Interactive effects of boron stress and mycorrhizal (AMF) treatments on tomato growth, yield, leaf chlorophyll and boron accumulation, and fruit characteristics

Abstract

High levels of boron (B) in soils cause toxicity in tomatoes, but inoculation of arbuscular mycorrhizal fungi (AMF) into plants can reduce it. This study aimed to evaluate the effects of AMF inoculation on morphological parameters (shoot height, plant fresh and dry weights), yield, leaf chlorophyll and boron content, and fruit characteristics (weight, water and soluble solid contents, firmness, color) of tomato plants grown in boron stress (0.06, 0.5, 1.0, 2.0, 4.0, and 8.0 mM). Increased boron concentrations reduced all parameters except leaf boron content, fruit soluble solids and firmness. However, the highest values of the morphological parameters, fruit soluble solid contents and red color values (control, 0.5 and 1.0 mM B), fruit yield (<8.0 mM B), leaf chlorophyll content (<= 2.0 mM B), fruit weight (control, 0.5 and 2.0 mM B), fruit firmness (control and 1.0 mM B) were obtained from mycorrhizal plants. No significant differences were found between the fruit water content and color values (brightness and yellow) of non-mycorrhizal and mycorrhizal plants in all boron stress levels. The leaf boron concentration in inoculated with mycorrhizal fungi had lower than non-inoculated ones. These results suggest that mycorrhizal-inoculation may limit excessive boron uptake and alternatively be used in boron contaminated soils.