Because pineapple is an important crop in Vietnam, it is crucial to assess the nutrition status of the pineapple. Although the diagnosis and recommendation integrated system (DRIS) is a reliable approach, finding the right leaf position to diagnose is vital. Therefore, the aim of the current study is to determine suitable leaf positions for creating DRIS norms for macro- and micronutrients in pineapple leaf. Healthy pineapple leaves without pest or disease damages were sampled from 60 pineapple farms and analyzed for N, P, K, Na, Ca, Mg, Cu, Fe, Zn, and Mn concentrations. The results revealed that the critical yield was 13.3 t ha-1 among the 60 farms, dividing into 23 farms as the high-yielding group (>= 13.3 t ha(-1)) and 37 farms as the low-yielding group (< 13.3 t ha(-1)). The concentrations of mineral nutrients (N, P, K, Ca, Mg, Cu and Zn) and pineapple fruit yields in the high-yielding group were greater than those in the low-yielding one. On the other hand, the Na, Fe, and Mn concentrations showed the opposite pattern. Selected leaf positions must possess significantly different nutrient ratios and have more than 14 nutrient ratio pairs between the two yield groups. Therefore, leaf positions from +15 to +19 were selected to create DRIS norms. Nine sets of DRIS norms have been created at leaf +1, +3, +7, +9, +16, +18, +21, +22, and +29 for plant pineapples.

BackgroundCadmium (Cd) is one of the most important stress factors in plants, with its high mobility in soils, ease of uptake by plants and toxicity at low concentrations. Aluminum (Al) is another phytotoxic metal, the accumulation of which is a crucial agricultural complication for plants, especially in acidic soils. Methods and resultsIn this study, Bryophyllum daigremontianum clone plantlets were obtained from bulbiferous spurs of a mother plant and separated into four different groups and watered with Hoagland solution and mixtures containing 0, 50, 100, and 200 mu M of AlCl3 and CdCl2 each for 75 days. Control groups were maintained under the same conditions without Al and Cd treatment. To simulate acidic soil conditions typical of environments where Al toxicity is prevalent, the soil pH was adjusted to 4.5 by spraying the sulphuric acid (0.2%) with 2-day intervals after each irrigation day. After harvesting, growth parameters such as shoot length and thickness, root, shoot and leaf fresh and dry weights were measured, along with physiological parameters like mineral nutrient status, total protein, and photosynthetic pigment concentrations (chlorophyll a, b, a/b, total chlorophyll, and carotenoid) in both control and experimental groups of B. daigremontianum clones. In response to Al and Cd applications, the plant height, shoot thickness and carotenoid levels were declined, whereas the increments were found in leaf/shoot/root fresh weight, root dry weight, and total protein content. Moreover, differences in genomic alterations were investigated using 21 ISSR and 19 RAPD markers, which both have been used extensively as genetic markers to specify phylogenetic relationships among different cultivars as well as stress-dependent genetic alterations. RAPD primers were used due to their arbitrary sequences and the unknown genome sequence of the plant material used. In contrast, ISSR primers were preferred for a genome-wide genotoxic effect scan via non-arbitrary and more common genetic markers. Distinct types of band polymorphisms detected via RAPD and ISSR markers include band loss, and new band formation under a combination of Al and Cd stress. 17 ISSR and 14 RAPD primers generated clear electrophoretic bands. ConclusionThe study revealed that combined application of Al and Cd affect B. daigremontianum clones in terms of growth, physiology and genotoxicity related to the increasing concentrations.

Nanotechnology represents an innovative approach to ameliorating abiotic stress in oilseed crops, with the application of iron oxide nanoparticles (FeO-NPs) gaining notable popularity recently. Therefore, we have utilized FeO-NPs as an alleviating agent on an oilseed crop, specifically rapeseed (Brassica napus L.), grown in soil with varying levels of arsenic (As). This study investigates various growth-related attributes, the efficiency of the photosynthetic machinery, indicators of oxidative stress, and responses of both enzymatic and non-enzymatic antioxidants, along with their specific gene expression, sugar content, organic acids exudation pattern and As accumulation in different parts of the plant. Our findings indicated that soil contaminated with As reduced crop growth, photosynthetic efficiency, and nutritional status in plants, while simultaneously enhancing oxidative stress indicators, organic acid exudation, activity of both enzymatic and non-enzymatic antioxidants and their related gene expressions, and endogenous As content in the shoots and roots of B. napus. Moreover, increasing levels of As in the soil caused a signifcant increase in proline and organic acids exudation pattern. However, the exogenous application of FeO-NPs enhanced plant growth and the photosynthetic rate in B. napus by boosting the antioxidant system and mineral status, and by reducing the concentrations of oxidative stress biomarkers, organic acids, and As accumulation in both roots and shoots. Hence, this study suggests that seed priming with FeO-NPs is an effective technique that can be employed to fortify nutrients and mitigate metal toxicity in areas polluted with metals.

Although zinc (Zn) is a micronutrient, excessive amounts in the soil can have toxic effects on plants. Fertilizers, limestone materials, pesticides, and fungicides added with Zn have contributed to increasing the concentration of this element in agricultural soils. Accordingly, it is necessary to find Zn-tolerant plant species to be properly used in degraded soil restoration programs. Thus, the current study aims to investigate the influence of different Zn concentrations on photosynthetic variables, antioxidant activity, and growth of I. marginata and A. edulis seedlings to determine their potential to be used as phytoremediation species. The experiment was installed in a 2x5 factorial scheme, with the first factor being two species ( Allophylus edulis and Inga marginata ), and the second factor: five concentrations of Zn (2, 75, 150, 225, and 300 mu M), with three replications per treatment. Each sampling unit consisted of a pot with five plants. Photosynthetic, morphological variables of the shoot and root systems, chlorophyll a fluorescence, photosynthetic pigments, antioxidant enzyme activity, lipid peroxidation, hydrogen peroxide concentration, and Zn accumulated in the roots and shoot were evaluated. Zn stress has activated an efficient antioxidant system, which reduced oxidative damage in the leaves of both species; consequently, it did not decrease shoot biomass production in Inga marginata and Allophylus edulis seedlings. High Zn accumulation in plant tissues and lack of negative effects on Inga marginata and Allophylus edulis shoot have suggested that these plant species are tolerant to Zn and may be indicated for Zn-polluted soil phytoremediation purposes.