scholarly journals Screening for Drought Tolerance in Maize (Zea mays L.) Germplasm Using Germination and Seedling Traits under Simulated Drought Conditions

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 565 ◽  
Author(s):  
Abdelfattah Badr ◽  
Hanaa H. El-Shazly ◽  
Rasha A. Tarawneh ◽  
Andreas Börner

Maize is known to be susceptible to drought stress, which negatively affects vegetative growth and biomass production, as well as the formation of reproductive organs and yield parameters. In this study, 27 responsive traits of germination (G) and seedlings growth were evaluated for 40 accessions of the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) germplasm collection, under no stress and simulated drought stress treatments by 10%, 15%, and 20% of polyethylene glycol (PEG). The three treatments significantly reduced G% and retarded seedlings growth, particularly the 15% and 20% PEG treatments; these two treatments also resulted in a significant increase of abnormal seedlings (AS). The heritability (H2) and correlations of the traits were estimated, and drought tolerance indices (DTIs) were calculated for traits and accessions. The H2 of G% values were reduced, and H2 for AS% increased as the PEG stress increased. Positive correlations were found between most trait pairs, particularly shoot and root traits, with 48 highly significant correlations under no stress and 25 highly significant correlations under the 10% PEG treatments, particularly for shoot and root traits. The medium to high heritability of shoot and root seedling traits provides a sound basis for further genetic analyses. PCA analysis clearly grouped accessions with high DTIs together and the accessions with low DTIs together, indicating that the DTI indicates the stress tolerance level of maize germplasm. However, the resemblance in DTI values does not clearly reflect the origin or taxonomic assignments to subspecies and varieties of the examined accessions.

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.


Biologia ◽  
2015 ◽  
Vol 70 (7) ◽  
Author(s):  
Parinyaphorn Ploenlap ◽  
Wattana Pattanagul

AbstractThe effects of drought and exogenous ABA on foliar anthocyanin accumulation and its role in drought tolerance were studied in two purple rice cultivars GS. No. 00621 and GS. No. 21427. The seedlings were grown for 14 days and separated into four groups including control (well-watered), drought (withholding water), ABA (foliar sprayed with 20 mg L−1 ABA and well-watered), ABA and drought (foliar sprayed with 20 mg L−1 ABA and withholding water). Drought was imposed by withholding water for 7 days. The results showed that drought significantly reduced root and shoot growth in GS. No. 00621, while had little effect on GS. No. 21427. Drought stress also induced anthocyanin overaccumulation in GS. No. 21427, whereas its content was reduced in GS. No. 00621. Exogenous ABA had no effect on anthocyanin in both wellwatered and drought conditions in both cultivars. Higher anthocyanin in GS. No. 21427 was coincided with higher DPPH scavenging ability, antioxidant enzyme activities as well as higher relative water content. It is, therefore, concluded that drought-induced anthocyanin overaccumulation may be different between purple rice cultivars and anthocyanin is beneficial for the response to drought stress by protecting plant antioxidant mechanism. Unlike anthocyanin in plant reproductive organs, exogenous ABA has no effect on foliar anthocyanin accumulation in purple rice. It is possible that anthocyanin accumulation in leaf and reproductive organs may be regulated differently or triggered by different mechanisms.


2019 ◽  
Author(s):  
Chao Cheng ◽  
Shutong Hu ◽  
Yun Han ◽  
Di Xia ◽  
Bang-Lian Huang ◽  
...  

Abstract Using RACE PCR, full length WRI1-like gene was amplified from yellow nutsedge. Conserved domain and phylogenetic analyses suggested it as WRI3/4-like gene. Tissue-specific expression data showed the highest expression in leaves, followed by roots while the lowest expression was detected in tuber. Transgenic Arabidopsis plants expressing nutsedge WRI3/4-like gene showed significantly improved tolerance to both PEG-simulated drought stress and real dehydration, compared with the wild type (WT). Under normal growth conditions, the expressions of key fatty acid biosynthesis genes was not significantly different between WT and transgenic lines, while the expressions of genes involved in cuticular wax biosynthesis was significantly higher in transgenic lines compared with the WT. The PEG-simulated drought stress did not induce any significant change in the expression of fatty acid and wax biosynthesis genes in WT plants, while the expression of fatty acid and wax biosynthesis genes was significantly increased in transgenic lines compared with WT as well as unstressed transgenic control. The expression of TAG1, the gene involved in triacylglycerol (TAG) accumulation, was significantly lower in the transgenic lines than that in the WT in normal growth conditions. Drought stress slightly decreased the expression of TAG1 in the WT, but significantly lowered it in transgenic lines compared with its unstressed transgenic control and WT. Consistent with gene expression data, the cuticular wax content in Arabidopsis leaves was significantly higher in the transgenic lines than in the WT, while the oil content was not significantly different. Our results indicated that WRI3/4-like gene from Cyperus esculentus improves drought tolerance in Arabidopsis probably by promoting cuticular wax biosynthesis and, hence, could be a valuable target for improving drought tolerance in crops through recombinant DNA technology.


2016 ◽  
Vol 19 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Chandrakant Singh ◽  
Vijay Kumar ◽  
Indivar Prasad ◽  
Vishal R. Patil ◽  
B. K. Rajkumar

2015 ◽  
Vol 21 ◽  
pp. 109-122 ◽  
Author(s):  
Soran Sharafi ◽  
Kazem Ghassemi Golezani ◽  
Soleyman Mohammadi ◽  
Shahram Lak ◽  
Behzad Sorkhy

Context: Evaluation of tolerance of different barley genotypes to drought stress, an experiment carried out in randomized block design (RCBD) with three replication during 2009-2010 growing seasons and 20 barley genotypes were studied in normal and water deficit in post anthesis stage conditions at the Saatloo Research Farm Azerbaiejan, Iran. Results: The result of variance analysis showed that there were highly significant differences between genotypes in all of the studied traits, also it was cleared that all of traits except spike length reduced in water deficit condition as compared to normal condition and seed yield, biomass and 1000 seed weight traits had the most reduction (31, 25 and 20 percent, respectively). To identify of tolerance barley genotypes to drought stress, drought tolerance indices (STI, TOL, SSI, MP, HM and GMP), correlation coefficients, principal components analysis and cluster analysis were used. The result of correlation coefficients indicated that there were significant and positive correlation between seed yield in normal and stress conditions and drought tolerance indices. Also the result of principal components analysis showed that two components justified 99% of total variations. MP, GMP, STI and HM indices and TOL and SSI indices had the most coefficients in the first and second component, respectively, so are named tolerance and sensitivity component, respectively. Conclusion: MP, HM, STI and GMP indices were appropriate indices to select of drought tolerance barley genotypes. On the other hand, the result of cluster analysis showed that 13, 14 and 7 genotypes and 18, 1 and 2 genotypes were tolerance and sensitivity genotypes to water deficit at post anthesis stage. DOI: http://dx.doi.org/10.3329/jbs.v21i0.22525 J. bio-sci. 21: 109-122, 2013


2021 ◽  
Vol 12 ◽  
Author(s):  
FengLei Sun ◽  
Qin Chen ◽  
QuanJia Chen ◽  
Menghui Jiang ◽  
Wenwei Gao ◽  
...  

Drought is one of the main abiotic stresses that seriously influences cotton production. Many indicators can be used to evaluate cotton drought tolerance, but the key indicators remain to be determined. The objective of this study was to identify effective cotton drought tolerance indicators from 19 indices, including morphology, photosynthesis, physiology, and yield-related indices, and to evaluate the yield potential of 104 cotton varieties under both normal and drought-stress field conditions. Combined with principal component analysis (PCA) and a regression analysis method, the results showed that the top five PCs among the 19, with eigenvalues &gt; 1, contributed 65.52, 63.59, and 65.90% of the total variability during 2016 to 2018, respectively, which included plant height (PH), effective fruit branch number (EFBN), single boll weight (SBW), transpiration rate (Tr) and chlorophyll (Chl). Therefore, the indicator dimension decreased from 19 to 5. A comparison of the 19 indicators with the 5 identified indicators through PCA and a combined regression analysis found that the results of the final cluster of drought tolerance on 104 cotton varieties were basically consistent. The results indicated that these five traits could be used in combination to screen cotton varieties or lines for drought tolerance in cotton breeding programs, and Zhong R2016 and Xin lu zao 45 exhibited high drought tolerance and can be selected as superior parents for good yield performance under drought stress.


Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 994
Author(s):  
Norain Jamalluddin ◽  
Festo J. Massawe ◽  
Sean Mayes ◽  
Wai Kuan Ho ◽  
Ajit Singh ◽  
...  

Amaranth (Amaranthus tricolor), an underutilized climate smart crop, is highly nutritious and possesses diverse drought tolerance traits, making it an ideal crop to thrive in a rapidly changing climate. Despite considerable studies on the growth and physiology of plants subjected to drought stress, a precise trait phenotyping strategy for drought tolerance in vegetable amaranth is still not well documented. In this study, two drought screening trials were carried out on 44 A. tricolor accessions in order to identify potential drought-tolerant A. tricolor germplasm and to discern their physiological responses to drought stress. The findings revealed that a change in stem biomass was most likely the main mechanism of drought adaptation for stress recovery, and dark-adapted quantum yield (Fv/Fm) could be a useful parameter for identifying drought tolerance in amaranth. Three drought tolerance indices: geometric mean productivity (GMP), mean productivity (MP) and stress tolerance index (STI) identified eight drought-tolerant accessions with stable performance across the two screening trials. The highly significant genotypic differences observed in several physiological traits among the amaranth accessions indicate that the amaranth panel used in this study could be a rich source of genetic diversity for breeding purposes for drought tolerance traits.


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