Arbuscular mycorrhizae and rhizobacteria improve growth, nutritional status and essential oil production in Ocimum basilicum and Satureja hortensis

The effects of arbuscular mycorrhiza fungi (AMF) species (Glomus intraradices and G. mosseae), nitrogen (N) fertilizer and plant growth-promoting rhizobacteria (PGPR) on growth characteristics, essential oil (EO) content, nutrient uptake and components of medicinal plants basil (Ocimum basilicum) and satureja (Satureja hortensis) were studied. The use of these fertilizers significantly (P < 0.05) increased plant height, root length, fresh and dry weights of shoots and roots, number of shoot branches and number of inflorescences per plant, EO content, phosphorus (P), nitrogen (N), iron (Fe), potassium (K), and copper (Cu) content. Moreover, application of AMF and PGPR significantly (P < 0.05) enhanced linalol, methyl chavicol, trans-geraniol, camphor and limonene concentrations in basil EO and carvacrol, thymol, p-cymene, alpha-terpinene and gamma-terpinene in satureja EO components. G. mosseae application achieved the highest increases in basil and satureja EO percentage by 39 % and 25 %, respectively, compared to plants treated with mineral fertilizer, and 80 % and 50 %, respectively, compared to unfertilized plants. The highest N, K, Fe and P concentrations in basil and satureja were obtained when PGPR or G. mosseae were used. This study shows that application of biofertilizers not only improves yields in medicinal plants, but they also play a significant role in increasing their bioactive compounds and plant nutrition.