ENHANCEMENT OF PLANT GROWTH, CHEMICAL COMPOSITION AND SECONDARY METABOLITES OF ESSENTIAL OIL OF SALT-STRESSED CORIANDER (CORIANDRUM SATIVUM L.) PLANTS USING SELENIUM, NANO-SELENIUM, AND GLYCINE BETAINE

Two pot experiments were carried out under greenhouse conditions during the two successive winter seasons of 2017/2018 and 2018/2019 to enhance the performance of coriander (Coriandrum sativum L.) plants under salt stress conditions (NaCl at 0, 25, 50 and 75 mM). Along with the possibility of enhancing the plant growth, chemical composition, and secondary metabolites of essential oils. Foliar applications of selenium (25 and 50 ppm), nano selenium (25 and 50 ppm), glycine betaine (5 and 10 mM), and distilled water (control treatment) were applied on C. sativum plants. The foliage and root growth, chemical composition, and secondary metabolites of essential oils of coriander plants grown under salt stress were examined. The obtained results of the two seasons revealed that salt stress had significant deleterious effects on vegetative growth, fruit yield, essential oil yield, secondary components, and leaves chemical composition, while it enhanced the electrolyte leakage, proline content, Na+ and Cl- of the leaves. Generally, the tested treatments: selenium, nano selenium, and glycine betaine varied in their significant effects on the studied characters. Selenium and glycine betaine treatments were more effective in improving coriander plants to salinity stress where they significantly increased almost all the studied parameters under saline compared to the control

In vitro colonization of date palm plants by Rhizophagus irregularis during the rooting stage

The use of in vitro culture of date palm plants Phoenix dactylifera, associated with arbuscular mycorrhizal (AM) fungi is a novel approach for the production of bio-fortified plants that are free of pathogens. Here, we report, for the first time, the in vitro mycorrhization of in vitro date palm plants using the AM fungus Rhizophagus irregularis MUCL 41833. Date Plants were used in an in vitro cultured system that consisted of a root compartment (RC) containing germinated seeds of Barrel Clover, Medicago truncatula, and spores of Rhizophagus irregularis as a mycorrhizal donor, and a hyphal compartment (HC) with a barrier separating the RC from the HC. In vitro cultured date palm plants, at the two-leaf stage, were placed in the HC section of the culture plate that after 6 weeks contained an active growing extraradical mycelium network of the fungus. Roots of the date palm became colonized after 10 weeks and hyphae, vesicles, spores and arbuscules, were detected. No differences were noticed in above-ground parameters between mycorrhized and non-mycorrhized plants, in which there was no fungus in the HC. However, the total root length was significantly higher and secondary and tertiary roots were significantly more numerous, in the mycorrhized plants. It is hypothesized that these differences are related to stimulating molecules released by the profuse extraradical mycelium of the fungus growing in close contact with the palm root system. Root colonization percentages were of the same order as those reported in pots cultures of the date palm plants. This work opens the door for the large-scale in vitro mycorrhization of date palm plants, potentially better adapted to acclimatization phase and possibly to the field