Interactive Effects of Arbuscular Mycorrhizal Inoculation with Nano Boron, Zinc, and Molybdenum Fertilization on Stevioside Contents of Stevia (Stevia rebaudiana, L.) Plants

Abstract

Stevia (Stevia rebaudiana, L.) is receiving increasing global interest as a diabetes-focused herb associated with zero-calorie stevioside sweetener glycoside production. This study was conducted to determine whether the arbuscular mycorrhiza (AM), as a biofertilizer integrated with nano boron (B), zinc (Zn), and molybdenum (Mo), would improve stevia growth and stevioside content. A factorial experiment with four replicates was conducted to evaluate the effect of AM at 0, 150, and 300 spore/g soil and three nano microelements B at 100 mg/L, Zn at 100 mg/L, and Mo at 40 mg/L on growth performance, stevioside, mineral contents, and biochemical contents of stevia. Results indicated that the combination of AM at 150 and B at 100 mg/L significantly increased plant height, number of leaves, fresh and dry-stem, and herbal g/plant during the 2019 and 2020 growing seasons. Chlorophyll content was increased by the combination between AM at 150 spore/g soil and B at 100 mg/L during both seasons. Stevioside content in leaves was increased by AM at 150 spore/g soil and B at 100 mg/L during the second season. In addition, N, P, K, Zn, and B in the leaf were increased by applying the combination of AM and nano microelements. Leaf bio constituent contents were increased with AM at 150 spore/g soil and B at 100 mg/L during both seasons. The application of AM and nano B can be exploited for high growth, mineral, and stevioside contents as a low-calorie sweetener product in stevia.

Response of Seeds, Oil Yield and Fatty Acids Percentage of Jojoba Shrub Strain EAI to Mycorrhizal Fungi and Moringa Leaves Extract

“…This improvement is due to the role of arbuscular mycorrhizal fungi in increasing absorption of water and nutrients, and enhances transport of immobile mineral elements through exploring larger volumes of the soil by mycorrhizal hyphae to stimulate the growth of plants [46]. These results are in harmony with studies by Davies et al [17] on pepper, Ruiz-Lozano and Azcon [18] on lettuce, Auge et al [19] on the common bean, Ruiz-Lozano et al [20] on soybean, Ortas [21] on maize, wheat and cotton, Roldan et al [23] on juniperus, Ortas and Rattan [24] on pepper, wheat and maize, Tobar et al [25] on lettuce, Igiehon et al [26] on soybean, Jabborova et al [27] on spinach, Jabborova et al [28] on ginger, Zewail et al [29] on stevia and Ortas [47] on twelve plant species.…”

“…In addition, mycorrhizal fungi increase the resistance to drought and salinity stresses as well as pests and soil-borne diseases and improve growth and osmotic adjustment through stimulating the production of growth-regulating substances [16]. In this field, many studies such as those by Davies et al [17] on pepper, Ruiz-Lozano and Azcon [18] on lettuce, Auge et al [19] on the common bean, Ruiz-Lozano et al [20] on soybean, Ortas [21] on maize, wheat and cotton, Karandashov and Bucher [22], Roldan et al [23] on Juniperus, Ortas and Rattan [24] on pepper, wheat and maize, Tobar et al [25] on lettuce, Igiehon et al [26] on soybean, Jabborova et al [27] on spinach, Jabborova et al [28] on ginger and Zewail et al [29] on stevia were conducted.…”