Genetic gain in grain yield and drought tolerance of durum wheat breeding lines under rainfed conditions in Iran

2012 ◽  
Vol 60 (4) ◽  
pp. 417-432 ◽  
Author(s):  
R. Mohammadi

The main objective of this study was to evaluate the genetic gain for grain yield, yield attributes and drought tolerance of 11 durum breeding lines and also to compare it with one modern cultivar and two durum and bread wheat landraces in contrasting environment groups in a period of four cropping seasons (2005–09) within the Iran/ICARDA joint project for moderately cold rainfed areas of Iran. The significant genotype × year interaction indicated that the average yield performance of genotypes across environments was not consistent over the years. Genetic gain (%) for grain yield was distinguishable between the stressed and non-stressed environments. A positive genetic gain (27.7 to 23.9%) was observed in the non-stressed environment and a negative genetic gain (−11.5 to −24.1%) in the stressed environment for the breeding lines, compared to the landraces, suggesting that the evaluation of breeding materials under non-stressed conditions should be continued. Unlike the modern cultivar, the landraces were low yielding, and less responsive to non-stressed environments for grain yield and yield attributes. The drought resistance indices, i.e. tolerance index (TOL) and stress susceptibility index (SSI), were better in landraces than breeding lines, while the drought tolerance indices, i.e. stress tolerance index (STI) and drought response index (DRI), were better in breeding lines. In contrast with landraces, the modern cultivar and the breeding lines showed significant changes for both grain yield and drought tolerance.

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 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>


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>


2021 ◽  
Vol 11 ◽  
Author(s):  
Anjuman Arif ◽  
Najma Parveen ◽  
Muhammad Qandeel Waheed ◽  
Rana Muhammad Atif ◽  
Irem Waqar ◽  
...  

This study was planned with the purpose of evaluating the drought tolerance of advanced breeding lines of chickpea in natural field conditions. Two methods were employed to impose field conditions; the first: simulating drought stress by growing chickpea genotypes at five rainfed areas, with Faisalabad as the non-stressed control environment; and the second: planting chickpea genotypes in spring to simulate a drought stress environment, with winter-sowing serving as the non-stressed environment. Additive main effects and multiplicative interaction (AMMI) and generalized linear models (GLM) models were both found to be equally effective in extracting main effects in the rainfed experiment. Results demonstrated that environment influenced seed yield, number of primary and secondary branches, number of pods, and number of seeds most predominantly; however, genotype was the main source of variation in 100 seed weight and plant height. The GGE biplot showed that Faisalabad, Kallur Kot, and Bhakkar were contributing the most in the GEI, respectively, while Bahawalpur, Bhawana, and Karor were relatively stable environments, respectively. Faisalabad was the most, and Bhakkar the least productive in terms of seed yield. The best genotypes to grow in non-stressed environments were CH39/08, CH40/09, and CH15/11, whereas CH28/07 and CH39/08 were found suitable for both conditions. CH55/09 displayed the best performance in stress conditions only. The AMMI stability and drought-tolerance indices enabled us to select genotypes with differential performance in both conditions. It is therefore concluded that the spring-sown experiment revealed a high-grade drought stress imposition on plants, and that the genotypes selected by both methods shared quite similar rankings, and also that manually computed drought-tolerance indices are also comparable for usage for better genotypic selections. This study could provide sufficient evidence for using the aforementioned as drought-tolerance evaluation methods, especially for countries and research organizations who have limited resources and funding for conducting multilocation trials, and performing sophisticated analyses on expensive software.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0242472
Author(s):  
A. S. Nehe ◽  
M. J. Foulkes ◽  
I. Ozturk ◽  
A. Rasheed ◽  
L. York ◽  
...  

Bread wheat (Triticum aestivum L) is one of the three main staple crops worldwide contributing 20% calories in the human diet. Drought stress is the main factor limiting yields and threatening food security, with climate change resulting in more frequent and intense drought. Developing drought-tolerant wheat cultivars is a promising way forward. The use of holistic approaches that include high-throughput phenotyping and genetic markers in selection could help in accelerating genetic gains. Fifty advanced breeding lines were selected from the CIMMYT Turkey winter wheat breeding program and studied under irrigated and semiarid conditions in two years. High-throughput phenotyping was done for wheat crown root traits and canopy senescence dynamics using vegetation indices (green area using RGB images and Normalized Difference Vegetation Index using spectral reflectance). In addition, genotyping by KASP markers for adaptability genes was done. Overall, under semiarid conditions yield reduced by 3.09 t ha-1 (-46.8%) compared to irrigated conditions. Genotypes responded differently under drought stress and genotypes 39 (VORONA/HD24-12//GUN/7/VEE#8//…/8/ALTAY), 18 (BiII98) and 29 (NIKIFOR//KROSHKA) were the most drought tolerant. Root traits including shallow nodal root angle under irrigated conditions and root number per shoot under semiarid conditions were correlated with increased grain yield. RGB based vegetation index measuring canopy green area at anthesis was better correlated with GY than NDVI was with GY under drought. The markers for five established functional genes (PRR73.A1 –flowering time, TEF-7A –grain size and weight, TaCwi.4A - yield under drought, Dreb1- drought tolerance, and ISBW11.GY.QTL.CANDIDATE- grain yield) were associated with different drought-tolerance traits in this experiment. We conclude that–genotypes 39, 18 and 29 could be used for drought tolerance breeding. The trait combinations of canopy green area at anthesis, and root number per shoot along with key drought adaptability makers (TaCwi.4A and Dreb1) could be used in screening drought tolerance wheat breeding lines.


2019 ◽  
Vol 11 (32) ◽  
pp. 11-21
Author(s):  
ali eftekhari ◽  
amin baghizadeh ◽  
rooholah abdshahi ◽  
mohamad mehdi yaghubi ◽  
◽  
...  

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Waltram Ravelombola ◽  
Ainong Shi ◽  
Bao-Lam Huynh

AbstractCowpea is a nutrient-dense legume that significantly contributes to the population’s diet in sub-Saharan Africa and other regions of the world. Improving cowpea cultivars to be more resilient to abiotic stress such as drought would be of great importance. The use of a multi-parent advanced generation intercross (MAGIC) population has been shown to be efficient in increasing the frequency of rare alleles that could be associated with important agricultural traits. In addition, drought tolerance index has been reported to be a reliable parameter for assessing crop tolerance to water-deficit conditions. Therefore, the objectives of this study were to evaluate the drought tolerance index for plant growth habit, plant maturity, flowering time, 100-seed weight, and grain yield in a MAGIC cowpea population, to conduct genome-wide association study (GWAS) and identify single nucleotide polymorphism (SNP) markers associated with the drought tolerance indices, to investigate the potential relationship existing between the significant loci associated with the drought tolerance indices, and to conduct genomic selection (GS). These analyses were performed using the existing phenotypic and genotypic data published for the MAGIC population which consisted of 305 F8 recombinant inbred lines (RILs) developed at University of California, Riverside. The results indicated that: (1) large variation in drought tolerance indices existed among the cowpea genotypes, (2) a total of 14, 18, 5, 5, and 35 SNPs were associated with plant growth habit change due to drought stress, and drought tolerance indices for maturity, flowering time, 100-seed weight, and grain yield, respectively, (3) the network-guided approach revealed clear interactions between the loci associated with the drought tolerance traits, and (4) the GS accuracy varied from low to moderate. These results could be applied to improve drought tolerance in cowpea through marker-assisted selection (MAS) and genomic selection (GS). To the best of our knowledge, this is the first report on marker loci associated with drought tolerance indices in cowpea.


2021 ◽  
Vol 12 ◽  
Author(s):  
Harsimardeep S. Gill ◽  
Jyotirmoy Halder ◽  
Jinfeng Zhang ◽  
Navreet K. Brar ◽  
Teerath S. Rai ◽  
...  

Genomic prediction is a promising approach for accelerating the genetic gain of complex traits in wheat breeding. However, increasing the prediction accuracy (PA) of genomic prediction (GP) models remains a challenge in the successful implementation of this approach. Multivariate models have shown promise when evaluated using diverse panels of unrelated accessions; however, limited information is available on their performance in advanced breeding trials. Here, we used multivariate GP models to predict multiple agronomic traits using 314 advanced and elite breeding lines of winter wheat evaluated in 10 site-year environments. We evaluated a multi-trait (MT) model with two cross-validation schemes representing different breeding scenarios (CV1, prediction of completely unphenotyped lines; and CV2, prediction of partially phenotyped lines for correlated traits). Moreover, extensive data from multi-environment trials (METs) were used to cross-validate a Bayesian multi-trait multi-environment (MTME) model that integrates the analysis of multiple-traits, such as G × E interaction. The MT-CV2 model outperformed all the other models for predicting grain yield with significant improvement in PA over the single-trait (ST-CV1) model. The MTME model performed better for all traits, with average improvement over the ST-CV1 reaching up to 19, 71, 17, 48, and 51% for grain yield, grain protein content, test weight, plant height, and days to heading, respectively. Overall, the empirical analyses elucidate the potential of both the MT-CV2 and MTME models when advanced breeding lines are used as a training population to predict related preliminary breeding lines. Further, we evaluated the practical application of the MTME model in the breeding program to reduce phenotyping cost using a sparse testing design. This showed that complementing METs with GP can substantially enhance resource efficiency. Our results demonstrate that multivariate GS models have a great potential in implementing GS in breeding programs.


2019 ◽  
Vol 1 (1) ◽  
pp. p18
Author(s):  
Iancu Paula ◽  
Păniță Ovidiu ◽  
Soare Marin

Water is essential to maximize crop yield and quality. This natural resource has assumed huge importance, especially in the warmest areas, where drought and environmental degradation has affected agricultural production. In order to identify drought tolerance of some groundnut genotypes and to investigate the relationships between seed yield, quality and drought tolerance indices a study was made using 10 promising genotypes. The experiment was carried out during 2014-2017 and sowed under randomized block design with four replicates. It included three factors: two levels of irrigation (a1 – non - irrigated and a2 - irrigated), two levels of fertilization (b1 – non-fertilized and b2 - 100 active Nitrogen/ha) and genotype (C1-C10). Seed yield depending on the influence of the factor, varied from 535.95 Kg/ha (non-irrigated) to 2020.95 Kg/ha (irrigated); from 1055.30 Kg/ha (non-fertilized) to 1501 Kg/ha (fertilized) and from 1111.30 Kg/ha to 1388 Kg/ha depending on genotype. Same influence factors for protein content varied from 25.65% (irrigated) to 28.61% (non-irrigated); from 26.33% (non-fertilized) to 27.93% (fertilized) and from 25.59% to 28.52% depending on genotype. Stress susceptibility index (SSI) varied from 0.964 to 1.040; Stress Tolerance Index (STI) from 0.138 to 0.435; Mean Productivity (MP) from 883.5 to 1616.0; Geometric Mean Productivity (GMP) from 750.3 to 1332.7; Tolerance index (TOL) from 933.0 to 1844.0; Harmonic Mean (HM) from 637.2 to 1099.0; Yield Index (YI) 0.777 to 1.308 and Yield Stability Index (YSI) from 0.236 to 0.309. High values of SSI, STI, YI, DI, RDI and SSPI indicate drought tolerance and those variants present high stability.


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