scholarly journals QTL Mapping for Seed Germination Response to Drought Stress in Brassica napus

2021 ◽  
Vol 11 ◽  
Author(s):  
Mahmoud Gad ◽  
Hongbo Chao ◽  
Huaixin Li ◽  
Weiguo Zhao ◽  
Guangyuan Lu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Brassica Napus ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Germination Percentage ◽  
Shoot Length ◽  
Stress Index ◽  
Phenotypic Analysis ◽  
Genetic Characteristics ◽  
Physical Maps

Drought stress is one of the most environmental abiotic stresses affecting seed germination and crop growth. In the present study, the genetic characteristics of seed germination under drought stress in a Brassica napus double haploid population were analyzed. Five germination-related indexes, including germination percentage (GP), root length (RL), shoot length (SL), fresh weight (FW), and root-to-shoot length ratio (R/S) under control and drought stress, were calculated, and the drought stress index (DSI), including DSI-GP, DSI-RL, DSI-SL, DSI-FW, and DSI-R/S, was determined using the quantitative trait loci (QTLs) analysis based on high-density genetic linkage map. The phenotypic analysis indicated that the R/S is an effective morphological trait in the determination of drought tolerance in the seedling stage. Thirty-nine identified QTLs were observed for these traits and then integrated into 36 consensus QTLs, in which 18 QTLs were found to affect the DSI of four traits (GP, RL, SL, and R/S). Based on the co-linearity between genetic and physical maps of B. napus, 256 candidate genes were detected, and 128 genes have single-nucleotidepolymorphisms/insertion–deletion (SNP/InDel) variations between two parents, some of which were associated with the drought stress tolerance (for example, BnaC03g32780D, BnaC03g37030D, and BnaC09g27300D). The present results laid insights into drought tolerance and its genetic bases in B. napus.

Evaluation of green gram genotypes for drought tolerance by PEG (polyethylene glycol) induced drought stress at seedling stage

2019 ◽  
Author(s):  
M. Jincya ◽  
V. Babu Rajendra Prasad ◽  
P. Jeyakumara ◽  
A. Senthila ◽  
N. Manivannan
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Moisture Stress ◽  
Germination Percentage ◽  
Seedling Stage ◽  
Green Gram ◽  
Stress Index ◽  
Seedling Mortality ◽  
Seed Vigour ◽  
Selection Of

Drought stress is one of the major constraints for pulse production which negatively affecting its growth and production. Screening and selection of desirable genotypes for drought tolerance is the first and foremost important step in pulse breeding program. In green gram standardization for moisture stress was done under laboratory conditions using various concentration of PEG 6000 and 50% seedling mortality was observed at 0.5 MPa of moisture stress. Using this level of moisture stress 108 green gram genotypes were screened for their drought tolerance at seedling level and the following parameters viz., germination percentage, promptness index, radicle length, root length stress index, germination stress index and seed vigour were recorded. Observations revealed that the following green gram genotypes COGG 1332, VGG 16069, VGG 17003, VGG 17004, VGG 17009, VGG 17019 and VGG 17045 were found highly tolerant to moisture stress at seedling stage.

Seed-germination response of Leymus chinensis to cold stratification in a range of temperatures, light and low water potentials under salt and drought stresses

2017 ◽  
Vol 68 (2) ◽  
pp. 188 ◽  
Author(s):  
Jixiang Lin ◽  
Yujie Shi ◽  
Shuang Tao ◽  
Xingyang Yu ◽  
Dafu Yu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Northeast China ◽  
Germination Percentage ◽  
Leymus Chinensis ◽  
Grass Species ◽  
Cold Stratification ◽  
Effective Measure ◽  
Salt And Drought Stresses

Leymus chinensis has important forage value and is considered a useful grass species for grassland restoration in Northeast China. However, little information exists concerning the germination responses of this species to interactions of cold stratification, light, temperature and low water potential caused by salinity and drought. Experiments were conducted in growth chambers, and the results showed that in all conditions of light, temperature and water stresses, the germination percentages of cold-stratified seeds were higher than of non-stratified seeds. Light had an inhibitory effect on germination percentage under both non-saline and salt stress conditions; darkness is beneficial for germination of this species. In addition, seeds germinated much better under alternating temperature regimes than under constant temperatures. Both salt and drought stresses decreased the germination percentage of Leymus chinensis, but the reductions under drought stress were much greater. Moreover, after being transferred to distilled water, most non-germinated seeds under drought stress germinated well, and the total percentage reached that of the non-saline condition level. Therefore, cold stratification is an effective measure to increase seed germination and salt or drought tolerance, especially in darkness. We conclude that Leymus chinensis has definite salt and drought tolerance during the germination stage and it is a promising species for the restoration of deteriorated grassland in Northeast China.

scholarly journals Applying RGB- and Thermal-Based Vegetation Indices from UAVs for High-Throughput Field Phenotyping of Drought Tolerance in Forage Grasses

2021 ◽  
Vol 13 (1) ◽  
pp. 147
Author(s):  
Tom De Swaef ◽  
Wouter H. Maes ◽  
Jonas Aper ◽  
Joost Baert ◽  
Mathias Cougnon ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Lolium Perenne ◽  
High Throughput ◽  
Festuca Arundinacea ◽  
Stress Index ◽  
Forage Grasses ◽  
Crop Water Stress Index ◽  
Ploidy Levels ◽  
Field Phenotyping

The persistence and productivity of forage grasses, important sources for feed production, are threatened by climate change-induced drought. Breeding programs are in search of new drought tolerant forage grass varieties, but those programs still rely on time-consuming and less consistent visual scoring by breeders. In this study, we evaluate whether Unmanned Aerial Vehicle (UAV) based remote sensing can complement or replace this visual breeder score. A field experiment was set up to test the drought tolerance of genotypes from three common forage types of two different species: Festuca arundinacea, diploid Lolium perenne and tetraploid Lolium perenne. Drought stress was imposed by using mobile rainout shelters. UAV flights with RGB and thermal sensors were conducted at five time points during the experiment. Visual-based indices from different colour spaces were selected that were closely correlated to the breeder score. Furthermore, several indices, in particular H and NDLab, from the HSV (Hue Saturation Value) and CIELab (Commission Internationale de l’éclairage) colour space, respectively, displayed a broad-sense heritability that was as high or higher than the visual breeder score, making these indices highly suited for high-throughput field phenotyping applications that can complement or even replace the breeder score. The thermal-based Crop Water Stress Index CWSI provided complementary information to visual-based indices, enabling the analysis of differences in ecophysiological mechanisms for coping with reduced water availability between species and ploidy levels. All species/types displayed variation in drought stress tolerance, which confirms that there is sufficient variation for selection within these groups of grasses. Our results confirmed the better drought tolerance potential of Festuca arundinacea, but also showed which Lolium perenne genotypes are more tolerant.

Phytohormone cross-talk and antioxidant gadgets tussles osmotic stress in indigenous rice landraces during seed germination

2020 ◽  
Author(s):  
R. Anupriya ◽  
Sugitha Thankappan ◽  
A. Senthil ◽  
D. Rajakumar ◽  
Geetha S ◽  
...  
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Cross Talk ◽  
Tamil Nadu ◽  
Critical Role ◽  
Hydrolytic Enzyme ◽  
Rice Landraces ◽  
Drought Tolerant ◽  
Root And Shoot Length

Abstract Seed germination plays a critical role in determining rice productivity under drought stress. We evaluated 100 traditional rice landraces originated from different agro-ecological zones of Tamil Nadu along with drought- susceptible (IR 64) and drought- tolerant (IR 64 DRT) checks. Moisture stress was induced using PEG 6000 and screening done over a range of osmotic potentials (-) 10 bars, (-) 12.5 bars and (-)15 bars for a period of 5 d. Physio-morphological traits such as germination rate, survival per cent, root and shoot length, vigor index, RS ratio and relative water content (RWC) were assessed during early drought stress. We observed significant changes in the seed macromolecules, phytohormone levels (GA and IAA), osmolytes and antioxidant responses (catalase and superoxide dismutase) between drought stress and control treatments. Kuliyadichan registered significantly higher IAA and GA (44% and 35% respectively over drought tolerant check IR 64 DRT) at drought stress, whereas all the landraces showed an elevated catalase activity. In PC analysis, first three PCs captured 88.93% of the total variation; significant differences were detected among genotypes with respect to the studied parameters. Six traditional landraces such as Kuliyadichan, Rajalakshmi, Sabhagidhan, Nootripathu, Chandaikar and Mallikar were selected and their inherent drought tolerance was associated with metabolic responses viz., triggered hydrolytic enzyme activities, hormonal cross-talk, ROS signaling and catalase under drought stress compared to drought sensitive IR64. Hence, these genotypes can be used as potential donor candidates towards genetic improvement of drought tolerance in rice.

scholarly journals BrEXLB1, a Brassica rapa Expansin-Like B1 Gene Is Associated with Root Development, Drought Stress Response, and Seed Germination

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 404 ◽  
Author(s):  
Muthusamy Muthusamy ◽  
Joo Yeol Kim ◽  
Eun Kyung Yoon ◽  
Jin A. Kim ◽  
Soo In Lee
Keyword(s):  
Abiotic Stress ◽  
Drought Stress ◽  
Stress Response ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Root Growth ◽  
Brassica Rapa ◽  
Root Development ◽  
Clubroot Disease ◽  
Qrt Pcr

Expansins are structural proteins prevalent in cell walls, participate in cell growth and stress responses by interacting with internal and external signals perceived by the genetic networks of plants. Herein, we investigated the Brassica rapa expansin-like B1 (BrEXLB1) interaction with phytohormones (IAA, ABA, Ethephon, CK, GA3, SA, and JA), genes (Bra001852, Bra001958, and Bra003006), biotic (Turnip mosaic Virus (TuMV), Pectobacterium carotovorum, clubroot disease), and abiotic stress (salt, oxidative, osmotic, and drought) conditions by either cDNA microarray or qRT-PCR assays. In addition, we also unraveled the potential role of BrEXLB1 in root growth, drought stress response, and seed germination in transgenic Arabidopsis and B. rapa lines. The qRT-PCR results displayed that BrEXLB1 expression was differentially influenced by hormones, and biotic and abiotic stress conditions; upregulated by IAA, ABA, SA, ethylene, drought, salt, osmotic, and oxidative conditions; and downregulated by clubroot disease, P. carotovorum, and TuMV infections. Among the tissues, prominent expression was observed in roots indicating the possible role in root growth. The root phenotyping followed by confocal imaging of root tips in Arabidopsis lines showed that BrEXLB1 overexpression increases the size of the root elongation zone and induce primary root growth. Conversely, it reduced the seed germination rate. Further analyses with transgenic B. rapa lines overexpressing BrEXLB1 sense (OX) and antisense transcripts (OX-AS) confirmed that BrEXLB1 overexpression is positively associated with drought tolerance and photosynthesis during vegetative growth phases of B. rapa plants. Moreover, the altered expression of BrEXLB1 in transgenic lines differentially influenced the expression of predicted BrEXLB1 interacting genes like Bra001852 and Bra003006. Collectively, this study revealed that BrEXLB1 is associated with root development, drought tolerance, photosynthesis, and seed germination.

scholarly journals Seed Priming: A Feasible Strategy to Enhance Drought Tolerance in Crop Plants

2020 ◽  
Vol 21 (21) ◽  
pp. 8258 ◽  
Author(s):  
Vishvanathan Marthandan ◽  
Rathnavel Geetha ◽  
Karunanandham Kumutha ◽  
Vellaichamy Gandhimeyyan Renganathan ◽  
Adhimoolam Karthikeyan ◽  
...  
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Drought Tolerance ◽  
Defense Mechanism ◽  
Seed Priming ◽  
Crop Productivity ◽  
Crop Plants ◽  
Complex Nature ◽  
Efficient Manner ◽  
Farming Community

Drought is a serious threat to the farming community, biasing the crop productivity in arid and semi-arid regions of the world. Drought adversely affects seed germination, plant growth, and development via non-normal physiological processes. Plants generally acclimatize to drought stress through various tolerance mechanisms, but the changes in global climate and modern agricultural systems have further worsened the crop productivity. In order to increase the production and productivity, several strategies such as the breeding of tolerant varieties and exogenous application of growth regulators, osmoprotectants, and plant mineral nutrients are followed to mitigate the effects of drought stress. Nevertheless, the complex nature of drought stress makes these strategies ineffective in benefiting the farming community. Seed priming is an alternative, low-cost, and feasible technique, which can improve drought stress tolerance through enhanced and advanced seed germination. Primed seeds can retain the memory of previous stress and enable protection against oxidative stress through earlier activation of the cellular defense mechanism, reduced imbibition time, upsurge of germination promoters, and osmotic regulation. However, a better understanding of the metabolic events during the priming treatment is needed to use this technology in a more efficient way. Interestingly, the review highlights the morphological, physiological, biochemical, and molecular responses of seed priming for enhancing the drought tolerance in crop plants. Furthermore, the challenges and opportunities associated with various priming methods are also addressed side-by-side to enable the use of this simple and cost-efficient technique in a more efficient manner.

scholarly journals Effect of some botanical fungicide and chemicals as forest seed dressing  on the quality of the seeds: تأثير بعض مبيدات الفطريات والكيمياويات النباتية في تلبيس بذور الغابات  على جودة البذور

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Shler Hassan Mahmood, Jalal Hama Salih Ismael
Keyword(s):  
Seed Germination ◽  
Root Length ◽  
Germination Percentage ◽  
Shoot Length ◽  
Salix Alba ◽  
Seed Dressing ◽  
Number Of Leaves ◽  
Petri Plate ◽  
Local Plants ◽  
The University

An experiment was conducted to study the antifungal activity of different concentrations aqueous extracts from three local plants, Hypericum triquetrifolium, Salix alba, Salvia rosmarinus and also different concentrations of fungicide (Captan) and Salicylic acid were evaluated for their efficacy as seed dressing on Catalpa and Albizia that seeds were soaked separately for 30 mints in various concentrations of aqueous extract and fungicide. Forest seeds were grown in pots which were inoculated by Sclerotinia sclerotiorum and Fusarium oxysporum that one petri plate/ pot in 2018 in a greenhouse at the University of Sulaimani–College of Agricultural Sciences Engineering. The results showed that seed germination percentage, shoot length, root length and number of leaves was significantly (p≤0.05) increased with both the treatments. Captan (0.5%) was more effective in comparison with Captan (0.3%) and seed germination, shoot length, root length and number of leaves was gradually increased with increase of the doses of fungicides. It can be suggested that fungicide Captan have antifungal effect and can be used to treat seed against seed borne pathogens of forest, increase seed germination and shoot length, root length and number of leaves.

scholarly journals Effects of different levels of NaCl on the seed germination of Cyamopsis tetragonoloba L.

2020 ◽  
Vol 49 (3) ◽  
pp. 625-632
Author(s):  
Muhammad Akram ◽  
Mehwish Zahid ◽  
Abu Bakr Umer Farooq ◽  
Muhammad Nafees ◽  
Atta Rasool
Keyword(s):  
Seed Germination ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Stress Index ◽  
Cyamopsis Tetragonoloba ◽  
Vigor Index ◽  
Seedling Length ◽  
Salinity Levels ◽  
Mean Germination Time ◽  
Different Levels

Effects of four different levels of NaCl (05, 10, 15, 20 dS/m) on the seed germination of cluster bean (Cyamopsis tetragonoloba L.) cultivars were investigated. Only distilled water was used in the control. The experiment was conducted in the Petri dishes under laboratory condition and laid out in CRD comprising five replicates. The results indicated that the germination index (GI), seed vigor index (SVI), germination stress index and seedling length (radicle and plumule) decreased with increase of salinity levels and germination percentage (GP) was reduced significantly at the highest level of salinity (200 mM). However, mean germination time (MGT) and time taken for 50% germination (T50) increased by increasing salinity levels. Correlation coefficient between all possible combinations was estimated and the results indicated that GP, GI, MGT, T50, and SVI had significant positive or negative correlation with each other.

scholarly journals Effect of PEG and mannitol to induce drought stress on seed quality and stand establishment in wheat (Triticum aestivum L.) genotypes

2021 ◽  
Vol 17 (2) ◽  
pp. 469-475
Author(s):  
S. B. Patil ◽  
Jitendra Kumar S. Hilli
Keyword(s):  
Triticum Aestivum ◽  
Drought Tolerance ◽  
Root Length ◽  
Seed Quality ◽  
Block Design ◽  
Triticum Aestivum L ◽  
Germination Percentage ◽  
Shoot Length ◽  
Seedling Vigour ◽  
Wheat Genotypes

An experiment was conducted to study the screening of wheat (Triticum aestivum L.) genotypes for drought tolerance under laboratory condition during2018 at Department of Seed Science and Technology, College of Agriculture, Vijayapura. The experiment was carried out in a factorial Complete Randomized Block Design with seven treatments replicated three times. Twenty six wheat genotypes were screened for drought tolerance using 0, 15, 30, 60 per cent polyethylene ethylene glycol 6000 (PEG6000) and 1, 2, 5 per cent mannitol solutions. Data were recorded on various seedling parameters like germination percentage, root length, shoot length, seedling dry weight and seedling vigour index. The seedling traits showed a decreasing trend in response to increased concentrations of PEG6000 and mannitol. Wheat genotype DBW-110 (98.70 %) and C-306 (92.50 %) were found to be the best genotype for screened based on germination percentage at 15 per cent PEG6000 and 5 per cent mannitol. Wheat genotypes HI-1620 (6.7 cm) and NIAW-3212 (4.5 cm) produced maximum root length, respectively at higher concentrations of PEG6000 and mannitol. The genotype HI-1620 (6.4 cm, @ 15 %; 5.4 cm, @ 5 % mannitol) showed maximum shoot length. The genotype HD-2733, DBW-14, DBW-88 showed highest reduction of seedling parameters observed at increase in osmotic stress condition.

Responses of Weedy Rice to Drought Stress at Germination and Seedling Stages

2013 ◽  
Vol 316-317 ◽  
pp. 451-459 ◽  
Author(s):  
Guo Hua Ding ◽  
Xiao Liang Liu ◽  
Dian Rong Ma ◽  
Xiao Xue Wang ◽  
Guang Yang ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Water Stress ◽  
Drought Stress ◽  
Root Length ◽  
Dry Weight ◽  
Shoot Length ◽  
Stress Index ◽  
Weedy Rice ◽  
Fresh Weight ◽  
Cultivated Rice

Drought is a world-spread problem seriously influencing grain production and quality, the loss of which is the total for other natural disasters, with increasing global climate change making the situation more serious. Rice is the staple food for more than 23% of world population, so rice anti-drought physiology study is of importance to rice production and biological breeding for the sake of coping with abiotic and biotic conditions. Much research is involved in this hot topic, but the pace of progress is not so large because of drought resistance being a multiple-gene-control quantitative character. On the other hand, stress adaptive mechanisms are quite different, with stress degree, time course, materials, soil quality status and experimental plots, thus increasing the complexity of the issue in question. Additionally, a little study is related to weedy rice.In order to investigate the effects of drought stress on germination and early seedling growth of weedy rice (Oryza sativa f. spontanea L.) and cultivated rice (Oryza sativa L.), polyethyleneglycol-6000 (PEG-6000) are used to generate -1.33MPa and 0MPa water stress in a laboratory condition (28±3°C). Complete randomized design with three replications is used in the study. After 10 days of germination, shoot length, the longest root length, root fresh weight, root dry weight, shoot fresh weight, shoot dry weight and root numbers are measured; germination percentage, and root to shoot ratio are calculated. Germination index (GI), shoot length stress index (SLSI), root length stress index (RLSI) and dry matter stress index (DMSI) are used to evaluate the response of different genotypes to PEG-induced water stress. Results of ANOVA analysis show that responses of weedy rice accessions and cultivated rice varieties to water stress are significant different, demonstrating the germplasm of weedy rice and cultivated rice are diverse which enables us to screen the germplasm tolerant to drought stress.

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