Although the effect of folic acid (FA) and its derivatives (folates) have been extensively studied in humans and animals, their effects are still unclear in most plant species, specifically under various abiotic stress conditions. Here, the impact of FA as a foliar application at 0, 0.1, and 0.2 mM was studied on snap bean seedlings grown under non-saline and salinity stress (50 mM NaCl) conditions. The results indicated that under salinity stress, FA-treated plants revealed a significant (p ≤ 0.05) increase in growth parameters (fresh and dry weight of shoot and root). A similar trend was observed in chlorophyll (Chl b), total chlorophyll, carotenoids, leaf relative water content (RWC), proline, free amino acids (FAA), soluble sugars, cell membrane stability index (CMSI), and K, Ca, and K/Na ratio compared to the untreated plants. In contrast, a significant decrease was observed in Na and salinity-induced oxidative damage as indicated by reduced H₂O₂ production (using biochemical and histochemical detection methods) and rate of lipid peroxidation (malondialdehyde; MDA). This enhancement was correlated by increasing the activities of antioxidant enzymes, i.e., superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (G-POX), and ascorbate peroxidase (APX). Gene expression analyses conducted using qRT-PCR demonstrated that genes coding for the Na⁺/H⁺ antiporter protein Salt Overly Sensitive 1 (SOS1), the tonoplast-localized Na⁺/H⁺ antiporter protein (NHX1), and the multifunctional osmotic protective protein (Osmotin) were significantly up-regulated in the FA-treated plants under both saline and non-saline treatments. Generally, treatment with 0.2 mM FA was more potent than 0.1 mM and can be recommended to improve snap bean tolerance to salinity stress.

Assessment of Genetic Diversity and Relationships among Egyptian Mango (Mangifera indica L.) Cultivers Grown in Suez Canal and Sinai Region Using RAPD Markers

Salvadora persica L. is a medicinal plant distributed in desert and subtropical regions. In Rabigh, the few persisting populations of this plant are exposed to overcutting, overgrazing and, recently, human habitation. The conservation of S. persica requires an assessment of their genetic diversity and genetic differentiation. We applied 40 simple sequence repeat (SSR) primers, with which 22 polymorphic loci were identified. The PIC values were varied between 0.858 and 0.967. 240 plant accessions were sampled from four sites in Rabigh: Wadi EL Khaneg, Wadi Al Johfa, Wadi Al Hakak, and Wadi Khurieba. The percentage of polymorphic loci PPL% were ranged between 60% and 32% and a considerable inbreeding value (F = 0.942). Elevated genetic differentiation among the populations and a low gene migration suggest isolation among S. persica populations. Several recommendations for the protection of the existing populations, including seed preservation, restoration of highly endangered sites, and management of cutting and grazing activities.

COTONEASTER orbicularis Schltdl, native to Egypt and the eastern part of the Arab peninsula, is an endangered species and the surviving individuals are dispersed in the mountains of South Sinai, Egypt. Several threats, including habitat aridification and the impact of human interference have caused a noticeable reduction in population size and number. Analyzing the genetic diversity and mating system of C. orbicularis is crucial for its conservation and management. In this study, six polymorphic microsatellite markers, formerly developed as species-specific markers, were used to assess the genetic variability and extent of inbreeding in the C. orbicularis populations. Flow cytometry of seeds was used to establish genome size. Low total heterozygosity (HT = 0.464) for all loci and populations, high differentiation between populations (FST = 0.634, RST = 0.889), and high levels of inbreeding (F = 0.906) were found. Most of the embryos possessed about 1.9 pg/2C DNA; however, embryos with 3.8 pg/2C DNA also occurred. The results provide markers that can be used in the management of conservation, including habitat recovery and ex-situ conservation, in order to prevent extinction.