scholarly journals Maize (Zea mays L.) landraces classified by drought stress tolerance at the seedling stage

2021 ◽  
pp. 29
Author(s):  
Víctor A. González Hernández ◽  
Eleazar Lugo Cruz ◽  
Leopoldo E. Mendoza Onofre ◽  
Amalio Santacruz Varela ◽  
Ma. Alejandra Gutiérrez Espinosa ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Deficit ◽  
Recovery Period ◽  
Shoot Biomass ◽  
Limiting Factor ◽  
Stress Recovery ◽  
Total Biomass ◽  
Maize Landraces ◽  
Post Stress

Drought is the main limiting factor for maize production, and climate change can aggravate this water scarcity. One way to mitigate this problem is to plant drought tolerance maize genotypes. In landrace maize grown under rainfed conditions there are drought-adapted genotypes, which can be used in breeding programs for drought tolerance. The objective of this study was to evaluate the effect of an early water deficit on the seedling growth of 41 maize landraces from Nuevo León, Mexico, plus seven varieties, by means of drought tolerance indices based on biomass accumulation during both stress and post-stress recovery period, for identifying tolerant and susceptible genotypes. This study was performed at 2016 in Texcoco, Mexico (19°27’N, 98°54’W, 2241 masl). In the greenhouse, 96 treatments were compared (48 genotypes × two soil water regimes: without and with drought) under randomized complete blocks experimental design. After the drought stress period, normal irrigation was resumed for 15 days for recovery. In maize landraces there is genetic diversity in drought tolerance. Landraces GalTrini and SITexas outstanded as the most water deficit tolerant, whereas landraces Berrones, Rodeo, Sabanilla, Carmen, AraTrini and the inbred line L65 were the most drought susceptible. The total biomass measured before water stress was not related to drought adaptability. This study demonstrates that the post stress recovery is more important in drought stress adaptability than the drought resistance, regarding root biomass, shoot biomass and total biomass. Thus, to include the post stress recovery in drought tolerance studies can produce a more precise genotypic classification for drought stress resistance and adaptability.

scholarly journals QTL mapping reveals genomic regions for yield based on an incremental tolerance index to drought stress and related agronomic traits in canola

2020 ◽  
Vol 71 (6) ◽  
pp. 562
Author(s):  
Harsh Raman ◽  
Rosy Raman ◽  
Ky Mathews ◽  
Simon Diffey ◽  
Phil Salisbury
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Seed Yield ◽  
Irrigation Treatment ◽  
Shoot Biomass ◽  
Doubled Haploid Population ◽  
Limiting Factor ◽  
Tolerance Index ◽  
Flowering Locus ◽  
Genomic Regions

Drought stress, especially at the reproductive stage, is a major limiting factor that compromises the productivity and profitability of canola in many regions of the world. Improved genetics for drought tolerance would enable the identification and development of resilient cultivars, resulting in increased canola production. The main objective of the present study was to dissect the genetic basis of seed yield of canola under water-limited conditions. A doubled haploid population derived from a cross between two Australian parental lines, RP04 and Ag-Outback, was evaluated to identify the genetic variation in fractional normalised deviation vegetative index (NDVI), aboveground shoot biomass accumulation, flowering time and plasticity in seed yield under irrigated and rainfed field conditions in two consecutive years. An irrigation treatment was applied at the 50% flowering stage and an incremental drought tolerance index (DTI) was estimated for seed yield. By utilising a genetic linkage map based on 18851 genome-wide DArTseq markers, we identified 25 genomic regions significantly associated with different traits (logarithm of odds (LOD) ≥ 3), accounting for 5.5–22.3% of the genotypic variance. Three significant genomic regions on chromosomes A06, A10 and C04 were associated with DTI for seed yield. Some of the quantitative trait loci (QTL) were localised in the close proximity of candidate genes involved in traits contributing to drought escape and drought avoidance mechanisms, including FLOWERING LOCUS T (FT) and FLOWERING LOCUS C (FLC). Trait-marker associations identified herein can be validated across diverse environments, and the sequence-based markers may be used in a marker assisted selection breeding strategy to enhance drought tolerance in canola breeding germplasm.

scholarly journals QTL mapping reveals genomic regions for yield based on incremental tolerance index to drought stress and related agronomic traits in canola

2020 ◽  
Author(s):  
Harsh Raman ◽  
Rosy Raman ◽  
Ky Mathews ◽  
Simon Diffey ◽  
Phil Salisbury
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Seed Yield ◽  
Irrigation Treatment ◽  
Shoot Biomass ◽  
Doubled Haploid Population ◽  
Limiting Factor ◽  
Tolerance Index ◽  
Flowering Locus ◽  
Genomic Regions

AbstractDrought stress especially at the reproductive stage is a major limiting factor that compromises the productivity and profitability of canola in many regions of the world. Improved genetics for drought tolerance would enable the identification and development of resilient varieties, resulting in increased canola production. The main objective of this study was to dissect the genetic basis of seed yield under water-limited conditions in canola. A doubled haploid population derived from a cross between two Australian parental lines, RP04 and Ag-Outback, was evaluated to identify the genetic variation in fractional normalised deviation vegetative index (NDVI), above ground shoot biomass accumulation, flowering time, and plasticity in seed yield under irrigated and rainfed field conditions in two consecutive years. An irrigation treatment was applied at the 50% flowering stage and an incremental drought tolerance index (DTI) was estimated for seed yield. By utilising a genetic linkage map based on 18,851 genome-wide DArTseq markers, we identified 25 genomic regions significantly associated with different traits (LOD ≥ 3), accounting for 5.5 to 22.3% of the genotypic variance. Three significant genomic regions on chromosome A06, A10 and C04 were associated with DTI for seed yield. Some of the QTL were localised in the close proximity of candidates genes involved in traits contributing to drought escape and drought avoidance mechanisms, including FLOWERING LOCUS T (FT) and FLOWERING LOCUS C (FLC). Trait-marker associations identified herein can be validated across diverse environments, and the sequence based markers may be used in a marker assisted selection breeding strategy to enhance drought tolerance in canola breeding germplasm.

scholarly journals Exogenous Application of Brassinosteroid 24-Norcholane 22(S)-23-Dihydroxy Type Analogs to Enhance Water Deficit Stress Tolerance in Arabidopsis thaliana

2021 ◽  
Vol 22 (3) ◽  
pp. 1158
Author(s):  
Katy Díaz ◽  
Luis Espinoza ◽  
Rodrigo Carvajal ◽  
Evelyn Silva-Moreno ◽  
Andrés F. Olea ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Stress Tolerance ◽  
Water Deficit ◽  
Alternative Pathway ◽  
Recovery Period ◽  
Homogeneous Solution ◽  
Water Deficit Stress ◽  
Marker Genes ◽  
Exogenous Application

Brassinosteroids (BRs) are plant hormones that play an essential role in plant development and have the ability to protect plants against various environmental stresses, such as low and high temperature, drought, heat, salinity, heavy metal toxicity, and pesticides. Mitigation of stress effects are produced through independent mechanisms or by interaction with other important phytohormones. However, there are few studies in which this property has been reported for BRs analogs. Thus, in this work, the enhancement of drought stress tolerance of A. thaliana was assessed for a series of 2-deoxybrassinosteroid analogs. In addition, the growth-promoting activity in the Rice Lamina Inclination Test (RLIT) was also evaluated. The results show that analog 1 exhibits similar growth activity as brassinolide (BL; used as positive control) in the RLIT bioassay. Interestingly, both compounds increase their activities by a factor of 1.2–1.5 when they are incorporated to polymer micelles formed by Pluronic F-127. On the other hand, tolerance to water deficit stress of Arabidopsis thaliana seedlings was evaluated by determining survival rate and dry weight of seedlings after the recovery period. In both cases, the effect of analog 1 is higher than that exhibited by BL. Additionally, the expression of a subset of drought stress marker genes was evaluated in presence and absence of exogenous applied BRs. Results obtained by qRT-PCR analysis, indicate that transcriptional changes of AtDREBD2A and AtNCED3 genes were more significant in A. thaliana treated with analog 1 in homogeneous solution than in that treated with BL. These changes suggest the activation of alternative pathway in response to water stress deficit. Thus, exogenous application of BRs synthetic analogs could be a potential tool for improvement of crop production under stress conditions.

scholarly journals Sorghum in dryland: morphological, physiological, and molecular responses of sorghum under drought stress

Planta ◽  
2021 ◽  
Vol 255 (1) ◽  
Author(s):  
Kibrom B. Abreha ◽  
Muluken Enyew ◽  
Anders S. Carlsson ◽  
Ramesh R. Vetukuri ◽  
Tileye Feyissa ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Nutritional Quality ◽  
Substantial Reduction ◽  
Limiting Factor ◽  
Molecular Alterations ◽  
Germination Process ◽  
Effects Of Drought ◽  
Grain Yield And Quality ◽  
Source Sink

Abstract Main conclusion Droughts negatively affect sorghum’s productivity and nutritional quality. Across its diversity centers, however, there exist resilient genotypes that function differently under drought stress at various levels, including molecular and physiological. Abstract Sorghum is an economically important and a staple food crop for over half a billion people in developing countries, mostly in arid and semi-arid regions where drought stress is a major limiting factor. Although sorghum is generally considered tolerant, drought stress still significantly hampers its productivity and nutritional quality across its major cultivation areas. Hence, understanding both the effects of the stress and plant response is indispensable for improving drought tolerance of the crop. This review aimed at enhancing our understanding and provide more insights on drought tolerance in sorghum as a contribution to the development of climate resilient sorghum cultivars. We summarized findings on the effects of drought on the growth and development of sorghum including osmotic potential that impedes germination process and embryonic structures, photosynthetic rates, and imbalance in source-sink relations that in turn affect seed filling often manifested in the form of substantial reduction in grain yield and quality. Mechanisms of sorghum response to drought-stress involving morphological, physiological, and molecular alterations are presented. We highlighted the current understanding about the genetic basis of drought tolerance in sorghum, which is important for maximizing utilization of its germplasm for development of improved cultivars. Furthermore, we discussed interactions of drought with other abiotic stresses and biotic factors, which may increase the vulnerability of the crop or enhance its tolerance to drought stress. Based on the research reviewed in this article, it appears possible to develop locally adapted cultivars of sorghum that are drought tolerant and nutrient rich using modern plant breeding techniques.

Co-expression of xerophyte Zygophyllum xanthoxylum ZxNHX and ZxVP1-1 enhances salt and drought tolerance in transgenic Lotus corniculatus by increasing cations accumulation

2014 ◽  
Vol 41 (2) ◽  
pp. 203 ◽  
Author(s):  
Ai-Ke Bao ◽  
Yan-Wen Wang ◽  
Jie-Jun Xi ◽  
Chen Liu ◽  
Jin-Lin Zhang ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Water Deficit ◽  
Membrane Damage ◽  
Lotus Corniculatus ◽  
Shoot Biomass ◽  
Water Deficit Stress ◽  
Arid Environments ◽  
Salt And Drought Tolerance ◽  
Zygophyllum Xanthoxylum ◽  
Transgenic Lines

Lotus corniculatus L. is an important legume for forage, but is sensitive to salinity and drought. To develop salt- and drought-resistant L. corniculatus, ZxNHX and ZxVP1-1 genes encoding tonoplast Na+/H+ antiporter and H+-pyrophosphatase (H+-PPase) from a succulent xerophyte Zygophyllum xanthoxylum L., which is well adapted to arid environments through accumulating Na+ in its leaves, were transferred into this forage. We obtained the transgenic lines co-expressing ZxNHX and ZxVP1-1 genes (VX) as well as expressing ZxVP1-1 gene alone (VP). Compared with wild-type, both VX and VP transgenic lines grew better at 200 mM NaCl, and also exhibited higher tolerance and faster recovery from water-deficit stress: these performances were associated with more Na+, K+ and Ca2+ accumulation in their leaves and roots, which caused lower leaf solute potential and thus retained more water. Moreover, the transgenic lines maintained lower relative membrane permeability and higher net photosynthesis rate under salt or water-deficit stress. These results indicate that expression of tonoplast Na+/H+ antiporter and H+-PPase genes from xerophyte enhanced salt and drought tolerance of L. corniculatus. Furthermore, compared with VP, VX showed higher shoot biomass, more cations accumulation, higher water retention, lesser cell membrane damage and higher photosynthesis capacity under salt or water-deficit condition, suggesting that co-expression of ZxVP1-1 and ZxNHX confers even greater performance to transgenic L. corniculatus than expression of the single ZxVP1-1.

Two potato (Solanum tuberosum) varieties differ in drought tolerance due to differences in root growth at depth

2014 ◽  
Vol 41 (11) ◽  
pp. 1107 ◽  
Author(s):  
Jaime Puértolas ◽  
Carlos Ballester ◽  
E. David Elphinstone ◽  
Ian C. Dodd
Keyword(s):  
Solanum Tuberosum ◽  
Drought Tolerance ◽  
Root Growth ◽  
Water Deficit ◽  
Solanum Tuberosum L ◽  
Shoot Biomass ◽  
Genotypic Differences ◽  
Deep Soil ◽  
Soil Layers ◽  
Cultural Conditions

To test the hypothesis that root growth at depth is a key trait explaining some genotypic differences in drought tolerance in potato (Solanum tuberosum L.), two varieties (Horizon and Maris Piper) differing in drought tolerance were subjected to different irrigation regimes in pots in a glasshouse and in the field under a polytunnel. In the glasshouse, both cultivars showed similar gas exchange, leaf water potential, leaf xylem ABA concentration and shoot biomass independently of whether plants were grown under well watered or water deficit conditions. Under well watered conditions, root growth was three-fold higher in Horizon compared with Maris Piper, 3 weeks after emergence. Water deficit reduced this difference. In the polytunnel, applying 60% or less irrigation volume compared with full irrigation significantly decreased tuber yield in Maris Piper but not in Horizon. This was coincident with the higher root density of Horizon in deep soil layers (>40 cm), where water content was stable. The results suggest that early vigorous root proliferation may be a useful selection trait for maintaining yield of potato under restricted irrigation or rainfall, because it rapidly secures access to water stored in deep soil layers. Although selecting for vigorous root growth may assist phenotyping screening for drought tolerance, these varieties may require particular environmental or cultural conditions to express root vigour, such as sufficiently deep soils or sufficient water shortly after emergence.

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.

Nanosilicon-based recovery of barley (Hordeum vulgare) plants subjected to drought stress

2020 ◽  
Vol 7 (2) ◽  
pp. 443-461 ◽  
Author(s):  
Mansour Ghorbanpour ◽  
Hamid Mohammadi ◽  
Khalil Kariman
Keyword(s):  
Drought Stress ◽  
Hordeum Vulgare ◽  
Vegetative Growth ◽  
Silicon Nanoparticles ◽  
Stress Recovery ◽  
Recovery Performance ◽  
Potential Impact ◽  
Post Stress

The study explores the potential impact of silicon nanoparticles (Si NPs), in comparison with their bulk counterpart (silicate), on post-stress recovery performance of barley (Hordeum vulgare) seedlings under different drought stress intensities during vegetative growth.

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