scholarly journals Impact of High Temperature Stress on Morpho Physiological Traits and Yield of Rice (Oryza sativa L.) Genotypes

2021 ◽  
Vol 108 ◽  
pp. 1-4
Author(s):  
Maheswari P ◽  
◽  
Chandrasekhar C N ◽  
Jeyakumar P ◽  
Saraswathi R ◽  
...  

High temperature stress is a major environmental factor that affects crop growth, development and yield, it especially limits rice yield. Hence, an experiment was conducted to study the impact of high temperature on morpho-physiological parameters and yield of rice genotypes. Ten rice genotypes were used in this study viz., N22, ADT 36, ADT 37, ADT 43, ADT 45, CO 51, ASD 16, MDU 6, TPS 5 and Anna (R) 4. The study was carried out at OTC (Open Top Chamber) with the treatments of ambient, ambient +2O C and ambient +4O C. Stress was imposed from anthesis to early grain filling period. Observations on plant height, the number of tillers, leaf area, SPAD (Chlorophyll index) and chlorophyll stability index (CSI) were done after the stress imposement and grain yield was calculated after harvest. Results revealed that, the significant changes were observed in morpho-physiological traits and grain yield of rice genotypes among the treatments and with the genotypes. N22 (10% and 19%) and Anna (R) 4 (12% and 22%) recorded less reduction of grain yield in ambient +2O C and ambient +4O C compared with ambient, due to less reduction of total chlorophyll content, SPAD values, leaf area and increased plant height. These parameters resulted in higher biomass which indirectly contributed to higher grain yield in N22 and Anna (R) 4 under high temperature

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 95
Author(s):  
Noureddine El Haddad ◽  
Hasnae Choukri ◽  
Michel Edmond Ghanem ◽  
Abdelaziz Smouni ◽  
Rachid Mentag ◽  
...  

High temperature and water deficit are among the major limitations reducing lentil (Lens culinaris Medik.) yield in many growing regions. In addition, increasing atmospheric vapor pressure deficit (VPD) due to global warming causes a severe challenge by influencing the water balance of the plants, thus also affecting growth and yield. In the present study, we evaluated 20 lentil genotypes under field conditions and controlled environments with the following objectives: (i) to investigate the impact of temperature stress and combined temperature-drought stress on traits related to phenology, grain yield, nutritional quality, and canopy temperature under field conditions, and (ii) to examine the genotypic variability for limited transpiration (TRlim) trait in response to increased VPD under controlled conditions. The field experiment results revealed that high-temperature stress significantly affected all parameters compared to normal conditions. The protein content ranged from 23.4 to 31.9%, while the range of grain zinc and iron content varied from 33.1 to 64.4 and 62.3 to 99.3 mg kg−1, respectively, under normal conditions. The grain protein content, zinc and iron decreased significantly by 15, 14 and 15% under high-temperature stress, respectively. However, the impact was more severe under combined temperature-drought stress with a reduction of 53% in protein content, 18% in zinc and 20% in iron. Grain yield declined significantly by 43% in temperature stress and by 49% in the combined temperature-drought stress. The results from the controlled conditions showed a wide variation in TR among studied lentil genotypes. Nine genotypes displayed TRlim at 2.76 to 3.51 kPa, with the genotypes ILL 7833 and ILL 7835 exhibiting the lowest breakpoint. Genotypes with low breakpoints had the ability to conserve water, allowing it to be used at later stages for increased yield. Our results identified promising genotypes including ILL 7835, ILL 7814 and ILL 4605 (Bakria) that could be of great interest in breeding for high yields, protein and micronutrient contents under high-temperature and drought stress. In addition, it was found that the TRlim trait has the potential to select for increased lentil yields under field water-deficit environments.


2017 ◽  
Vol 9 (4) ◽  
pp. 2410-2413
Author(s):  
Kamla Dhyani ◽  
Alok Shukla ◽  
R.S. Verma

High temperature stress during grain-filling period is one of the major environmental constraints limiting the grain yield of wheat in India. Crop growth response and relative performance of yield components of 12 wheat (Triticum aestivum) genotypes were studied in two date of sowing in crop research center (Pantnagar) to identify the causes of yield reduction in wheat particularly Leaf Area Index and its impact in yield loss and other tolerance mech-anism and comparative study of LAI and yield attributes to identify the genotype for high temperature tolerance in late sown condition. The higher temperature enhanced plant growth, flowering, and maturation which ultimately effects the crop performance in case of yield (Leaf Area Index, grain weight/spike and test weight were drastically reduced in time under high temperature. Out of 12 diverse genotypes namely HI 1539, DBW 14, HW 5021, HS 240, PBW-574, Raj 4101, Lok 54, Raj 3765, WH 1021, K-0-307, HW 2045 and HI1544,four were (Lok54, Raj3765, HI1539 and HI1544 ) were characterized as high temperature tolerant based on their relative performance in leaf area index, grain yield and heat susceptibility index. Leaf area Index studies in context to heat stress in wheat is least studied area in heat tolerance research in wheat (Triticum aestivum), in the present study LAI is used as a screening tool for heat tolerance and effect of LAI in wheat yield.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1099
Author(s):  
Hongyin Qi ◽  
Dingfan Kang ◽  
Weihang Zeng ◽  
Muhammad Jawad Hassan ◽  
Yan Peng ◽  
...  

Persistent high temperature decreases the yield and quality of crops, including many important herbs. White clover (Trifolium repens) is a perennial herb with high feeding and medicinal value, but is sensitive to temperatures above 30 °C. The present study was conducted to elucidate the impact of changes in endogenous γ-aminobutyric acid (GABA) level by exogenous GABA pretreatment on heat tolerance of white clover, associated with alterations in endogenous hormones, antioxidant metabolism, and aquaporin-related gene expression in root and leaf of white clover plants under high-temperature stress. Our results reveal that improvement in endogenous GABA level in leaf and root by GABA pretreatment could significantly alleviate the damage to white clover during high-temperature stress, as demonstrated by enhancements in cell membrane stability, photosynthetic capacity, and osmotic adjustment ability, as well as lower oxidative damage and chlorophyll loss. The GABA significantly enhanced gene expression and enzyme activities involved in antioxidant defense, including superoxide dismutase, catalase, peroxidase, and key enzymes of the ascorbic acid–glutathione cycle, thus reducing the accumulation of reactive oxygen species and the oxidative injury to membrane lipids and proteins. The GABA also increased endogenous indole-3-acetic acid content in roots and leaves and cytokinin content in leaves, associated with growth maintenance and reduced leaf senescence under heat stress. The GABA significantly upregulated the expression of PIP1-1 and PIP2-7 in leaves and the TIP2-1 expression in leaves and roots under high temperature, and also alleviated the heat-induced inhibition of PIP1-1, PIP2-2, TIP2-2, and NIP1-2 expression in roots, which could help to improve the water transportation and homeostasis from roots to leaves. In addition, the GABA-induced aquaporins expression and decline in endogenous abscisic acid level could improve the heat dissipation capacity through maintaining higher stomatal opening and transpiration in white clovers under high-temperature stress.


2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Rathnayake Mudiyanselage Nilusha Thushari Amarasinghe ◽  
Siti Zaharah Sakimin ◽  
Puteri Edaroyati Megat Wahab ◽  
ShairulIzan Ramlee ◽  
Juju Nakasha Jaafar

Rock melon is a high value greenhouse crop. Reduction of economical crop yield in high temperature stress due to global warming is an emerging issue with Rock melon. Therefore, this study was conducted for evaluate the growth, physiology and yield of different Rock melon cultivars grown under high temperature stress. Four cultivars of rock melon (Lady-gold, Lady-green, Himalai-99 and Glamour) were evaluated for their physiological behaviors under two temperature (42±3°C and 47 ±3°C) regimes. In four cultivars of rock melon, leaf area, specific leaf area, relative growth rate, chlorophyll content, photosynthesis rate, stomatal conductance, intercellular carbon dioxide concentration, transpiration rate, malondialdehyde content and fruit yield of Rock melon were significantly differ in each temperature regime. Temperature significantly affects the fruit position in main branch. When temperature increases, Rock melon fruits shifts in to upper branches. While Lady-green and Glamour shown similar attributes in extreme temperature, most susceptible cultivar was the Lady-gold and most tolerant cultivar was the Himalai-99.This study identified the issues of extreme temperature related to the economical yield of rock melon cultivars which can be use in future crop modification and breeding.


2020 ◽  
Vol 47 (5) ◽  
pp. 440 ◽  
Author(s):  
Syed Adeel Zafar ◽  
Amjad Hameed ◽  
Muhammad Ashraf ◽  
Abdus Salam Khan ◽  
Zia-ul- Qamar ◽  
...  

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 < 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.


2012 ◽  
Vol 49 (1) ◽  
pp. 53-73 ◽  
Author(s):  
SMRUTI DAS ◽  
P. KRISHNAN ◽  
MONALISA NAYAK ◽  
B. RAMAKRISHNAN

SUMMARYHigh temperature stress at flowering can adversely affect rice yield, largely due to failure of fertilization. Oxidative damage can be a major reason inducing spikelet sterility in rice. In the present study, the effect of high temperatures on antioxidant metabolism in rice spikelets was characterised using nine different genotypes. Exposure to different temperatures at flowering stage revealed significant differences among various antioxidant enzymes in spikelets, both quantitatively and qualitatively. Spikelets of susceptible genotypes withstood temperature stress of up to 35 °C, those of moderately tolerant between 35 °C and 38 °C and those of tolerant genotypes up to 40 °C. Presence or absence, and changes in the isozyme intensities were consistent with alterations in their activities. Superoxide dismutase (SOD) isozymes II and III were present after exposure at 30 °C and 35 °C, while SOD I appeared above 40°C. Intensities of catalase isozymes I and III and the only isozyme of ascorbate peroxidase altered, while the only isozyme of guaical peroxidase and two (III and IV) of the four isozymes of catechol peroxidase disappeared after high temperature exposure of 45 °C. Thus, this work provides an evidence of the role of antioxidant metabolism in spikelets under high temperature stress conditions. Hence, changes in antioxidant isozymes in rice spikelets can be used as a biomarker for characterizing high temperature stress tolerance in rice spikelets.


1970 ◽  
Vol 34 (3) ◽  
pp. 360-372 ◽  
Author(s):  
M Ataur Rahman ◽  
Jiro Chikushi ◽  
Satoshi Yoshida ◽  
AJMS Karim

High temperature stress during grain-filling period is one of the major environmental constraints limiting the grain yield of wheat in Bangladesh. Crop growth response and relative performance of yield components of ten wheat genotypes were studied in two temperature conditions in glass rooms in a Phytotron to identify the genotype tolerant to high temperature stress. A favourable day/night temperatures of 15/10, 20/15, and 25/20°C were maintained from sowing to 60 days after sowing (DAS), 61 to 80 DAS and 81 DAS to maturity, respectively, in one glass room (G1); whereas day/night temperatures in another glass room (G2) was always maintained at 5°C higher than that of G1. Green leaf area and number of tillers in different times, number of days for the occurrence of major crop growth stages, relative performance in yield components, grain yield and heat susceptibility index were estimated following the standard methods. The higher temperature enhanced plant growth, flowering, and maturation. Thus the number of days to booting, heading, anthesis, and maturity of wheat were significantly decreased that varied among the genotypes. Green leaf area and productive tillers/plant were drastically reduced in time under high temperature. The reduced number of grains/spike and smaller grain size resulted from drastic reduction in growth duration were responsible for the yield loss of wheat at high temperature. Out of ten wheat genotypes, three were characterized as high temperature tolerant based on their relative performance in yield components, grain yield and heat susceptibility index. Key Words: High-temperature tolerance, wheat genotype, growth and yield components. DOI: 10.3329/bjar.v34i3.3961 Bangladesh J. Agril. Res. 34(3) : 361-372, September 2009


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