Molecular characterization of bread wheat (Triticum aestivum) genotypes using SSR markers

An experiment was conducted during winter (rabi) seasons of 2019–20 and 2020–21 at the research farm of CCS Haryana Agricultural University to study the genetic diversity of 80 bread wheat (Triticum aestivum L.) genotypes, using 43 polymorphic SSR markers. A total of 84 alleles were discovered, with an average of 3 alleles amplified per locus. The average value of the allelic PIC varied from 0.26 to 0.82. Primers, viz. Xgwm 129, Xgwm 131, TaGST, CFA2147, Xwmc48, Xbarc 1165 and Xwmc169 may be deemed particularly informative given their high PIC values. Indices of dissimilarity varied from 0.14 to 0.42. Eighty wheat genotypes were clustered into two main groups with 35 and 45 genotypes each using the dendrogram constructed on the basis of molecular data of polymorphic markers. Using STRUCTURE, genotypes were classified into 4 major sub-populations having Fst values 0.351, 0.363, 0.508 and 0.313, respectively. Future breeding operations in wheat cultivars for tolerance to abiotic stress should consider genotypes clustering into different groups. Assessing the molecular genetic diversity is a reliable approach to identify cultivars by analyzing of specific regions of the cultivars DNA based on their unique genetic profiles

Role of Salicylic Acid in Combating Heat Stress in Plants : Insights into Modulation of Vital Processes

Peer reviewe

Efficacious role of silica nanoparticles in improving growth and yield of wheat under drought stress through stress-gene upregulation

Climate change is now evident and severe water shortage due to unpredictable raining season along with extended summers is expected to hamper crop production across the globe. Application of nanoparticle based formulations is one of the most sought after approach that is being explored currently to alleviate drought stress impact on plants. The present study was aimed to evaluate the potential of biosynthesized silica nanoparticles (silica NPs) in improving the drought tolerance of wheat. Four different concentrations of silica NPs (30, 60, 90, and 120 ppm) were used to treat wheat plants grown under two irrigation regimes- 50% soil moisture content (drought) and 100% soil moisture content (well-watered). The induced drought caused a prominent reduction in both - the crop yield and the morphological parameters of the crop. Foliar application of silica NPs at all concentrations, increased the plant's tolerance towards water stress but 60 ppm concentration was found to be most effective amongst all. After treatment with silica NPs at 60 ppm concentration, the plant height increased by 8.28%, spikes per plant by 98%, seeds per spike by 12.4%, and thousand seed weight by 37.5% as compared to the control. Besides this, expression levels of four drought-stress responsive genes-ABC1, Wdhn13, CHP, and EXP2 was also studied. We observed an enhanced expression of all the stress genes after treatment with silica nanoparticles in wheat plants grown under water deficient conditions, clearly supporting the influence of NP treatment at gene/molecular level. In nutshell, we conclude that silica nanoparticles have the potential to significantly ameliorate the negative impact of drought stress by reviving plant growth and modulating gene expression

Enhancing Gerbera Micropropagation Efficiency and Genetic Fidelity through Cytokinin and Auxin Combination Strategies

The present investigation was carried out to assess the impact of 6-benzyladenine (BA) in conjunction with Indole-3-butyric acid (IBA) on gerbera explant establishment under micropropagation. Additionally, the effects of BA, either individually or in combination with Kinetin (KIN), on shoot proliferation in two Gerbera cultivars, namely Kormoran and Dolores was experimented too. Throughout the experiment, various morphological changes were documented occurring during these micropropagation phases and also monitored potential genetic alterations using SSR markers. The studies revealed that the combination of BA and IBA yielded exceptional results, achieving a 100% success rate in explant regeneration within the shortest time frame. Notably, when BA and IBA were applied at lower concentrations, the number of shoots generated was reduced. However, the most substantial proliferation of shoots was observed when the growth medium contained 4 mg of BA and 0.5 mg of IBA per litre. Furthermore, our investigation into genetic fidelity using SSR analysis revealed no detectable polymorphism between the mother plant and the micropropagated plantlets in both the Gerbera cultivars, affirming the reliability of the micropropagation method in preserving genetic consistency

Heat stress tolerance indices for identification of the heat tolerant wheat genotypes

Abstract Heat stress is one of the major challenges in wheat cultivation because it coincides with the flowering period and limits the crop productivity. This study was conducted for evaluation of 50 wheat genotypes to identify the heat stress tolerant genotypes for improvement of stress tolerance. All genotypes were cultivated for two consecutive years (2018–2020) under normal and late sown conditions. The results of the study revealed that the combined analysis of variance indicated significant variations among genotypes for all the studied stress indices. The reduction in mean grain yield of all genotypes under stress condition as compared to non-stress condition, indicating that the heat stress significantly affect the grain yield. The correlation analysis showed that the negative correlation of tolerance index and stress susceptibility percentage index with the grain yield of genotypes under heat stress condition (Ys) and a highly positive correlation of stress tolerance index, mean productivity, geometric mean, harmonic mean and mean relative performance with grain yield (Yp and Ys) under both conditions, helped accurately to identify the desirable genotypes. From the results obtained from principal component, biplot and cluster analysis, it was reported that HD 2967, WH 1249, HI 1617, WH 1202, WH 1021 and WH 1142 are suitable and good yielding genotypes under both conditions. Thus, above genotypes can be used for cultivation at high temperature or as genetic resources for introducing genetic variations in wheat genotypes to improve stress tolerance

Development and Evaluation of Bacteriophage Cocktail to Eradicate Biofilms Formed by an Extensively Drug-Resistant (XDR) <i>Pseudomonas aeruginosa</i>

Extensive and multiple drug resistance in P. aeruginosa combined with the formation of biofilms is responsible for its high persistence in nosocomial infections. A sequential method to devise a suitable phage cocktail with a broad host range and high lytic efficiency against a biofilm forming XDR P. aeruginosa strain is presented here. Out of a total thirteen phages isolated against P. aeruginosa, five were selected on the basis of their high lytic spectra assessed using spot assay and productivity by efficiency of plating assay. Phages, after selection, were tested individually and in combinations of two-, three-, four-, and five-phage cocktails using liquid infection model. Out of total 22 combinations tested, the cocktail comprising four phages viz. φPA170, φPA172, φPA177, and φPA180 significantly inhibited the bacterial growth in liquid infection model (p 10 times than the individual dose in the inhibition of XDR P. aeruginosa host. Field emission-scanning electron microscopy was used to visualize phage cocktail mediated eradication of 4-day-old multi-layers of XDR P. aeruginosa biofilms from urinary catheters and glass cover slips, and was confirmed by absence of any viable cells. Differential bacterial inhibition was observed with different phage combinations where multiple phages were found to enhance the cocktail’s lytic range, but the addition of too many phages reduced the overall inhibition. This study elaborates an effective and sequential method for the preparation of a phage cocktail and evaluates its antimicrobial potential against biofilm forming XDR strains of P. aeruginosa

Mitigation of lead toxicity in Brassica juncea L. by sulphur application – Via various biochemical and transcriptomic strategies

The present study was designed to elucidate whether exogenously applied sulphur (S) (S1; 100 ppm, S2; 200 ppm S) alleviate lead (Pb)-induced (Pb1; 100 ppm, Pb2; 200 ppm and Pb3; 300 ppm Pb) stress in the leaves of Brassica juncea. To study this effect, oxidative stress biomarkers (hydrogen peroxide and malondialdehyde), enzymatic antioxidants (ascorbate peroxidase (APX), glutathione reductase (GR)), non-enzymatic antioxidants (chlorophyll and carotenoids) and S-metabolic enzymes like adenosine triphosphate sulfurylase (ATPS), O-acetylserine(thiol)lyase (OASTL) were studied. Pb treatment dramatically inhibited plant development by increasing lipid peroxidation and hydrogen peroxide (H2O2) accumulation by 34.82 and 238.89 % respectively at 90 days plant. The overproduced oxidative biomarkers alter plant cell homeostasis. In contrast, APX (25.56 %) and GR (32.45 %) activities, chlorophyll (15.51 %) and carotenoids (30 %) contents increased under similar Pb treatments and regulated ROS-antioxidant balance. Exogenous S application, maintained the redox status of cell by further increasing the enzymatic activities. Pb treatment increased S assimilation in Brassica by elevating enzyme activities of ATPS and OASTL, which was further augmented by S supplementation to Pb-stressed plants. Besides gene expression of BjSULT, BjOASTL and BjGR1 exhibited slight increase under Pb stress, S application to the stressed plants doubled the expression and assisted the stress resistance. Overall, our findings demonstrate that S protect Pb-stressed Brassica seedlings, implying that S could be an ideal choice for reducing Pb toxicity in crops

Impact of High Temperature on Germination, Seedling Growth and Enzymatic Activity of Wheat

Global warming has increased the temperature significantly over a large extent both spatially and temporally. The threat of heat stress during the germination and seedling establishment stages in the wheat crop is now more prevalent than ever before. The present experiment assessed the effect of elevated temperature on the germination and early seedling growth of wheat genotypes. The seeds were sown under four temperatures, viz., 20 °C, 25 °C, 30 °C and 35 °C; the germination, seedling vigor and enzyme activities in 8-day-old seedlings were assessed. The temperature significantly influenced germination and early seedling growth. The germination percentage at 20 and 25 °C was statistically on par with and higher than at 30 and 35 °C. The seedling vigor parameters were maximum at 25 °C and showed a reduction at higher temperatures. Genotypic differences were observed for early heat stress as the genotypes WH 730, WH 1123 and HD 2967 showed tolerance towards heat stress during germination, whereas the genotypes PBW 725 and WH 1105 were susceptible. Antioxidant enzyme activities in seedlings increased with the rise in temperature. Catalase, peroxidase and superoxide dismutase enzymes showed increased activities at higher temperature levels

Interactive effects of water volume and soaking duration of hydropriming on germination characteristics of wheat seed.

Interactive effects of water volume and soaking duration of hydropriming on germination characteristics of wheat seed.</p

Interactive effect of genotype and water volume of hydropriming on root length, seedling length, seedling biomass and seedling vigour index-I of wheat.

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