Search Results (6)

Syzygium oleosum (F.Muell.) B.Hyland is an Australian native species whose essential oil (EO), known commercially as “Mango Myrtle,” is gaining popularity in aromatherapy, yet remains poorly studied. This work provides the first comprehensive pharmacognostic investigation of S. oleosum. Anatomical and micromorphological analyses revealed numerous secretory cavities and calcium oxalate druses in both leaves and twigs. GC-MS analysis identified 16 components in the EO, predominantly hydrocarbon monoterpenes, with terpinolene (30.79%), β-pinene (26.79%), α-pinene (10.69%), and γ-terpinene (9.86%) as major constituents. In vitro assays showed moderate antioxidants (IC₅₀ ≤ 4.95 mg/mL) and anti-inflammatory effects (IC₅₀ ≤ 5.93 mg/mL), with specific monoterpenes contributing differentially to each activity. The EO displayed weak inhibitory activity against acetylcholinesterase (IC₅₀ 19.4 mg/mL) and butyrylcholinesterase (IC₅₀ 15.9 mg/mL), and no effect on GABA transaminase. Microelectrode array recordings on primary cortical neurons demonstrated a concentration-dependent inhibition of network activity (0.059–1.19 mg/mL) without affecting cell viability, indicating a neuromodulatory property. These results provide new insights into the pharmacological potential of S. oleosum EO and support its further evaluation as a neuroactive and anti-inflammatory agent. Full article

Mineral nutrition is essential for plant growth and the interaction of plants with biotic and abiotic stresses. Mango twig-tip dieback (MTTD) is a new type of mango decline, but its impact on trees’ mineral nutrition is unknown. This study was conducted to determine the effect of MTTD infection on the nutrient status, balance, and resorption efficiency (RE) of mangoes. Leaf nutrient concentrations and deviation from the optimum percentage (DOP) indices of ‘Kensington Pride’ (KP) mango trees with low (LD) and high (HD) levels of MTTD infections were analyzed to compare the foliar nutrition status and nutrient balance between the LD and HD trees. Moreover, the nutrient resorption efficiency of MTTD-infected dried leaves (RE_D) was compared with the resorption efficiency of healthy (RE_S) leaves of KP mangoes. The concentrations of total Ca, Mg, Cu, Fe, Mn, and Zn were lower in the HD trees than in the LD trees. But the total K content was higher in the HD trees, and its DOP index was sufficient, while the total K concentration was of a low and deficient level in LD trees. Moreover, the DOP indices for total Ca, Mn, and Zn were less deficient in LD trees than in HD trees, and the overall nutrient imbalances were exacerbated in HD trees. The RE_D was significantly lower than RE_S for the total N, P, S, Cu, Fe, and Zn but significantly higher than RE_S for K. This study underscores the significant influence of MTTD on the mineral nutrition of KP mangoes, revealing distinct nutrient variations between trees with low and high MTTD infection levels. These findings have important implications for mango crop management, emphasizing the need for targeted nutrient interventions to address imbalances induced by MTTD and enhance the overall health and resistance of mango trees against MTTD infections. Full article

Volatile organic compounds (VOCs), as a biological element released from plants, have been correlated with disease status. Although analysis of VOCs using GC-MS is a routine procedure, it has limitations, including being time-consuming, laboratory-based, and requiring specialist training. Electronic nose devices (E-nose) provide a portable and rapid alternative. This is the first pilot study exploring three types of commercially available E-nose to assess how accurately they could detect mango twig tip dieback and Panama disease in bananas. The devices were initially trained and validated on known volatiles, then pure cultures of Pantoea sp., Staphylococcus sp., and Fusarium odoratissimum, and finally, on infected and healthy mango leaves and field-collected, infected banana pseudo-stems. The experiments were repeated three times with six replicates for each host-pathogen pair. The variation between healthy and infected host materials was evaluated using inbuilt data analysis methods, mainly by principal component analysis (PCA) and cross-validation. GC-MS analysis was conducted contemporaneously and identified an 80% similarity between healthy and infected plant material. The portable C 320 was 100% successful in discriminating known volatiles but had a low capability in differentiating healthy and infected plant substrates. The advanced devices (PEN 3/MSEM 160) successfully detected healthy and diseased samples with a high variance. The results suggest that E-noses are more sensitive and accurate in detecting changes of VOCs between healthy and infected plants compared to headspace GC-MS. The study was conducted in controlled laboratory conditions, as E-noses are highly sensitive to surrounding volatiles. Full article

The white mango scale (WMS) insect, Aulacaspis tubercularis (Hemiptera: Diaspididae), is a polyphagous, multivoltine pest which is a serious threat to qualitative mango production and export. The WMS insect sucks sap from leaves, branches and fruits. The heavy infestation of this pest may cause the falling of young leaves, drying up of twigs, poor flowering, and, finally, reduce the quality of fruits by producing pink spots on fruits’ surface. This review paper was written to provide comprehensive information about pest biology, ecology and management in different parts of the world. WMS was first reported on the island of Formosa on Mangifera indica in 1929 and later on in the Caribbean Islands, India and Brazil. Now it is found in almost 69 mango-producing countries of the world. The thermal regime may affect the population of pests. In Australia, the life cycle is completed in 35–40 days in summer and 70–85 days in winter. Variety, age of plants, number of trees per acre, canopy size and sunlight penetration affect the density of WMS. Different Coccinellid beetles and parasitoid Encarsia femorosa feed on WMS; however, farmers most commonly use insecticides to get rid of this pest. In Pakistan, WMS is a growing threat to the export of mangoes; hence IPM plan is needed to reduce the pest numbers and enhance qualitative mango production. Full article

Mango is one of the main fruits grown in Mexico that are exported worldwide, but the trees consume a lot of water, and irrigation scheduling should be implemented to optimize water use. Dendrometers were installed in fruit trees to optimize water usage during 2019 and 2020. A capacitor with Teflon clamps pressurized the leaf, and its dielectric changed with leaf water content. Additionally, Hall sensors were installed in leaves to study the effect of water during mango production. It was found that capacitance tend to be more sensitive than magnetic field monitoring. Higher changes were noted during midday with warm weather. Thresholds from the capacitance and Hall effect sensors can provide signals for irrigation scheduling. Full article

Mango is affected by different decline disorders causing significant losses to mango growers. In the United Arab Emirates (UAE), the pathogen was isolated from all tissues sampled from diseased trees affected by Lasiodiplodia theobromae. Symptoms at early stages of the disease included general wilting appearance of mango trees, and dieback of twigs. In advanced stages, the disease symptoms were also characterized by the curling and drying of leaves, leading to complete defoliation of the tree and discolouration of vascular regions of the stems and branches. To substantially reduce the devastating impact of dieback disease on mango, the fungus was first identified based on its morphological and cultural characteristics. Target regions of 5.8S rRNA (ITS) and elongation factor 1-α (EF1-α) genes of the pathogen were amplified and sequenced. We also found that the systemic chemical fungicides, Score^®, Cidely^® Top, and Penthiopyrad^®, significantly inhibited the mycelial growth of L. theobromae both in vitro and in the greenhouse. Cidely^® Top proved to be a highly effective fungicide against L. theobromae dieback disease also under field conditions. Altogether, the morphology of the fruiting structures, molecular identification and pathogenicity tests confirm that the causal agent of the mango dieback disease in the UAE is L. theobromae. Full article