Potassium (K) and magnesium (Mg) have a well-known antagonistic relationship in plants, but the idea that too much K can cause a “functional Mg deficiency” where Mg is present yet fails to support key processes has rarely been explored in relation to flower quality. K-induced functional Mg deficiency in the growing medium had a negative influence on N metabolism, photosynthesis, and vase life in gerbera, and these effects were partially ameliorated by increasing the Mg:K ratio. Two cultivars, ‘Stanza’ and ‘Double Dutch’, were treated with four nutrient solutions with different Mg:K ratios, i.e. 1:4, 1:2, 1:1 and 2:1. Tissue cation concentrations (K, Mg, and Ca), chlorophyll content (SPAD), flower yield and vase life were determined. A strong negative relationship between K and Mg was observed (r = −0.82 to −0.94). Under K-excess (Mg:K 1:4), tissue Mg did not drop critically, yet plants showed clear stress: chlorophyll declined to 50.9 SPAD, vase life shortened to 15 days, and flower production dropped to 7.2 per plant. Nitrogen assimilation was also impaired. In contrast, all the parameters were dramatically improved when the Mg:K ratio was adjusted to 1:1, i.e., chlorophyll was 58.7 SPAD, vase life was 18.5 d, and flower yield was 9.2 pls. These results demonstrate that K-induced functional Mg deficiency may compromise postharvest quality by altering N metabolism and photosynthesis. Recovery of the Mg:K balance to 1:1 reverses these deficits, providing a mechanistically-based practical solution for genotype specific nutrition management in gerbera production.
Diverse genetic resources play a significant role in Ethiopian traditional medicine across the cultures of various nations. However, overexploitation leads to a decline in the population of important medicinal plant species. Echinops kebericho is a popular medicinal plant, that is currently critically endangered. Understanding the genetic diversity of kebericho plants is important for recommending strategies for conservation, improvement, and sustainable utilization. Thus, the present study of genetic diversity was caried out using 1925 DArTseq SNP markers for the 60 accessions of kebericho plant collected from 36 different geographical locations of Ethiopia. The SNP markers had gene diversity (0.26) and polymorphic information content (0.22). The result of genetic diversity indices (I = 0.43, Ho = 0.05, He = 0.28, F = 0.78, and PPL = 90.60
Allelopathy refers to chemically mediated interactions in which compounds released by donor plants alter the performance of neighboring plants, and it can influence community assembly, environmental filtering, and crop–weed dynamics. These effects arise through root exudation, volatilization, foliar leaching, and residue decomposition, and are modified by soil sorption, abiotic transformation, and microbial biotransformation. Evidence from invasion ecology is consistent with the Novel Weapons Hypothesis in some systems, but the magnitude of allelopathic effects varies strongly with donor–receiver identity, evolutionary history, dose, exposure duration, and environmental context. Importantly, chemically mediated plant–plant interactions should not be reduced to phytotoxicity alone: direct inhibitory effects must be distinguished from chemical perception and recognition, in which low or sublethal concentrations can function as informational cues. Natural effects may also reflect additive or synergistic activity among multiple metabolites rather than a single compound. In agriculture, these mechanisms provide opportunities for weed-suppressive crops, residues, cover crops, and bioherbicide discovery, but field-scale translation remains constrained by uncertainty about environmentally realistic exposure and bioavailable concentrations. This review therefore integrates release pathways, soil fate, physiological and oxidative mechanisms, plant–soil feedbacks, evolutionary context, and methodological limitations within a unified framework. We argue that future progress depends on experiments that separate chemical interference from resource competition and physical residue effects, quantify bioavailable allelochemicals in situ, and incorporate microbial and spatiotemporal dynamics. Such evidence would strengthen efforts to translate allelopathic potential into reliable components of sustainable weed management and resilient agroecosystem design.
Plant-derived extracts have emerged as multifunctional biostimulants that enhance plant growth, productivity, and resilience under diverse abiotic and biotic stresses. This review synthesizes current knowledge on the sources, phytochemical composition, mechanisms of action, application modes, and agronomic outcomes of plant and macroalgal extracts in crop systems. Particular emphasis is placed on their complex biochemical composition, including phytohormone-like compounds, antioxidants, osmoprotectants, phenolics, oligosaccharides, fatty acids, and proteins/peptides, which collectively regulate plant metabolism rather than acting through single active constituents. Mechanistic evidence indicates that these extracts modulate hormone-mediated signaling pathways (ABA, SA, JA, and ET), activate stress-responsive genes, enhance osmolyte accumulation, strengthen antioxidant defenses, restore ionic homeostasis, and regulate water transport through aquaporin activity. In addition, they influence rhizosphere interactions and microbiome dynamics, thereby improving nutrient acquisition and systemic plant resilience. Emerging advances also highlight the integration of nanotechnology in plant-derived biostimulants, where plant-mediated nanoparticles and nano-formulations improve the stability, delivery efficiency, and bioavailability of bioactive phytochemicals. These nano-enabled approaches have demonstrated potential to enhance seed germination, physiological performance, and crop productivity under environmental stress. Case studies involving drought, salinity, heat, cold, and biotic stresses consistently report improvements in photosynthetic stability, stress tolerance, and yield under optimized application strategies. Future research integrating multi-omics, microbiome profiling, and precision nanotechnology will be essential to maximize the sustainable potential of plant extract (PE) -based biostimulants in modern agriculture.
Although a considerable amount of literature on the karyological characteristics of Arachis is available, no detailed study has been conducted to elucidate the cytogenetic relationships among its taxa. Thus, the current study aimed to inspect the level and tendency of chromosome diversity in this genus. The karyo-morphological characteristics of 86 taxa (309 accessions) representing nine sections of Arachis and the reference genus, Stylosanthes, were obtained through an intensive literature survey. The karyological parameters included the total haploid chromosome length (THL), somatic chromosome number (2n), and basic chromosome number (x), along with several karyotype asymmetry indices (like CVCL, CVCI, MCA, A₁, A₂, AsK
