scholarly journals Identification of stress indices for screening of rice cultivars under high temperature

2021 ◽  
Vol 17 (AAEBSSD) ◽  
pp. 266-272
Author(s):  
N. Veronica ◽  
T. Sujatha ◽  
P.V. Ramana Rao
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Geometric Mean ◽  
High Temperature Stress ◽  
Stress Conditions ◽  
Abiotic And Biotic Stresses ◽  
Biotic Stresses ◽  
Calculated Stress ◽  
Selection Indices ◽  
Stress Susceptibility

Rice is an important cereal crop and its productivity is being affected by many abiotic and biotic stresses. High temperature affects the rice yield and productivity. Thirty rice genotypes were evaluated in normal and under high temperature stress conditions. There was reduction in grain yield in all the tested genotypes. Based on yield recorded under normal and high temperature conditions, yield based indices were calculated. Stress Susceptibility Index (SSI), Geometric Mean Production (GMP), Mean Production (MP), Yield Index (YI), Modified stress tolerance (K1STI and K2STI) were significantly and positively correlated to yield under both stress and non-stress conditions and could be considered as good selection indices for screening for heat tolerance. Genotypes were ranked based on their tolerant or susceptibility indices and it was noted that among all IET 28412, IET 28397 and IET 28432 exhibited highest mean rank and a lower standard deviation of rank, hence they can be identified as heat tolerant genotypes. Genotypes IET 26468, IET 28393 and Gontrabidhan-3 were identified as highly susceptible to high temperature stress.

scholarly journals Evaluation of stress indices for screening of rice cultivars for high temperature tolerance

2019 ◽  
Vol 56 (4) ◽  
pp. 341-351
Author(s):  
Veronica N ◽  
Ashoka Rani Y ◽  
Subrahmanyam D ◽  
Narasimha Rao KL ◽  
Lal Ahamad M ◽  
...  
Keyword(s):  
High Temperature ◽  
Grain Yield ◽  
Temperature Stress ◽  
Geometric Mean ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Growing Period ◽  
High Temperature Tolerance ◽  
Severe Reduction ◽  
Stress Susceptibility

High temperature during the crop growing period is detrimental as it results in reduction of yield. A diverse set of rice germplasm consisting of 60 genotypes was grown at two different sowing times (normal and late) and were exposed naturally to high temperature in the late sown condition (stress). There was a severe reduction in grain yield and spikelet fertility in all the genotypes in the late sown crop. Yield based indices were computed based on grain yield recorded under normal and stress conditions. Indices Stress Susceptibility Index (STI), Geometric Mean Production (GMP), Mean Production (MP), Yield Index (YI), Modified stress tolerance (K1STI and K2STI) were positively correlated with yield recorded under both normal and high temperature stress condition and can be considered as suitable indices for screening of rice genotypes under high temperature conditions. Ranking genotypes based on the indices revealed that Rasi, HKR47, IR64, Khudaridhan, Akshayadhan and N22 exhibited the highest mean rank and hence they can be identified as heat-tolerant genotypes. ADT43, Vandana, IR36, MTU1001, ADT49 and Krishnahamsa had a lower rank and were identified as susceptible genotypes to high-temperature stress.

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 < 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.

TIR approach and stress tolerance indices to identify donor for high-temperature stress tolerance in pepper (Capsicum annuum L.)

2020 ◽  
Vol 18 (1) ◽  
pp. 19-27
Author(s):  
Smaranika Mishra ◽  
R. H. Laxman ◽  
K. Madhavi Reddy ◽  
R. Venugopalan
Keyword(s):  
High Temperature ◽  
Stress Tolerance ◽  
Capsicum Annuum ◽  
Temperature Stress ◽  
Geometric Mean ◽  
Stability Index ◽  
High Temperature Stress ◽  
Bell Pepper ◽  
Tolerance Index ◽  
Tolerance Indices

AbstractBell pepper or sweet pepper (Capsicum annuum L. var. grossum) is highly susceptible to high-temperature stress (HT). Hence, search for donor across C. annuum for HT tolerance was undertaken by following Temperature Induction Response (TIR) technique. The induction and challenging temperature requirement for TIR screening were standardized in 1 d-old Capsicum seedlings. Forty Capsicum genotypes were evaluated based on the recovery growth (RG) and per cent reduction in recovery growth (%RRG) of the seedlings. The genotypes Punjab Guchhedar and Ajeet 1 were found to have maximum cellular level tolerance (CLT) to HT with higher RG and lower %RRG compared to the non-induced seedlings and HDC 75 was found to have minimum CLT. In order to confirm the findings, another experiment was conducted under managed stress and control conditions. Absolute yield obtained from both the environments were used to calculate stress tolerance indices such as heat susceptibility index, tolerance index, stress tolerance index, mean productivity, geometric mean productivity and yield stability index. Based on these tolerance indices, Punjab Guchhedar and Ajeet 1 were found to be highly tolerant and HDC 75 as highly susceptible. Further, the combined result of TIR and tolerance indices also gave the same result confirming Punjab Guchhedar and Ajeet 1 can be used as a donor for the future breeding programme aimed at evolving high-temperature-tolerant bell pepper cultivars. The result also confirms the fitness of TIR technique to screen Capsicum genotypes for tolerance to HT based on variability in acquired thermotolerance.

scholarly journals Unraveling Heat Tolerance in Upland Cotton (Gossypium hirsutum L.) Using Univariate and Multivariate Analysis

2022 ◽  
Vol 12 ◽  
Author(s):  
Muhammad Mubashar Zafar ◽  
Xue Jia ◽  
Amir Shakeel ◽  
Zareen Sarfraz ◽  
Abdul Manan ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Fiber Quality ◽  
High Temperature Stress ◽  
Stress Conditions ◽  
Cotton Yield ◽  
Mean Values ◽  
White Gold

The ever-changing global environment currently includes an increasing ambient temperature that can be a devastating stress for organisms. Plants, being sessile, are adversely affected by heat stress in their physiology, development, growth, and ultimately yield. Since little is known about the response of biochemical traits to high-temperature ambiance, we evaluated eight parental lines (five lines and three testers) and their 15 F1 hybrids under normal and high-temperature stress to assess the impact of these conditions over 2 consecutive years. The research was performed under a triplicate randomized complete block design including a split-plot arrangement. Data were recorded for agronomic, biochemical, and fiber quality traits. Mean values of agronomic traits were significantly reduced under heat stress conditions, while hydrogen peroxide, peroxidase, total soluble protein, superoxide dismutase, catalase (CAT), carotenoids, and fiber strength displayed higher mean values under heat stress conditions. Under both conditions, high genetic advance and high heritability were observed for seed cotton yield (SCY), CAT, micronaire value, plant height, and chlorophyll-a and b content, indicating that an additive type of gene action controls these traits under both the conditions. For more insights into variation, Pearson correlation analysis and principal component analysis (PCA) were performed. Significant positive associations were observed among agronomic, biochemical, and fiber quality-related traits. The multivariate analyses involving hierarchical clustering and PCA classified the 23 experimental genotypes into four groups under normal and high-temperature stress conditions. Under both conditions, the F1 hybrid genotype FB-SHAHEEN × JSQ WHITE GOLD followed by Ghuari-1, CCRI-24, Eagle-2 × FB-Falcon, Ghuari-1 × JSQ White Gold, and Eagle-2 exhibited better performance in response to high-temperature stress regarding the agronomic and fiber quality-related traits. The mentioned genotypes could be utilized in future cotton breeding programs to enhance heat tolerance and improve cotton yield and productivity through resistance to environmental stressors.

scholarly journals Adaptation of Interspecific Mesoamerican Common Bean Lines to Acid Soils and High Temperature in the Amazon Region of Colombia

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2412
Author(s):  
Juan Carlos Suárez ◽  
Milan O. Urban ◽  
Amara Tatiana Contreras ◽  
Miguel Ángel Grajales ◽  
Cesar Cajiao ◽  
...  
Keyword(s):  
High Temperature ◽  
Common Bean ◽  
Temperature Stress ◽  
Energy Use ◽  
Acid Soil ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Amazon Region ◽  
Stress Conditions ◽  
Photosynthate Partitioning

Knowledge of the physiological basis for improved genetic adaptation of common bean (Phaseolus vulgaris L.) lines to acid soils and high temperature conditions in the Amazon region of Colombia is limited. In this study, we evaluated the differences among 41 common bean lines in energy use, leaf cooling, photosynthate partitioning to pod formation and grain filling, and grain yield over two seasons under acid soil and high temperature stress in the Amazon region of Colombia. Common bean lines evaluated included medium and large seeded interspecific lines of Mesoamerican and Andean gene pools with different levels of adaptation to abiotic stress conditions and some lines are improved for iron and zinc (biofortified) concentration in seeds. We found three bean lines (GGR 147, SMG 21 and SMG 12) that were superior in their photosynthetic response, leaf cooling, photosynthate partitioning ability to pod formation and grain filling, resulting in grain yields exceeding 1900 kg ha−1 under acid soil and high temperature stress conditions. The superior photosynthetic performance was attributed to the efficient use of absorbed energy on the electron level in thylakoids, which is mainly oriented to a higher quantum yield of PSII (ΦII), lower energy dissipation in the form of heat (ΦNPQ), high linear electron flow (LEF) and high fraction of PSI centers in open state (PSIopen). We speculate that these photosynthetic and photosynthate partitioning responses of superior bean lines are part of the genetic adaptation to acidic soils and high temperature stress conditions. Among the evaluated bean lines, three lines (GGR 147, SMG 21 and SMG 12) combined the desirable attributes for genetic improvement of stress tolerance and biofortification. These lines can serve as parents to further improve traits (energy use efficiency and multiple stress resistance) that are important for bean production in the Amazon region.

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