Stress tolerance indices for the identification of low phosphorus tolerant introgression lines derived from Oryza rufipogon Griff.

2021 ◽  
pp. 1-11
Author(s):  
Basavaraj P. S. ◽  
Gireesh C. ◽  
Muralidhara Bharamappanavara ◽  
Manoj C. A. ◽  
Ishwarya Lakshmi V. G. ◽  
...  

Abstract Soil phosphorus (P) deficiency is one of the major challenges for the cultivation of rice worldwide because it limits the growth and productivity of the crop. Therefore, the ability to grow in P-deficit soils is an important trait for rice cultivation. O . rufipogon Griff., a wild relative of rice, is a source of genetic variation for low phosphorus tolerance. The present study was undertaken to identify low P stress-tolerant introgression lines by analysing stress tolerance indices of 40 introgression lines of O. rufipogon. The populations were screened under low soil P and normal soil P plots for two growing seasons. Based on yield under stress and normal conditions, we computed different stress indices, including stress tolerance index (STI), tolerance index, yield reduction ratio (YR), stress susceptibility index, yield stability index (YSI), yield index, per cent yield reduction and geometric mean productivity (GMP). The studies of correlation analysis, principal component analysis and clustering revealed that STI, YSI and GMP were ideal indices for the selection of genotypes that performed well under both stress and normal conditions. Based on these indices, introgression lines (IL-24, IL-29 and IL-32) were identified as promising low P tolerant lines, which exhibited better grain yield under both stress (YS) and normal (YP) conditions. These pre-breeding lines serve as valuable genetic resources for low P tolerance in rice breeding programmes across the world.

AGROFOR ◽  
2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Minka KOLEVA ◽  
Valentina DIMITROVA

Drought is a wide-spread problem seriously influencing production and quality ofcotton (Gossypium hirsutum L.), but development of resistant cultivars is hamperedby the lack of effective selection criteria. The objective of this study was toevaluate the ability of several selection indices to identify drought tolerant cultivarsunder different environmental conditions. Thirteen cotton cultivars were evaluatedunder both moisture stress (2016) and non-stress (2013) field environments using arandomized complete block design for each environment. Six drought toleranceindices including stress susceptibility index (SSI), stress tolerance index (STI),tolerance index (TOL), mean productivity (MP), geometric mean productivity(GMP) and mean harmonic productivity (HMP) were used. The significant andpositive correlation of yield of genotype under non-stress condition (Yp) and MP,GMP and STI showed that these indices were more effective in identifying highyielding cultivars under different moisture conditions. The results of calculatedgain from indirect selection in moisture stress environment would improve yieldbetter than selection from non moisture stress environment. Coton breeders should,therefore, take into account the stress severity of the environment in choosing anindex. The varieties Viki and Avangard-264 had the highest yields under non-stressconditions. Vega and Chirpan-539 varieties had a low yield potential and showed ahigh stress tolerance to drought.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Hossein Askari ◽  
Seiyed Kamal Kazemitabar ◽  
Hamid Najafi Zarrini ◽  
Mohammd Hossein Saberi

AbstractThis study was performed to assess several indices for identifying genotypes at germination stage with the best performance in salinity conditions. In order to evaluate the seed germination of barley genotypes in different levels of salt conditions, an experiment was conducted as factorial arrangement with a completely randomized design with 3 replications. The effect of salinity treatments was studied through an analysis of the germination, yielding results that show significant differences among genotypes. Stress tolerance index, stress tolerance, stress susceptibility index, germination reduction ratio, mean productivity and geometric mean productivity were used. The majority of used indices indicated that ESBYTM8910, 4 Shori and MBS8715 were the best barley genotypes showing the highest stress resistance for the greatest NaCl concentration. This result was similar to those obtained from the analysis of variance and statistical comparison of means of genotypes germination percentages. There were positive and strong correlations of germination percentage in normal and stress condition with STI in high levels of salinity. Thus, this correlation seems to be a useful indicator of tolerant genotypes at this stage.


Author(s):  
Alireza Daneshvar Hosseini ◽  
Ali Dadkhodaie ◽  
Bahram Heidari ◽  
Seyed Abdolreza Kazemeini

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.


2021 ◽  
Author(s):  
Md Habib ◽  
Md Mannan ◽  
Md Karim ◽  
Md Miah ◽  
Hari Singh

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.


2020 ◽  
Vol 18 (1) ◽  
pp. 19-27
Author(s):  
Smaranika Mishra ◽  
R. H. Laxman ◽  
K. Madhavi Reddy ◽  
R. Venugopalan

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.


2020 ◽  
Vol 115 (1) ◽  
pp. 105
Author(s):  
Sara KHOSRAVI ◽  
Reza AZIZINEZHAD ◽  
Amin BAGHIZADEH ◽  
Mahmood MALEKI

<p>This study was carried out on grain yield in wheat genotypes with the aim of assessing genetic potential of drought tolerance. The experiment was performed as split plot in the form of randomized complete block design with three replications under normal and drought stress conditions with 32 genotypes. Based on grain yield, and under the condition of non-stress and drought stress, 5 drought tolerance indices are estimated including Tolerance Index (TOL), Stress Tolerance (STI), Mean Productivity (MP), Geometric Mean (GMP) and, Harmonic Mean (HM) for all kinds of genotypes. The analysis of yield correlation and drought tolerance indices in two environments indicated that STI, MP, GMP, HM indices were the most suitable parameters for screening wheat genotypes. Principal components analysis exhibited that the 83 % of first principal component and the 15 % of second one justified the variation of the initial data. Drawing bi-plot diagram declared that Sabalan, Shabrang, Aria, Azar, Azadi, and T2 genotypes were highly functional and resistant to drought stress.</p>


2017 ◽  
Vol 41 (6) ◽  
pp. 616-625 ◽  
Author(s):  
Ercan Ekbic ◽  
Cagri Cagıran ◽  
Kursat Korkmaz ◽  
Malik Arsal Kose ◽  
Veysel Aras

ABSTRACT Salt stress is the most significant constraint for agricultural production in arid and semi-arid regions. Thus, genetically improved stress-tolerant varieties are needed for the future. The identification of salt-tolerant genotypes is the starting point for such breeding studies. This study was conducted to determine and assess the tolerance of different watermelon genotypes under saline conditions. Twenty-two watermelon genotypes and accessions were grown in pots with 3 kg of soil in four saline stress conditions (0 mmol kg-1 as the control, 25, 50 and 100 mmol kg-1 NaCl). The detrimental effects of salt stress on the plants were evident with increasing doses of NaCl. Stress indices calculated over the plant dry weights under the 100 mmol kg-1 salinity level were used to assess the salt tolerance of the genotypes. Stress intensity was calculated as 0.76. Such a value indicated that the highest dose of salt exerted severe stress on the plants. The G04, G14 and G21 genotypes were considered to be salt tolerant, since these genotypes showed the highest values of K/Na and Ca/Na ratios in the plant tissue. The losses in dry mass at severe salt stress reached 75.48%. In principal component analyses, the genotypes had positive correlations with stress tolerance indices of MP (mean productivity), GMP (geometric mean productivity) and STI (stress tolerance index). The GMP and STI indices indicated that G04 (a member of Citrullus colocynthis), G14 and G21 could be prominent sources to develop salt tolerance.


2012 ◽  
Vol 1 (3) ◽  
pp. 543 ◽  
Author(s):  
H. Moradi ◽  
G A. Akbari ◽  
S. Khavari Khorasani ◽  
H A. Ramshini

In order to study the effect of drought stress on morphophysiologic characteristics,yield and yield components of 8 new hybrids of corn (Zea maize L.) and KSC704commercial hybrid as control resistant to drought and warm (which were bred andscreened in Khozestan province condition), an experiment was conducted in aRandomized Complete Block Design (RCBD) with three replications underdrought stress and normal irrigation at Khorasan-Razavi Agriculture ResearchCenter, Mashhad, Iran on June 10, 2011. The results of analyze variance showedthat under normal irrigation and drought condition, there was a significantdifference (p<0.01) between the hybrids. Mean comparison of hybrids revealedthat in normal irrigation H6 and in drought stress H8 hybrid had the maximumgrain yield (12.85 and 6.75 ton/ha, respectively). Based on the grain yields ofstudied hybrids, stress tolerance index (STI), stress susceptibility index (SSI),tolerance index (TOI), mean productivity (MP), geometric mean productivity(GMP), harmonic mean (HM) and golden mean (GM) were estimated. Resultsshowed that among drought tolerance indices, MP, GMP, STI and HM were thebest indices for corn and KSC704 hybrid and H4 had the highest tolerance todrought in Mashhad weather condition.


2021 ◽  
Vol 117 (1) ◽  
pp. 1
Author(s):  
Pooran GOLKAR ◽  
Esmaeil HAMZEH ◽  
Seyed Ali Mohammad MIRMOHAMMADY MAIBODY

<p>Improvement of elite safflower genotypes for drought-tolerance is hampered by a deficiency of effective selection criteria. The present study evaluated 100 genotypes of safflower in terms of their drought tolerance over a period of three years (2016–2018) under both non-stress and drought-stress conditions. The eight drought-tolerance indices of tolerance index (TOL), mean productivity (MP), geometric mean productivity (GMP), stress susceptibility index (SSI), stress tolerance index (STI), yield stability index (YSI), drought resistance index (DI), and harmonic mean (HARM) were calculated based on seed yield under drought (Y<sub>s</sub>) and non-drought (Y<sub>p</sub>) conditions. A high genetic variation was found in drought tolerance among the genotypes studied. The MP, GMP, and STI indices were able to discriminate between tolerant and drought-sensitive genotypes. Plots of the first and second principal components identified drought-tolerant genotypes averaged over the three study years. Cluster analysis divided the genotypes into three distinct groups using the drought tolerance indices. Ultimately, eight genotypes (namely, G<sub>3</sub>, G<sub>11</sub>, G<sub>13</sub>, G<sub>24</sub>, G<sub>33</sub>, G<sub>47</sub>, G<sub>58</sub>, and G<sub>61</sub>) from different origins were detected as more tolerant to drought stress suitable for use in safflower breeding programs in drought-affected areas. The most tolerant and susceptible genotypes could be exploited to produce mapping populations for drought tolerance breeding programs in safflower.</p>


2018 ◽  
Vol 10 (4) ◽  
pp. 575-583 ◽  
Author(s):  
Fereshteh JOKAR ◽  
Rahmatollah KARIMIZADEH ◽  
Asad MASOUMIASL ◽  
Reza AMIRI FAHLIANI

Durum wheat (Triticum durum L.) is used for the preparation of multiple food products, including pasta and bread. Its production is restricted due to diverse environmental stresses i.e. drought and heat stress. Here, comparative analysis of durum wheat varieties was done by studying canopy temperature depression (CTD) and chlorophyll content (CHL), yield and yield contributing traits to evaluate their performance under stress and low stress conditions. Twelve durum wheat genotypes were studied under stressful and low-stress conditions in Gachsaran region of Iran. CTD and CHL were measured at two stages, from the emergence of fifty percent of inflorescence (ZGS 54) to watery ripe stage (ZGS 71). According to stress tolerance index (STI), mean productivity (MP) and geometric mean productivity (GMP) indices, genotype G10 exhibited the most, while genotype G6, the least relative tolerance, respectively. Based on MP and GMP, genotype G10 was found to be drought tolerant, while genotype G2 displayed the lowest amount of MP and GMP. Therefore these genotypes are recommended to be used as genitors in artificial hybridization for improvement of drought tolerance in other cultivars. All indices had high correlation with grain yield under stress and non-stress condition, indicating more suitability of these indices for selection of resistant genotype. Results of the present study showed that among drought tolerance indices, harmonic mean (HM), GMP, CTD and modified STI index (K2STI) can be used as the most suitable indicators for screening drought tolerant cultivars.


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