scholarly journals Assessment of Rice Genotypes Response to Drought Stress at the early Reproductive Stage Using Stress Tolerance Indices

2018 ◽  
Vol 7 (4) ◽  
pp. 83-106
Author(s):  
Narjes Tabkhkar ◽  
Babak Rabiei ◽  
Habibollah Samizadeh Lahiji ◽  
Maryam Hosseini chaleshtori
Keyword(s):  
Drought Stress ◽  
Stress Tolerance ◽  
Reproductive Stage ◽  
Rice Genotypes ◽  
Tolerance Indices

scholarly journals Improvement of drought tolerance in rice using line X tester mating design and biochemical molecular markers

2022 ◽  
Vol 46 (1) ◽  
Author(s):  
Almoataz Bellah Ali El-Mouhamady ◽  
Abdul Aziz M. Gad ◽  
Ghada S. A. Abdel Karim
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Tolerance ◽  
Water Deficit ◽  
Scientific Progress ◽  
Crop Productivity ◽  
Hybrid Generation ◽  
Water Stress Tolerance ◽  
Rice Genotypes

Abstract Background Water stress, specifically the limited water resources needed to grow strategic crops, especially rice, poses a great threat to crop productivity. So, it was imperative that scientists all work together to try genetically improving the rice for drought tolerance in light of these environmental challenges. The aim of this study is trying to know the genetic behavior responsible for water-deficit tolerance in rice genotypes but at the molecular level. Moreover, this attempt will be an important leap in the process of genetic improvement in rice for water stress tolerance in Egypt. Results Twenty-three rice genotypes including eight parents and their fifteen F1 crosses or (the first hybrid generation) by line X tester analysis were evaluated for water stress tolerance during two experiments (the control and drought experiment) besides some molecular–biochemical studies for eight parents and the highest selected five crosses for water stress tolerance. The research revealed that five rice crosses out of fifteen hybrids were highly tolerant to water stress compared to the normal conditions. Data of biochemical markers indicated the presence of bands that are considered as molecular genetic markers for water-deficit tolerance in some rice genotypes, and this is the scientific progress achieved in this research. This was evident by increasing the density and concentration of SDS-protein electrophoresis besides enhancing the activities of peroxidase (POD) and polyphenol oxidase (PPO) under water-deficit conditions, which confirmed the tolerance of drought stress in the eight rice genotypes and the best five crosses from the first hybrid generation. Conclusion The five promising and superior rice hybrids showed an unparalleled tolerance to water stress in all evaluated traits under water stress treatment compared to the standard experiment. Also, biochemical and molecular parameters evidence confirmed the existence of unquestionable evidence that it represents the main nucleus for producing rice lines tolerated for drought stress under Egyptian conditions.

Physiological characterization of reproductive stage heat stress tolerance in contrasting rice genotypes

2020 ◽  
Vol 25 (1) ◽  
pp. 157-162
Author(s):  
Sourabh Karwa ◽  
Sunder Singh Arya ◽  
Sadhana Maurya ◽  
Madan Pal
Keyword(s):  
Heat Stress ◽  
Stress Tolerance ◽  
Reproductive Stage ◽  
Physiological Characterization ◽  
Heat Stress Tolerance ◽  
Rice Genotypes

scholarly journals Drought Stress Tolerance Screening of Elite American Breeding Rice Genotypes Using Low-Cost Pre-Fabricated Mini-Hoop Modules

Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 199 ◽  
Author(s):  
Ajaz A. Lone ◽  
Salah H. Jumaa ◽  
Chathurika Wijewardana ◽  
Shasthree Taduri ◽  
Edilberto D. Redona ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stress Tolerance ◽  
Seedling Establishment ◽  
Growth Parameters ◽  
Low Cost ◽  
Root Traits ◽  
Individual Response ◽  
Early Season ◽  
Drought Stress Tolerance ◽  
Rice Genotypes

Drought is a major abiotic stress factor affecting the growth and development of plants at all stages. Developing a screening tool for identifying drought stress tolerance during seedling establishment is important in the deployment of rice varieties suited to water-limited growing environments. An experiment was conducted to evaluate 100 rice genotypes, mostly belonging to the tropical japonica subspecies, for drought stress tolerance using low-cost, pre-fabricated mini-hoop structures. The rice seedlings were subjected to two different soil moisture regimes- control pots managed at 100% and drought pots at 50% field capacity, from 12 to 30 days after sowing (DAS). Several morpho-physiological parameters including root traits were measured to assess the response of genotypes to drought stress. Significant moisture stress × genotype interactions were found for most of the parameters measured. A cumulative drought stress response index (CDSRI) was developed by adding the individual response indices of all cultivars. Based on CDSRI and standard deviation values, 5 and 28 genotypes were identified as highly sensitive and sensitive to drought, respectively, and 45 as moderately sensitive. On the other hand, 16 and 6 genotypes were classified as tolerant and highly tolerant to drought, respectively. Cheniere, a released cultivar, and RU1402174, an experimental breeding line, were identified as the least and most tolerant to drought among the 100 genotypes tested. Significant linear correlation coefficients were obtained between CDSRI and root growth parameters (R2 = 0.91, n = 100) and CDSRI with shoot growth parameters (R2 = 0.48, n = 100), revealing the importance of root traits in studying and identifying drought tolerant lines during the seedling establishment stages in rice. The tolerant rice genotypes identified will be valuable for rice scientists in studying the mechanism for early season drought as well as for rice breeders for developing new genotypes best suited under growing environments prone to early-season drought.

scholarly journals Evaluation of a Hexaploid Wheat Collection (Triticum aestivum L.) under Drought Stress Conditions Using Stress Tolerance Indices

2020 ◽  
pp. 1-10
Author(s):  
Alireza Daneshvar Hosseini ◽  
Ali Dadkhodaie ◽  
Bahram Heidari ◽  
Seyed Abdolreza Kazemeini
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Geometric Mean ◽  
Triticum Aestivum L ◽  
Stress Conditions ◽  
Tolerance Index ◽  
Highly Correlated ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

Wheat is the most important crop in the world which faces the global problem of drought. Its production is affected by water deficit after pollination in arid and semi-arid regions. An experiment was conducted to assess tolerance of 39 bread wheat genotypes to end-season drought. The experimental design was Randomized Complete Block in three replications and the drought tolerance indices (SSI, STI, TOL, MP and GMP) were calculated for grain yield. The cultivar Cambin produced the highest grain yield under normal irrigation by 369.19 g m-2 while Arina had the highest yield (223.35 g m-2) under drought stress conditions. Stress tolerance (TOL) introduced Hindukesh, Iran2355 and Iran6476 as drought tolerant genotypes. Also, results showed that grain yield under stress and non-stress environments were highly correlated with the mean productivity (MP), the geometric mean productivity (GMP) and tolerance index (TOL). These genotypes could be further used in crosses for genetic studies and breeding programs for improvement tolerance to drought.

scholarly journals Water deficit stress tolerance assessment in barley cultivars using drought tolerance indices

2021 ◽  
Author(s):  
Md Habib ◽  
Md Mannan ◽  
Md Karim ◽  
Md Miah ◽  
Hari Singh
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Water Deficit ◽  
Geometric Mean ◽  
Research Work ◽  
Tolerance Index ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

Abstract Crop productivity is greatly affected by drought stress. Understanding the drought tolerance capability of the crop varieties available in a country is the foremost consideration for drought adaptation. The objective of this research work was to examine the drought tolerance potentiality of 5 cultivated barley varieties (BARI Barley5, BARI Barley6, BARI Barley7, BARI Barley8 and BARI Barley9) through calculating drought tolerance indices. A completely randomized design (CRD) with three replications was followed in the experiment, where crops were grown under control (80% of FC) and water deficit environment (50% of FC). Stress Tolerance (TOL), Mean Productivity (MP), Geometric Mean Productivity (GMP), Stress Susceptibility Index (SSI), Stress Tolerance Index (STI), Harmonic Mean (HAM), Yield Index (YI) and Yield Stability Index (YSI) were calculated based on grain yield under control and drought conditions. BARI Barley7 and BARI Barley8 were the most tolerant variety and BARI Barley9 considered as susceptible based on TOL and SSI. Drought tolerance indices like MP, HAM, GMP, TOL as well as STI were showed a high correlation with grain yield under both conditions and were recognized as appropriate indices to identify varieties with high grain yield and low sensitivity to drought stress.

scholarly journals Some aspects of mechanisms of NaCl stress tolerance in the seedlings of four rice genotypes

1970 ◽  
Vol 36 (2) ◽  
pp. 181-184
Author(s):  
ANM Alamgir ◽  
Mohammad Musa ◽  
Mohammad Yousuf Ali
Keyword(s):  
Atpase Activity ◽  
Stress Tolerance ◽  
Salinity Stress ◽  
Dry Matter ◽  
Nacl Stress ◽  
Tolerance Mechanism ◽  
High Dry Matter ◽  
Shoot Ratio ◽  
Rice Genotypes ◽  
Tolerance Indices

Biomass production under salt stress decreased with the sequence: IRATOM-24 > BR 9 > Nonabokra > Pokkali. In Pokkali root-shoot dry wt. was less affected and it maintained high root to shoot ratio (R/S) and their tolerance indices (TI). Salinity stress increased Na+, Cl- and decreased K+ and Ca+ contents and consequently their ratios in both root and shoot of the seedlings. Under stress proline level was increased in both root and shoot of the seedlings in all genotypes, the highest was observed in the root of Pokkali and in the shoot of IRATOM-24. Excepting BR 9 salinity increased protein content in other genotypes and among them Nonabokra maintained the highest protein level. Salinity inhibited the root ATPase activity in all except Pokkali. Efficiency of the maintenance of relatively high dry matter, R/S ratio, essential ions, K+ - Ca2+/ Na+ ion ratios, proline and protein contents in the seedlings including the root ATPase activity may be imp ortant aspects of NaCl stress tolerance mechanism as found in one or another rice genotype of the present work.   Key words: Salinity, Stress tolerance, Proline, Protein, ATPase activity DOI = 10.3329/bjb.v36i2.1510 Bangladesh J. Bot. 36(2): 181-184, 2007 (December)

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