding lines (Hyb1, WT-3, and WT-5) exhibited adequate seed production to be considered for cultivar release. Accepted for publication 24 February 2015. Published 17 April 2015.

scholarly journals 612 The Relationship of Pollen Development and Release to Fruit and Seed Production in Tomato Cultivars Exposed to Heat Stress at Varying Humidity Levels

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 502E-503
Author(s):  
M.M. Peet ◽  
C. Clement ◽  
S. Sato
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Relative Humidity ◽  
Seed Production ◽  
Seed Development ◽  
Pollen Development ◽  
Fruit Weight ◽  
Tomato Cultivars ◽  
Pollen Release ◽  
Relationship Of

Starting 2 weeks before anthesis of the first flower, tomato cultivars (Lycopersicon esculentum Mill.) differing in heat tolerance were exposed to mild heat stress (31/24 vs. 28/22 °C) at three levels of relative humidity (30%, 60%, and 90%) in controlled environment chambers at the Duke Univ. Phytotron. Pollen development in the anthers was followed cytologically, pollen release was measured at anthesis, and seed production and fruit weight were measured as fruit matured. Fruit and seed development were best at 60%RH and 28/22 °C and worst at 90% RH and 31/24. Seed development was poor at 31/24 °C at all humidity levels. It was also poor at 28/22 in the 90% RH treatment. Low relative humidity had a greater negtive effect on fruit and seed production and on cytological development in plants grown at high temperature. Pollen release was also reduced at 90% RH, with virtually no pollen released at 31/24 °C. Cytological examinations revealed developmental anomolies in pollen in some, but not all cultivars at 90% and 30% RH. Plant height was also affected by the treatments, with much taller plants in the high-temperature, high-humidity treatments.

scholarly journals Heat-induced Leaf Senescence and Hormonal Changes for Thermal Bentgrass and Turf-type Bentgrass Species Differing in Heat Tolerance

2007 ◽  
Vol 132 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Yan Xu ◽  
Bingru Huang
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Leaf Senescence ◽  
Heat Tolerance ◽  
Photochemical Efficiency ◽  
Creeping Bentgrass ◽  
Zeatin Riboside ◽  
Hormonal Changes ◽  
Heat Tolerant ◽  
Aba Content

Leaf senescence can be induced by many environmental stresses, including supraoptimal temperatures. The objectives of this study were to evaluate leaf senescence induced by heat stress for two Agrostis species contrasting in heat tolerance and to examine whether heat-induced leaf senescence in both species was associated with changes in three major senescence-related hormones: ethylene, abscisic acid (ABA), and cytokinins. Plants of heat-tolerant rough bentgrass (Agrostis scabra Willd.) and heat-sensitive creeping bentgrass (Agrostis stolonifera L.) were exposed to 35/30 °C (day/night) (high temperature) or 20/15 °C (control) for 35 d in growth chambers. Turf quality, photochemical efficiency (Fv/Fm), and the contents of two pigments (chlorophyll and carotenoid) for both species decreased under high temperature; however, heat-tolerant A. scabra exhibited delayed and less severe decline in all parameters compared with heat-sensitive A. stolonifera. Ethylene production rate increased in both species at 35 °C, but the increase was observed 21 days later in A. scabra compared with that in A. stolonifera. ABA content increased at the initiation of heat stress and then declined in both species after prolonged heat stress. However, the timing of the increase was delayed for 7 days and the highest level of ABA content was less in A. scabra (4.0 times that of the control) than that in A. stolonifera (5.9 times that of the control). Decreases in both forms of cytokinins (transzeatin/zeatin riboside and isopentenyl adenosine) were also delayed for 14 days and less pronounced in A. scabra. Correlation analysis revealed that leaf senescence induced by heat stress was negatively correlated to ethylene and ABA accumulation and positively correlated to cytokinin production. Delayed leaf senescence in A. scabra under heat stress could be related to slower and less magnitude of changes in ethylene, ABA, and cytokinins.

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