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Two salt-sensitive (Yongliang-15, GS-6058) and two salt-tolerant (JS-7, Xinchun-31) wheat cultivars were used to investigate the extension, extensibility (viscoelastic parameters), and chemical composition of the cell walls in their root elongation regions (apical 10 mm-long root segments), under salinity stress. The elasticity of the root cell wall, indicated by E0, significantly decreased in the salt-sensitive cultivars, whereas the E0 in the salt-tolerant cultivars was maintained at the same level as that in the non-saline condition. Root extension and the differences among cultivars were largely dependent on elastic extension, which accounts for one-half to two-thirds of the total extension. Viscosity, indicated by η0, and the plastic extension of the root cell walls did not change across the treatments and cultivars. The significant decrease in cell wall elasticity in the root elongation region was one of the factors that depressed root growth in salt-sensitive cultivars under the saline condition. The well-maintained elasticity of salt-tolerant cultivars alleviated the depression of root growth by NaCl. Cell wall elasticity was positively correlated with the relative pectin and hemicellulose I contents and negatively correlated with the relative cellulose content. Under saline conditions, the relative hemicellulose II content did not change in the salt-sensitive cultivars; however, it decreased in the salt-tolerant ones. Thus, changes in chemical composition of the cell wall were correspond with the cell wall extensibility and root growth in wheat cultivars with different degrees of salt tolerance.

Aim: To assess the pleiotropic role of a plant growth regulator, commercially identified as brassinolide (BR) in mitigating waterlogging stress imposed on maize. Study Design: A factorial combination of two maize varieties [Ikom White (IKW) and Oba-98], two BR levels (0 and 250 ml) and two waterlogging stages of maize growth [control (WL0) and seedling stage (WL1)], arranged as a split-split plot in a randomized complete block design with three replications was used. Place and Duration of Study: Akpabuyo Local Government Area, Cross River State-Nigeria. A two-year field experiment was conducted during the dry seasons of December 2016 and December 2017. Methodology: Waterlogging test was conducted on plots by demarcating them with 3.6 by 1.7 m metal sheets buried to a depth of 60 cm to prevent lateral soil-water movement. Two maize seeds were sown at 25 cm within and 75 cm between rows. The BR (250 ml) was sprayed foliar at 21 DAS. The non-waterlogging plots served as control. Observations were made on growth and yield variables as well as the plant's physiological traits. Results: Waterlogging significantly reduced the growth attributes of maize and increased (p≤0.05) the leaf moisture content. The photosynthetically active radiation on maize plants was substantially reduced (p≤0.05) by the waterlogging stress. Dry matter yield (DMY) and nutrient uptake in the leaves, stems and grains were reduced (p≤0.05) at both silking and at harvest. The effect of the BR was greater in Oba-98 with higher nutrient contents, radiation absorption, dry matter and grain yields than IKW. Conclusion: Treatment of maize plants with BR could induce some tolerance of field waterlogging. Thus, for optimum efficiency in maize production under stressed soil condition of waterlogging, it is recommended that the foliar spray of BR at the 250 ml per plant rate be considered.

Our aim was to assess if Brassinolide (BR) could ameliorate stress caused by waterlogging on maize. Two BR levels (with and without), two maize varieties [Ikom White (IKW) and Obatanpa-98 (Oba-98)]...

Our aim was to determine the combined effect of brassinolide (BR) and lime on the growth and yield of maize on acid soils of South East Nigeria using two BR levels (0 and 250 mL), two maize varieti...

Salinity episodes that are common in arid regions, characterized by dryland, are adversely affecting crop production worldwide. This study evaluated the effectiveness of brassinolide (BL) in ameliorating salinity stress imposed on soybean at four levels (control (1.10), 32.40, 60.60 and 86.30 mM/L NaCl) in factorial combination with six BL application frequency (control (BL0), application at seedling (BL1), flowering (BL2), podding (BL3), seedling + flowering (BL4) and seedling + flowering + podding (BL5)) stages. Plant growth attributes, seed yield, and N, P, K, Ca and Mg partitioning to leaves, stems and roots, as well as protein and seed-N concentrations, were significantly (p ≤ 0.05) reduced by salinity stress. These trends were ascribed to considerable impairments in the photosynthetic pigments, photosynthetically active radiation, leaf stomatal conductance and relative water content in the leaves of seedlings under stress. The activity of peroxidase and superoxidase significantly (p ≤ 0.05) increased with salinity. Foliar spray with BL significantly (p ≤ 0.05) improved the photosynthetic attributes, as well as nutrient partitioning, under stress, and alleviated ion toxicity by maintaining a favourable K+/Na+ ratio and decreasing oxidative damage. Foliar spray with brassinolide could sustain soybean growth and seed yield at salt concentrations up to 60.60 mM/L NaCl.

Our objective was to determine the combined effect of some plant growth regulators and nitrogen (N) on corn growth, yield and nitrogen use efficiency. A potted experiment was conducted with two levels of growth regulators [i.e. with or without treatment with Seed king (Kinetine), Root king (Indole-butyric acid) and More king (Chitosan)], two maize cultivars (Calabar White and Obatanpa-98 and three nitrogen rates (0, 90 and 180 kg/ha in the form of urea). The measured parameters were growth attributes, nitrogen uptake, dry matter yield, harvest-index, shoot to root ratio, yield attributes and agronomic and physiological nitrogen use efficiency. Calabar White had taller plants (154.53 cm) more leaves (12.00) and larger leaf area (466.98 cm2) than obatanpa-98 at 6 weeks after sowing. The dry matter yield of both leaf and stem increased significantly (P ≤ 0.05) with increasing N rates but the growth regulators significantly (P ≤ 0.05) increased only the leaf dry matter. The interaction between growth ...