The Nitrogen-Fixing Bacteria—Effective Enhancers of Growth and Chemical Composition of Egyptian Henbane under Varied Mineral N Nutrition

Egyptian henbane (Hyoscyamus muticus L.) plants are rich sources of alkaloids used in pharmaceutical products. Recently, rising efforts have been devoted to reducing mineral fertilizer supply, production cost, and environmental pollution via decreasing the doses of nitrogenous fertilizers and adopting biofertilizer farming systems. Two field experiments were conducted to examine the potential role of N fixing bacteria Azotobacter spp. and Azospirillum spp. on the growth, mineral status, tropane alkaloids, leaf anatomy, and seed yield of Egyptian henbane grown with different levels of mineral nitrogen fertilizer, i.e., 25%, 50%, and 100% of the recommended dose, equal to 30, 60, and 120 kg N ha−1. N fertilizer improved growth, mineral elements, tropane alkaloids, seed yield, and yield components of Egyptian henbane, which showed a gradually rising trend as the rate of N fertilizer increased. High doses of N fertilizer presumably elicited favorable changes in the anatomical structure of Egyptian henbane leaves. The application of 50% N dose plus N fixing bacteria affected Egyptian henbane trials similarly to 100% of recommended N dose. In conclusion, the N fixing bacteria proved to be a sustainable tool for a two-fold reduction in the recommended dose of mineral N fertilizer and the sustainable management of Egyptian henbane nutrition.

Future outlook of plant growth regulators application influencing callus induction from different type explant Hyoscyamus muticus L. in vitro

The article shows the results concerning the problem of the influence of the hormonal composition of the medium on callus induction in isolated from different explants of Egyptian henbane areas (on the example of Hyoscyamus muticus L.). The authors study 11 variants of Murashige and Skoog medium supplemented with different concentrations and combination of auxins and cytokinins. It was important to find nutrient medium modification of Murashige and Skoog for callus induction. The article describes the fact that callus formation from different explant types of Hyoscyamus muticus L. in vitro was observed on Murashige and Skoog medium fortified with benzylaminopurine and naphthylacetic acid. It shows that the maximum callus induction was observed from root explants on Murashige and Skoog's medium supplemented with 0.5 mg/l of benzylaminopurine and 1.0 mg/l of naphthylacetic acid. And minimal callus formation was observed in the area with benzylaminopurine. Callus induction of leaf and stem explants both on the hormone-free nutrient medium and with the benzylaminopurine only was not observed. Thus, the results show that the frequency of callus formation with culturing root segment is higher compared to leaf and stem segment explants (on the example of Egyptian henbane in culture in vitro ). This work aims to inducing callus formation from various explants of Egyptian henbane, which can be used for plant regeneration or as a source for in vitro production of secondary metabolites.