In this study, the positive role of hydrogen peroxide (H₂O₂) pretreatment in mitigating the adverse impacts of seawater stress has been evaluated in two wheat (Triticum aestivum L.) cultivars, namely Gemmiza 11 as a salt-sensitive and Misr 1 as a salt-tolerant cultivar, with contrasting phenotypes in response to the salinity stress. Under normal conditions, wheat seeds eustress with H₂O₂ have shown significant effects on the improvement of plant growth parameters, such as dry weight and root and shoot lengths. Under salt stress conditions, seeds eustress with H₂O₂ have shown a reduction in damage to plant growth and physiological parameters as compared to the seeds kept as un-primed in both wheat cultivars. In addition, eustress of seeds with H₂O₂ has induced an increment in the pigments content, proline level and mineral uptake (K⁺, Ca²⁺ and Mg²⁺). Moreover, seeds eustress with H₂O₂ have shown significant decrement in Na⁺ content uptake in plants and that subsequently reduced lipid peroxidation. Seawater stress has increased the activity of the antioxidant system based on catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in both cultivars, except POD in Gemmiza 11. Similarly, the application of H₂O₂ has further enhanced the activity of the antioxidant system in stressed plants and this enhancement of the antioxidant system further reduced Na⁺ content in plants and subsequently increased the growth parameters. Results of inter-simple sequence repeat (ISSR) markers have shown clear differentiation among the treatments and have provided strong evidence in support of the hypothesis proposed in this study that H₂O₂ eustress improves seed tolerance and enhances plant growth parameters under seawater stress.

Aerva javanica is one of Egypt’s most important traditional medicinal plants used as antidiarrheal and anthelmintic medicine and recently as an anticancer agent. In this study, variations among ten populations of Aerva javanica in different sites in the Eastern Desert of Egypt were analyzed based on morphological and ecological attributes and molecular variation expressed by Inter-Simple Sequence Repeat (ISSR) markers. Morphological diversity was higher for populations in the Wadi El-Markh and Bir Abbady regions than others. The polymorphism revealed by ten ISSR primers was 79.4% among populations. Distance trees created using the results obtained from soil variables, morphological characterizations, and molecular data showed that the highest similarity was 0.974 between Populations 8 and 9, while the lowest similarity was 0.715 between Population 1 and Population 3 regions. In conclusion, the obtained data are important to design a plan for sustainable conservation of Aerva javanica as an important medicinal plant having a wide interspecific genetic variability within various populations.

Cytological and physiological effects resulted from aqueous extracts of Aster squamatus, Euphorbia terracina, Euphorbia peplus, Syzygium aromaticum, Acacia pycnantha, Aloe vera, Euryops arabicus and Tamarix aphylla to the growth of Chinese faba bean (Vicia faba L.) seedlings were evaluated. Examined growth parameters including seeds germination percentage and the fresh and dry weights of root and shoot and their length greatly affected by types of extracts during the time course of germination. Among all tested extracts the Syzygium aromaticum (Clove) and Euphorbia peplus extracts found to be mitodepressant and induced noticeable frequencies of traditional chromosome aberration. Those two extracts also caused significant decreases to the length, fresh and dry weights of root and shoot of Chinese faba bean seedling. Euphorbia terracina and Tamarix aphylla extracts caused complete success of seed germination while Aster squamatus, caused noticed stimulation in root length, root fresh weigh (mg/plant) and root dry followed by Euphorbia terracina. Euryops arabicus caused significant stimulation in shoot length, shoot fresh weight, root lenght and in root fresh and dry weight followed by Tamarix aphylla.