Effect of biofertilizers and rhizospheric bacteria on growth and root ultrastucture of lettuce

Abstract

Biofertilization is a technique that uses plant and animal wastes to add organic matter and nutrients to the soil. It can also use microorganisms that can metabolize these by-products to facilitate their absorption by the plant roots. In this study, we tested the effects of rhizospheric bacteria inoculation (T1), a combination of rhizospheric bacteria with liquid fertilizer (T2) and uncombined liquid fertilizer (T3), on the growth, nutritional content, root tissue, and root cells of lettuce plants. The results showed significant positive differences in all treatments compared to control plants, in terms of morphological, nutritional, and productivity parameters. The combination of rhizospheric bacteria with liquid SEFEL fertilizer (T2) yielded the best results, showing increased fresh and dry weight, and diameter. There were no differences between treatments for nutritional content, but each treatment outperformed the control by more than 700% for all macronutrients. The best result was phosphorus content for T1, with 1272.22% more than control. Regarding root structure and ultrastructure, there was no variation in tissue organization compared to control plants, but increases in root hairs (T1), development of transfer cells (T2), and secondary growth (T3) were observed. Additionally, colonization of roots by rhizospheric bacteria was confirmed in all three treatments. In conclusion, this study suggests that inoculating with rhizospheric bacteria is a viable and environmentally friendly biofertilization for lettuce plants.