Evaluation of growth and nutritional value of Brassica microgreens grown under red, blue and green LEDs combinations.

Microgreens are rich functional crops with valuable nutritional elements that have health benefits when used as food supplements. Growth characterization, nutritional composition profile of 21 varieties representing five species of the Brassica genus as microgreens were assessed under light-emitting diodes (LEDs) conditions. Microgreens were grown under four different LEDs ratios (%); red:blue 80:20 and 20:80 (R80 :B20 and R20 :B80 ), or red:green:blue 70:10:20 and 20:10:70 (R70 :G10 :B20 and R20 :G10 :B70 ). Results indicated that supplemental lighting with green LEDs (R70 :G10 :B20 ) enhanced vegetative growth and morphology, while blue LEDs (R20 :B80 ) increased the mineral and vitamin contents. Interestingly, by linking the nutritional content with the growth yield to define the optimal LEDs setup, we found that the best lighting to promote the microgreen growth was the green LEDs combination (R70 :G10 :B20 ). Remarkably, under the green LEDs combination (R70 :G10 :B20 ) conditions, the microgreens of Kohlrabi purple, Cabbage red, Broccoli, Kale Tucsan, Komatsuna red, Tatsoi and Cabbage green, which can benefit human health in conditions with limited food, had the highest growth and nutritional content.

Biological Control of Tomato Bacterial Leaf Spots and Its Impact on Some Antioxidant Enzymes, Phenolic Compounds, and Pigment Content.

Tomato bacterial spots, caused by Xanthomonas campestris pv. vesicatoria (Xcv1) and X. euvesicatoria (Xe2), as well as bacterial specks, caused by two strains of Pseudomonas syringae pv. tomato (Pst1 and Pst2), represent significant threats to tomato production in the El-Sharkia governorate, often resulting in substantial yield losses. The objective of this study was to evaluate the efficacy of various biocontrol culture filtrates, including bacteria and fungi agents, in managing the occurrence and severity of these diseases, while also monitoring physiological changes in tomato leaves, including antioxidant enzymes, phenolics, and pigment content. The culture filtrates from examined Trichoderma species (T. viride, T. harzianum, and T. album), as well as the tested bacteria (Bacillus subtilis, Pseudomonas fluorescens, and Serratia marcescens) at concentrations of 25%, 50%, and 100%, significantly inhibited the proliferation of pathogenic bacteria In vitro. For the In vivo experiments, we used specific doses of 5 mL of spore suspension per plant for the fungal bioagents at a concentration of 2.5 × 107 spores/mL. The bacterial bioagents were applied as a 10 mL suspension per plant at a concentration of 1 × 108 CFU/mL. Spraying the culture filtrates of the tested bioagents two days before infection In vivo significantly reduced disease incidence and severity. Trichoderma viride exhibited the highest efficacy among the fungal bioagents, followed by T. harzianum and T. album. Meanwhile, the culture filtrate of B. subtilis emerged as the most potent among the bacterial bioagents, followed by P. fluorescens. Furthermore, applying these culture filtrates resulted in elevated levels of chitinase, peroxidase, and polyphenol oxidase activity. This effect extended to increased phenol contents, as well as chlorophyll a, chlorophyll b, and carotenoids in sprayed tomato plants compared to the control treatment. Overall, these findings underscore the potential of these biocontrol strategies to effectively mitigate disease incidence and severity while enhancing plant defense mechanisms and physiological parameters, thus offering promising avenues for sustainable disease management in tomato production.

Bactericidal activity of some plant essential oils against Ralstonia solanacearum infection.

Potato plants and their tubers in Egypt are affected by one of the most renowned soil-borne pathogen, Ralstonia solanacearum, that caused brown rot in potato tubers and wilt in plants. There is no efficient therapeutic bactericide so; control of bacterial wilt is very rough. The study investigated three different concentrations of seven essential plant oils under in vitro and in vivo conditions as a result of their effects on Ralstonia solanacearum growth and their possibility use as potato seed pieces dressing for controlling bacterial wilt disease incidence. In vitro, anise oil at the three tested different concentrations (0.04, 0.07, and 0.14% vol/vol) was the most effective one inhibiting the growth of T4 and W9 isolates of Ralstonia solanacearum then pursued by thyme, lemongrass, and clove oils. On the other hand, rocket oil at the tested concentration was the least effective one followed by fennel oil. However, wheat germ oil was not completely effective. In vivo, experiment revealed that anise oil at the three concentrations significantly reduced disease incidence and severity in sponta and hermes potato cultivars and their effect was associated with increase of peroxidase, polyphenoloxidase, phenols and the foliar fresh weight of treated plants as well as the weight of tubers/plant followed by thyme and lemongrass oils compared to the infected untreated control. Morphological differences in bacterial cell structure have been observed using a transmission electron microscope (TEM). Anise oil at higher concentration caused of cell wall rupture and degraded cellular components.

Detecting pathogenic bacterial wilt disease of potato using biochemical markers and evaluate resistant in some cultivars.

Bacterial wilt caused by Ralstonia solanacearum (Smith), is one of the chief severe diseases of potato in warm temperate regions, tropics and subtropics of the world. The study was conducted to isolate and identify bacterial pathogens and select the most resistant cultivars and avoid the decrease in the total value of Egyptian potato exports to the European Union (EU) due to the quarantine restrictions imposed by the EU on potato tubers exported from Egypt affected by bacterial wilt. The results of traditional identification through morphological and serological studies showed that the five isolates were isolated and identified as Ralstonia solanacearum. Furthermore, the results illustrated that RS5 isolate showed the lowest percentage of disease incidence reduction on the three tested potatoes cultivar Bellini, Spunta and Mondial recorded 9.64%, 15.41% and 34.12%, respectively. While, RS8 isolate exhibited the highest effective one the percentage of disease reduction on all tested potato cultivars. This isolate reduced disease incidence 60.60%, 63.21% and 71.66%, compering to the healthy control treatment. The result of molecular identification represent that the probe used in Taq-man (PCR) was of the type (B2) capable to detect only biovar 2 of R. solanacearum bacterial wilt. Furthermore, primer and probe are specific for detection of the race 3 biovar 2 strain. Positive results were obtained in all assays used including IFAS, protein content and SDS-PAGE with all five isolates. So the isolate (RS5) was the most virulence one, followed by RS1, RS3, RS2 and RS8, registered that the tested isolates were R. solanacearum race 3, biovar 2. Also, studies focused on the form of genetic distances and similarities based on pathogenic and plant growth parameters. The results illustrate that the highest genetic similarity (0.998) was found between Bellini and Spunta cultivars as the closest but the lowest value (0.946) was found between Mondial and Bellini as most distant. These results were similarity with genetic distances and SDS-PAGE profile of the three tested potato cultivars.