Melatonin (MT) is a pleiotropic molecule with diverse and numerous actions both in plants and animals. In plants, MT acts as an excellent promotor of tolerance against abiotic stress situations such as drought, cold, heat, salinity, and chemical pollutants. In all these situations, MT has a stimulating effect on plants, fomenting many changes in biochemical processes and stress-related gene expression. Melatonin plays vital roles as an antioxidant and can work as a free radical scavenger to protect plants from oxidative stress by stabilization cell redox status; however, MT can alleviate the toxic oxygen and nitrogen species. Beyond this, MT stimulates the antioxidant enzymes and augments antioxidants, as well as activates the ascorbate–glutathione (AsA–GSH) cycle to scavenge excess reactive oxygen species (ROS). In this review, we examine the recent data on the capacity of MT to alleviate the effects of common abiotic soil stressors, such as salinity, alkalinity, acidity, and the presence of heavy metals, reinforcing the general metabolism of plants and counteracting harmful agents. An exhaustive analysis of the latest advances in this regard is presented, and possible future applications of MT are discussed.

Thirteen exetic and advanced peanut breeding genotypes, and two check cultivar (Giza/6 and Ismailia 2) were evaluated for yield and yield component under eighteen divers environments condition i.e. three years (2017, 2018 and 2019), three locations (Ismailia, Shandawell and Toshka) Reasearch station and two sowing dates (1 st April and 1 st June). The components of G x E interaction, phenotypic and genotypic stability parameters were estimated according Eberhart andRussel (1966) and Tai method (1971). The obtained results revealed that Pooled analysis of variance indicated, highly significant differences among genotypes, years, locations and sowing dates as well as all interactions between them for all characters, providing evidence for the necessity of testing studied genotypes in multiple environments. Phenotypic stability parameters indicated that genotypes (4 and 6) were classified as highly adapted to favorable environments for pod yield ard/fed. and oil percentage as well as line (Ismailia/2) for pod yield ard/fed. The most desired and stable lines showed genotypes (2,5 and 10) for pod yield ard/fed. under wide range variable environmental conditions; genotypes (2and 5) for shelling percentage and pod yield ard/fed. as well as genotypes (5 and 8) for 100-seed weight and oil percentage. Genotypic stability estimates showed that, the most average stable genotypes were, genotypes (2 and 10) for pod yield ard/fed., genotype (7) for 100-seed weight, genotypes (11 and 13) for shelling percentage as well as genotypes (9 and 12) for oil percentage. It is worthy to mention that, the phenotypic and genotypic of stability are quite similar for describing stability in peanut genotypes (2 and 10) for pod yield ard/fed. and genotype (13) for shelling percentage. It is therefore suggested that these genotypes may be recommended to be included in any breeding program for improving peanut pod yield stability under different environments.

Many other countries have large areas of sandy soil it can be cultivated with some soil properties improvements and reduce water loss during irrigation thus, increase water use efficiency. The present study aims to evaluate the effect of adding compost (Com) 10 ton ha -1 , bentonite (Ben) 10 ton ha -1 , and a mixture of (compost 5ton ha -1 and bentonite 5 ton ha -1 (Com/Ben) on the performance of four rice varieties Giza 178, Sakha 107, Hanyou 73 and Hanyou 737 and some physical and chemical properties of a sandy loam soil under drip irrigation system. The results showed that used Com and Com/Ben resulted a significant reduction in soil pH and soil EC as well as soil contents of Na, K, and Mg, compared with control in the soil layer (0-20cm). The treatments significantly increased organic matter, water holding capacity, field capacity, wilting point, available water, and water-holding pores, while all treatments significantly decreased hydraulic conductivity and quick drainage pores in soil layer (0-20cm) compared with the control. Rice plants have been died before the flowering stage under Com and Ben soil amendments in addition to control. Grain yield, harvest index and water use efficiency have been calculated for the rice varieties under com/Ben mixture only. Rice plants under Com/Ben showed the highest root length, plant height, tillers number hill -1 and biomass yield in comparison to Com, Ben, and control. Hanyou 737 gave the highest biomass yield, grain yield, harvest index and the highest water use efficiency under Com/Ben followed by Hanyou 73.