Genetic Variation for Heat Tolerance in Primitive Cultivated Subspecies ofTriticum turgidumL.

2015 ◽  
Vol 29 (5) ◽  
pp. 565-580 ◽  
Author(s):  
Jianming Fu ◽  
Robert L. Bowden ◽  
P. V. Vara Prasad ◽  
Amir M.H. Ibrahim
Keyword(s):  
Genetic Variation ◽  
Heat Tolerance

Correction to: Genetic diversity and genetic variation in morpho-physiological traits to improve heat tolerance in Spring barley

2018 ◽  
Vol 46 (2) ◽  
pp. 2597-2597
Author(s):  
Ahmed Sallam ◽  
Ahmed Amro ◽  
Ammar Elakhdar ◽  
Mona F. A. Dawood ◽  
Toshihiro Kumamaru ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Heat Tolerance ◽  
Spring Barley ◽  
Physiological Traits

Assessing genetic variation for heat stress tolerance in Indian bread wheat genotypes using morpho-physiological traits and molecular markers

2016 ◽  
Vol 15 (6) ◽  
pp. 539-547 ◽  
Author(s):  
P. Sharma ◽  
S. Sareen ◽  
M. Saini ◽  
Shefali
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Heat Stress ◽  
Molecular Markers ◽  
Heat Tolerance ◽  
Polymorphic Information Content ◽  
Physiological Traits ◽  
Phenotypic Traits ◽  
Phenotypic Data ◽  
Wheat Genotypes

AbstractHeat stress greatly limits the productivity of wheat in many regions. Knowledge on the degree of genetic diversity of wheat varieties along with their selective traits will facilitate the development of high yielding, stress-tolerant wheat cultivar. The objective of this study were to determine genetic variation in morpho-physiological traits associated with heat tolerance in 30 diverse wheat genotypes and to examine genetic diversity and relationship among the genotypes varying heat tolerance using molecular markers. Phenotypic data of 15 traits were evaluated for heat tolerance under non-stress and stress conditions for two consecutive years. A positive and significant correlation among cell membrane stability, canopy temperature depression, biomass, susceptibility index and grain yield was shown. Genetic diversity assessed by 41 polymorphic simple sequence repeat (SSR) markers was compared with diversity evaluated for 15 phenotypic traits averaged over stress and non-stress field conditions. The mean polymorphic information content for SSR value was 0.38 with range of 0.12–0.75. Based on morpho-physiological traits and genotypic data, three groups were obtained based on their tolerance (HHT, MHT and LHT) levels. Analysis of molecular variance explained 91.7% of the total variation could be due to variance within the heat tolerance genotypes. Genetic diversity among HHT was higher than LHT genotypes and HHT genotypes were distributed among all cluster implied that genetic basis of heat tolerance in these genotypes was different thereby enabling the wheat breeders to combine these diverse sources of genetic variation to improve heat tolerance in wheat breeding programme.

Genetic Variation for Heat Tolerance During the Reproductive Phase in Brassica rapa

2013 ◽  
Vol 199 (6) ◽  
pp. 424-435 ◽  
Author(s):  
Annisa ◽  
S. Chen ◽  
N. C. Turner ◽  
W. A. Cowling
Keyword(s):  
Genetic Variation ◽  
Brassica Rapa ◽  
Heat Tolerance ◽  
Reproductive Phase

scholarly journals Genomic and transcriptomic signals of thermal tolerance in heat-tolerant corals (Platygyra daedalea) of the Arabian/Persian Gulf

2017 ◽  
Author(s):  
Nathan L. Kirk ◽  
Emily J. Howells ◽  
David Abrego ◽  
John A. Burt ◽  
Eli Meyer
Keyword(s):  
Genetic Variation ◽  
Heat Tolerance ◽  
Stress Responses ◽  
Thermal Tolerance ◽  
Large Fraction ◽  
Coral Host ◽  
Adaptive Responses ◽  
Transcriptional Responses ◽  
Functional Basis ◽  
Heat Tolerant

AbstractScleractinian corals occur in tropical regions near their upper thermal limits, and are severely threatened by rising ocean temperatures. Ocean warming leads to loss of symbiotic algae (Symbiodinium), reduced fitness for the coral host, and degradation of the reef. However, several recent studies have shown that natural populations of corals harbor genetic variation in thermal tolerance that may support adaptive responses to warming. Here we’ve extended these approaches to study heat tolerance of corals in the Persian/Arabian Gulf, where heat-tolerant local populations have adapted to warm summer temperatures (>36°C). To evaluate whether selection has depleted genetic variation in thermal tolerance, estimate the potential for future adaptive responses, and understand the functional basis for these corals’ unusual heat tolerance, we measured thermal tolerance using controlled crosses in the Gulf coral Platygyra daedalea. We found that heat tolerance is highly heritable in this population (0.487-0.748), suggesting substantial potential for adaptive responses to selection for thermal tolerance. To identify genetic markers associated with this variation, we conducted genomewide SNP genotyping in parental corals and tested for relationships between paternal genotype and thermal tolerance of the offspring. We found that multilocus SNP genotypes explained a large fraction of variation in thermal tolerance in these crosses (69%). To investigate the functional basis of these differences in thermal tolerance, we profiled transcriptional responses in tolerant and susceptible families, revealing substantial sire effects on transcriptional responses to thermal stress. We also studied sequence variation in these expressed sequences, identifying alleles and functional groups associated with thermal tolerance. Our findings demonstrate that corals in these populations harbor extensive genetic variation in thermal tolerance, and these heat-tolerant phenotypes differ in both gene sequences and transcriptional stress responses from their susceptible counterparts.

scholarly journals Genetic variation in heat tolerance of the coral Platygyra daedalea offers the potential for adaptation to ocean warming

2020 ◽  
Author(s):  
Holland Elder ◽  
Virginia Weis ◽  
Jose Montalvo-Proano ◽  
Veronique J.L Mocellin ◽  
Andrew H. Baird ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Nucleotide Polymorphisms ◽  
Narrow Sense Heritability ◽  
Coding Regions ◽  
Genomic Tools ◽  
Coral Reef Ecosystems ◽  
Few Data ◽  
Genomic Regions

AbstractReef-building corals are foundational species in coral reef ecosystems and are threatened by many stressors including rising ocean temperatures. In 2015/16 and 2016/17, corals around the world experienced consecutive bleaching events and most coral populations are projected to experience temperatures above their current bleaching thresholds annually by 2050. Adaptation to higher temperatures is therefore necessary if corals are to persist in a warming future. While many aspects of heat stress have been well studied, few data are available for predicting the capacity for adaptive cross-generational responses in corals. To address this knowledge gap, we quantified the heritability and genetic variation associated with heat tolerance in Platygyra daedalea from the Great Barrier Reef (GBR). We tracked the survival of replicate quantitative genetic crosses (or families) of coral larvae from six parents in a heat stress selection experiment. We also identified allelic shifts in heat-selected survivors versus paired, non-selected controls of the same coral crosses. We estimated narrow sense heritability to be 0.66 and detected a total of 1,069 single nucleotide polymorphisms (SNPs) associated with heat tolerance. An overlap of 148 unique SNPs shared between experimental crosses indicates that specific genomic regions are responsible for heat tolerance of P. daedalea and some of these SNPs fall in coding regions. These findings suggest that this P. daedalea population has the genetic prerequisites for adaptation to increasing temperatures. This study also provides knowledge for the development of high throughput genomic tools to screen for variation within and across populations to harness or enhance adaptation through assisted gene flow and assisted migration.

scholarly journals The wheat Seven in Absentia gene is associated with increases in biomass and yield in hot climates

2019 ◽  
Author(s):  
Pauline Thomelin ◽  
Julien Bonneau ◽  
Chris Brien ◽  
Radoslaw Suchecki ◽  
Ute Baumann ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Positional Cloning ◽  
Genomic Region ◽  
Sequence Variant ◽  
Positive Allele ◽  
Breeding Programmes ◽  
Seven In Absentia

AbstractWheat productivity is severely reduced by high temperatures. Breeding of heat tolerant cultivars can be achieved by identifying genes controlling physiological and agronomical traits with high temperature and using these to select superior genotypes, but no gene underlying genetic variation for heat tolerance has previously been described. We completed the positional cloning of qYDH.3BL, a quantitative trait locus (QTL) on bread wheat chromosome 3B associated with increased yield in hot and dry climates. The delimited genomic region contained 12 putative genes and a sequence variant in the promoter region of one gene - seven in absentia, TaSINA. This was associated with the QTL’s effects on early vigour, plant biomass and yield components in two distinct wheat populations grown under various growth conditions. Near isogenic lines carrying the positive allele at qYDH.3BL under-expressed TaSINA and had increased vigour and water use efficiency early in development, as well as increased biomass, grain number and grain weight following heat stress. A survey of worldwide distribution indicated that the positive allele became widespread from the 1950s through the CIMMYT wheat breeding programme but, to date, has been selected only in breeding programmes in Mexico and Australia.Significance statementWheat is the world’s most widely grown crop and a staple of human diet. Even brief episodes of high temperature in the growing season cause severe yield reductions. Finding and deploying genes for heat stress tolerance in new varieties is a priority for food security with climate change. We narrowed a genetic locus to a small genomic region where genetic variation was present only in one gene that showed clear differences of expression and improved yield and physiology under stress in the populations. Using diagnostic markers to track the positive haplotype in nearly 750 accessions, we found many regions where the allele could be used in breeding programmes to increase wheat’s heat tolerance.

scholarly journals Differential Responses of Amino Acids and Soluble Proteins to Heat Stress Associated with Genetic Variations in Heat Tolerance for Hard Fescue

2018 ◽  
Vol 143 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Jinyu Wang ◽  
Bo Yuan ◽  
Yi Xu ◽  
Bingru Huang
Keyword(s):  
Amino Acids ◽  
Genetic Variation ◽  
Heat Stress ◽  
Amino Acid ◽  
Heat Tolerance ◽  
Amino Acid Content ◽  
Soluble Proteins ◽  
Total Soluble Protein ◽  
Total Amino Acid ◽  
Amino Acid Synthesis

Amino acid and protein metabolism are interrelated and both play important roles in plant adaptation to heat stress. The objective of this study was to identify amino acids and soluble proteins associated with genetic variation in heat tolerance of hard fescue (Festuca trachyphylla). According to a previous screening experiment, the hard fescue cultivars Reliant IV and Predator were selected as heat-tolerant and heat-sensitive cultivars, respectively. Plants of these two hard fescue cultivars were exposed to heat stress at 38/33 °C (day/night) or optimal temperature at 21/18 °C in growth chambers. Each cultivar had four replications under each temperature, and the experimental design was a split-plot design, temperature as the main plots and cultivars as the subplots. Under heat stress, ‘Reliant IV’ exhibited higher turf quality (TQ) and greater membrane stability than ‘Predator’. In response to heat stress, total amino acid content increased, whereas total soluble protein content decreased in both cultivars. The greater accumulation of amino acids in ‘Reliant IV’ was contributed by the greater increase of proteins involved in the glycolysis and the tricarboxylic acid (TCA) cycle that provided carbon skeleton for amino acid synthesis. ‘Reliant IV’ leaves exhibited greater extent of increases in the content of six individual amino acids (histidine, glutamine, proline, threonine, aspartate, and tryptophan) than ‘Predator’ under heat stress. Several soluble proteins were upregulated in response to heat stress, to a greater extent in ‘Reliant IV’ than ‘Predator’, including the proteins involved in photosynthesis, protein folding, redox hemostasis, stress signaling, stress defense, cell organization, and metabolism. These differentially accumulated free amino acids and soluble proteins could be associated with the genetic variation in heat tolerance of hard fescue.

Heat stress effects on farrowing rate in sows: Genetic parameter estimation using within-line and crossbred models1

2012 ◽  
Vol 90 (7) ◽  
pp. 2109-2119 ◽  
Author(s):  
S. Bloemhof ◽  
A. Kause ◽  
E. F. Knol ◽  
J.A.M. Van Arendonk ◽  
I. Misztal
Keyword(s):  
Genetic Variation ◽  
Genetic Correlation ◽  
Heat Tolerance ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Random Regression ◽  
Production Traits ◽  
Selection For ◽  
Heritability Estimates ◽  
Farrowing Rate

Abstract The pork supply chain values steady and undisturbed piglet production. Fertilization and maintaining gestation in warm and hot climates is a challenge that can be potentially improved by selection. The objective of this study was to estimate 1) genetic variation for farrowing rate of sows in 2 dam lines and their reciprocal cross; 2) genetic variation for farrowing rate heat tolerance, which can be defined as the random regression slope of farrowing rate against increasing temperature at day of insemination, and the genetic correlation between farrowing rate and heat tolerance; 3) genetic correlation between farrowing rate in purebreds and crossbreds; and 4) genetic correlation between heat tolerance in purebreds and crossbreds. The estimates were based on 93,969 first insemination records per cycle from 24,456 sows inseminated between January 2003 and July 2008. These sows originated from a Dutch purebred Yorkshire dam line (D), an International purebred Large White dam line (ILW), and from their reciprocal crosses (RC) raised in Spain and Portugal. Within-line and crossbred models were used for variance component estimation. Heritability estimates for farrowing rate were 0.06, 0.07, and 0.02 using within-line models for D, ILW, and RC, respectively, and 0.07, 0.07, and 0.10 using the crossbred model, respectively. For farrowing rate, purebred-crossbred genetic correlations were 0.57 between D and RC and 0.50 between ILW and RC. When including heat tolerance in the within-line model, heritability estimates for farrowing rate were 0.05, 0.08, and 0.03 for D, ILW, and RC, respectively. Heritability for heat tolerance at 29.3°C was 0.04, 0.02, and 0.05 for D, ILW, and RC, respectively. Genetic correlations between farrowing rate and heat tolerance tended to be negative in crossbreds and ILW-line sows, implying selection for increased levels of production traits, such as growth and reproductive output, is likely to increase environmental sensitivity. This study shows that genetic selection for farrowing rate and heat tolerance is possible. However, when this selection is based solely on purebred information, the expected genetic progress on farrowing rate and heat tolerance in crossbreds (commercial animals) would be inconsequential.

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