scholarly journals Effect of long anther dehiscence on seed set at high temperatures during flowering in rice (Oryza sativa L.)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tsutomu Matsui ◽  
Toshihiro Hasegawa
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
High Temperatures ◽  
Seed Set ◽  
Oryza Sativa L ◽  
Quantitative Information ◽  
Temperature Tolerance ◽  
Anther Dehiscence ◽  
Substitution Lines ◽  
Global Warming Impact

AbstractCountermeasures that can mitigate the global warming impact on rice production are needed. The large dehiscence of anther for pollen dispersal is one trait that shows tolerance of seed set to high temperatures under the global warming. The aim of this study is to determine the effect of long anther dehiscence on high temperature tolerance. Seven chromosome segment substitution lines and the seed parent with the different dehiscence lengths were subjected to high daytime temperatures. Elongation of dehiscence formed at the base of anther (BDL) by 100 µm mitigated the occurrence of high temperature induced sterility by 20% and improved tolerance to the high temperature by 0.66 °C. Relationship between the seed set and BDL was well explained by pollination, showing that quantitative information provided in the present experiment is reliable. The information is expected to be used in estimation of global warming impact and making countermeasures for it.

Spikelet fertility and heat shock transcription factor (Hsf) gene responses to heat stress in tolerant and susceptible rice (Oryza sativa L.) genotypes

2019 ◽  
Vol 157 (04) ◽  
pp. 283-299 ◽  
Author(s):  
C. Malumpong ◽  
S. Cheabu ◽  
C. Mongkolsiriwatana ◽  
W. Detpittayanan ◽  
A. Vanavichit
Keyword(s):  
Heat Stress ◽  
Pollen Germination ◽  
Seed Set ◽  
Oryza Sativa L ◽  
Flag Leaf ◽  
Pollen Viability ◽  
Spikelet Fertility ◽  
Anther Dehiscence ◽  
Spikelet Sterility ◽  
Plant Parts

AbstractThe reproductive stage of rice is the most sensitive to heat stress, which can lead to spikelet sterility. Thus, heat-tolerant and heat-susceptible genotypes were used to investigate their differences in terms of phenotypic responses and expression changes of Hsf genes at the pre-flowering stage under heat stress. Results clearly showed that panicles had the highest temperature compared with other plant parts under both natural and heated conditions. However, the temperatures of tolerant and susceptible genotypes were not significantly different. In terms of spikelet fertility, the tolerant lines M9962 and M7988 had high seed set because their anther dehiscence, pollen viability and pollen germination were only slightly affected. In contrast, the susceptible line Sinlek showed severe effects at all steps of fertilization, and the pollen viability of M7766 was slightly affected under heat stress but was more affected in terms of anther dehiscence and pollen germination. Both susceptible lines showed dramatically decreased seed set. In addition, the expression of six HsfA genes in the flag leaves and spikelets at the R2 stage of plants under heat stress showed different responses. Notably, expression of the HsfA2a gene was predominantly upregulated in the flag leaf and spikelets under heat stress in M9962. Therefore, it can be concluded that heat stress has severe effects on the stamen, and that different genotypes have different susceptibilities to heat stress.

scholarly journals Treatments of Magnesium Slag to Recycle Waste from Pidgeon Process

2011 ◽  
Vol 418-420 ◽  
pp. 1657-1667 ◽  
Author(s):  
Feng Lan Han ◽  
Qi Xing Yang ◽  
Lan Er Wu ◽  
Sheng Wei Guo
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Natural Resources ◽  
Building Materials ◽  
Volume Stability ◽  
Global Warming Impact ◽  
Slag Powder ◽  
Magnesium Production ◽  
Higher Temperature ◽  
Pidgeon Process

Magnesium slag powder from a local magnesium plant was treated to improve the volume stability for its application as building materials. The slag was mixed with borates, pressed into briquettes, and then sintered at high temperature. SEM studies show that at the higher temperature Ca2SiO4polymorphs were stabilized by Na and B ions in the added borates. The free MgO content in the slag was also decreased by the sintering treatment. The slag powder, after mixing with 0.4-0.6% of borates and sintered at 1200°C in 5-6 hours, has become volume stable aggregates. It is then possible to use the treated slag in constructions, saving valuable natural resources and decreasing the global warming impact from magnesium production via Pidgeon process.

scholarly journals Evaluation of mutant rice genotypes for tolerance to high temperature

2021 ◽  
pp. 44-50
Author(s):  
María Caridad González Cepero ◽  
Elizabeth Cristo ◽  
Noraida Pérez ◽  
Yanelis Reyes ◽  
Dayné Horta ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
High Temperature ◽  
Cell Membrane ◽  
High Temperatures ◽  
Oryza Sativa L ◽  
Pollen Viability ◽  
Water Supplies ◽  
Rice Genotypes ◽  
Mutant Lines

Rice (Oryza sativa L.) is planted in about a tenth of the arable area around the world and is the largest source of food energy for half of humanity. Climatic change with increasing frequency of severe and prolonged drought periods and significant increases in air temperature has affected global rice production. Therefore, generating mutant rice cultivars tolerant to high temperatures and low water supplies is of utmost importance. Advanced mutant rice lines which were derived from irradiated Amistad -82 and J-104 were evaluated in the field under high temperatures and low water supply conditions using Amistad-82 variety as control. The genotypes with the best and worst field performances were compared using physiological parameters such as cell membrane thermostability, pollen viability, lipid peroxidation, and peroxidase and catalase activity under high temperature conditions. Three mutant lines, 8852, 8552 and LP-12 showed high yielding under high temperatures and low water supplies conditions in the field and also showed better pollen viability, cell membrane thermo stability, lipid peroxidation and peroxidase than LP-16 mutant lines and the control cv. Amistad-82. These results show that the physical irradiation of seeds with protons followed by subsequent in vitro embryo culture using 2,4D may generate genetic variability for tolerance to high temperatures. The variation observed for the physiological and biochemical indicators evaluated could be used for the early selection of high temperature tolerant rice genotypes

scholarly journals Lethal Effects of High Temperatures on Brown Marmorated Stink Bug Adults before and after Overwintering

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 355 ◽  
Author(s):  
Davide Scaccini ◽  
Carlo Duso ◽  
Alberto Pozzebon
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Cost Effective ◽  
Temperature Tolerance ◽  
Brown Marmorated Stink Bug ◽  
Stink Bug ◽  
Response Curves ◽  
High Temperature Tolerance ◽  
Before And After ◽  
Temperature Exposure

The invasive brown marmorated stink bug, Halyomorpha halys, is causing economic and ecological damage in invaded areas. Its overwintering behavior warrants mitigation practices in warehouses and shipping operations. The aim of this study was to characterize the mortality response curves of H. halys adults to short high-temperature exposure. Here we compared field-collected individuals entering (ENA) and exiting diapause (EXA). EXA adults displayed increased susceptibility to high temperatures compared to ENA individuals. Complete mortality of all tested individuals was obtained after 10 min exposure at 50.0 °C, and after 15 (EXA) or 20 min (ENA) at 47.5 °C. The nutritional status of these insects had no effect on high-temperature tolerance. The mortality curves obtained here may be used for the definition of cost-effective heat treatments aimed at the H. halys control.

scholarly journals Involvement of Ca2+ in Regulation of Physiological Indices and Heat Shock Factor Expression in Four Iris germanica Cultivars under High-temperature Stress

2014 ◽  
Vol 139 (6) ◽  
pp. 687-698 ◽  
Author(s):  
Jing Mao ◽  
Hongliang Xu ◽  
Caixia Guo ◽  
Jun Tong ◽  
Yanfang Dong ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Shock ◽  
Temperature Stress ◽  
High Temperatures ◽  
Soluble Protein ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Heat Shock Factor ◽  
High Temperature Tolerance ◽  
Iris Germanica

Although tolerance to high temperature is crucial to the summer survival of Iris germanica cultivars in subtropical areas, few physiological studies have been conducted on this topic previously. To remedy this, this study explored the physiological response and expression of heat shock factor in four I. germanica cultivars with varying levels of thermotolerance. The plants’ respective degrees of high-temperature tolerance were evaluated by measuring the ratio and area of withered leaves under stress. Several physiological responses to high temperatures were investigated, including effects on chlorophyll, antioxidant enzymes, proline, and soluble protein content in the leaves of four cultivars. CaCl2 was sprayed on ‘Gold Boy’ and ‘Royal Crusades’ considered being sensitive to high temperatures to study if Ca2+ could improve the tolerance, and LaCl3 was sprayed on ‘Music Box’ and ‘Galamadrid’ with better high-temperature tolerance to test if calcium ion blocker could decrease their tolerance. Heat shock factor genes were partially cloned according to the conserved region sequence, and expression changes to high-temperature stress with CaCl2 or LaCl3 treatments were thoroughly analyzed. Results showed that high temperature is the primary reason for large areas of leaf withering. The ratio and area of withered leaves on ‘Music Box’ and ‘Galamadrid’ were smaller than ‘Gold Boy’ and ‘Royal Crusades’. CaCl2 slowed the degradation of chlorophyll content and increased proline and soluble protein in ‘Gold Boy’ and ‘Royal Crusades’ but had no significant effect on activating peroxidase or superoxide to improve high-temperature tolerance. Genetic expression of heat shock factor in ‘Gold Boy’ and ‘Royal Crusades’ was upregulated by Ca2+ at later stages of leaf damage under high-temperature stress. LaCl3 down-regulated the physiological parameters and expression level of heat shock factor in ‘Music Box’ and ‘Galamadrid’. These results suggest that different I. germanica cultivars have varying high-temperature tolerance and furthermore that Ca2+ regulates their physiological indicators and expression level of heat shock factor under stress.

scholarly journals Identification of Thermotolerant Rice Genotypes with Allele Coding at Seedling Stage

2021 ◽  
Author(s):  
Bandi Arpitha Shankar ◽  
Prashant Kaushik
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Heat Tolerance ◽  
Temperature Tolerance ◽  
High Survival ◽  
Breeding Programs ◽  
Survival Percentage ◽  
High Temperature Tolerance ◽  
Rice Genotypes ◽  
Heat Tolerant

AbstractRice-The most important plant in the world to ensure food security. Heat is one of the main factors that greatly limit rice production. With the increasing global warming, industrialization there is a great effect on climate change which requires us to see various alternatives for strains that are more tolerant to heat so that some techniques are developed to filter a large number of genotypes for high temperature tolerance. Here we report the standardization of Temperature Induction Response (TIR) technique to identify thermotolerant rice genotypes. The phenotypic characteristics of Rice due to high temperature is calculated with germination (%), growth of the seedling and molecular analysis is also considered. The heat stress is provided to the plants with the help of TIR protocol with the adjustment of temperature to lethal (55°C) and sub-lethal levels (38-55°C) in a TIR chamber with alterations in humidity. Of the 74 genotypes screened, 14 showed thermo tolerance caused by high temperatures. Both tolerant and sensitive genotypes were separated based on their survival percentages. The tolerant class are selected based on the growth and development of genotypes having high survival percentage and also their shoot and root lengths, fresh and dry weights are compared to the heat tolerant checks N22, Dular and Nipponbare. These genotypes have intrinsic heat tolerance and thus can be explored as a source of donors in breeding programs intended for global warming. The molecular markers which are identified to be linked with heat tolerant class through allele code are quite helpful and can be used in marker assisted breeding approach to attain heat tolerance in cultivated varieties.

scholarly journals High temperature tolerance in chickpea and its implications for plant improvement

2012 ◽  
Vol 63 (5) ◽  
pp. 419 ◽  
Author(s):  
V. Devasirvatham ◽  
D. K. Y. Tan ◽  
P. M. Gaur ◽  
T. N. Raju ◽  
R. M. Trethowan
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
High Temperatures ◽  
Floral Organ ◽  
Temperature Tolerance ◽  
Male And Female ◽  
High Temperature Tolerance ◽  
The Status ◽  
Significant Yield ◽  
The Impact

Chickpea (Cicer arietinum L.) is an important food legume and heat stress affects chickpea ontogeny over a range of environments. Generally, chickpea adapts to high temperatures through an escape mechanism. However, heat stress during reproductive development can cause significant yield loss. The most important effects on the reproductive phase that affect pod set, seed set and yield are: (1) flowering time, (2) asynchrony of male and female floral organ development, and (3) impairment of male and female floral organs. While this review emphasises the importance of high temperatures >30°C, the temperature range of 32–35°C during flowering also produces distinct effects on grain yield. Recent field screening at ICRISAT have identified several heat-tolerant germplasm, which can be used in breeding programs for improving heat tolerance in chickpea. Research on the impact of heat stress in chickpea is not extensive. This review describes the status of chickpea production, the effects of high temperature on chickpea, and the opportunities for genetic improvement of chickpea tolerance to high temperatures.

Temperature Tolerance and Acclimatization in Drosophila Subobscura

1957 ◽  
Vol 34 (1) ◽  
pp. 85-96 ◽  
Author(s):  
J. MAYNARD SMITH
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Adult Life ◽  
Complete Recovery ◽  
Temperature Tolerance ◽  
Drosophila Subobscura ◽  
Survival Times ◽  
Dry Air ◽  
Different Temperatures ◽  
The Times

1. The times for which adult Drosophila subobscura survived at high temperatures in dry and in saturated air were measured at different temperatures, over a range of survival times from 20 to 400 min. There is a linear relationship between the logarithm of the survival time and the temperature in both cases, the values of Q10 being approximately 350 in dry air and 10,000 in wet air. 2. Survival times in dry air were increased in individuals previously kept at a high temperature (25°C.). Two kinds of acclimatization can take place, a longlasting ‘developmental acclimatization’ in individuals kept at 25°C. during pre-adult life, and a transitory ‘physiological acclimatization’ in adults kept at 25°C. 3. Survival times in saturated air were only slightly increased in individuals previously kept at 25°C. 4. Although physiological acclimatization increased the resistance of flies to desiccation rather than to high temperature as such, it is nevertheless a response to previous exposure to high temperatures, and not to high saturation deficiencies. 5. The reversibility of changes occurring at high temperatures was studied by exposing individuals for 50 min. to a temperature which would kill them in 100 min. and then retesting them after an intervening period at 20°C. Flies exposed to dry air recovered fully if they were allowed to drink; flies exposed to saturated air recovered in 3 hr. at 20°C., but complete recovery in this period required the presence of food and water.

scholarly journals High-temperature Tolerance of Heritage River Birch Roots Decreased by Pot-In-Pot Production Systems

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 813-814 ◽  
Author(s):  
John M. Ruter
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Electrolyte Leakage ◽  
Production Systems ◽  
Root Zone ◽  
Root Systems ◽  
Temperature Tolerance ◽  
High Temperature Tolerance ◽  
Aboveground Production ◽  
Membrane Thermostability

Membrane thermostability of Heritage river birch (Betula nigra L. Heritage) was measured by electrolyte leakage from excised roots of plants grown in pot-in-pot (PIP) and conventional aboveground production systems (CPS). The predicted critical midpoint temperature (Tm) for a 30-min exposure was 54.6 ± 0.2 °C for PIP and 56.2 ± 0.6 °C for CPS plants. Plants grown PIP had a steeper slope through the predicted Tm, suggesting a decreased tolerance to high root-zone temperatures in relation to plants grown aboveground. Since the root systems of Heritage river birch grown PIP are damaged at lower temperatures than plants grown aboveground, growers should prevent exposure of root systems to high temperatures during postproduction handling of plants grown PIP.

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