Effects of thiamine spraying on biochemical and morphological traits of basil plants under greenhouse conditions

The effects of thiamin (Thi) applied as foliar spray on some morphological and physiological traits were investigated in basil (Ocimum basilicum L.). Four levels of Thi including 0 (distilled water), 250, 500 and 750 µM were tested in a randomized complete design with three replications at research greenhouse of University of Guilan, Iran. Thi exerted a significant effect on the most studied indices. The highest amounts of leaf, stem and root dry weights and number of lateral branches were obtained in plant which were treated by 500 µM Thi. Thousand grain weight increased by increase in Thi levels, as, its value in 700 µM Thi, was 26% more than control. Thi spraying especially in concentration of 750 µM improved the leaf nutrients content (N, P and Ca). Chlorophyll b content in leaves affected positively by Thi, and its highest value obtained in 750 µM treatment (0.75 mg g-1 FW). The highest and the lowest phenolic compounds were gained in 0 and 750 µM levels of Thi (47.2 vs. 40.3 mg 100g-1 FW). Similar trend was observed about total antioxidants, where their content in 750 µM was 13% more than control treatment. Generally, it seems that Thi can be considered as an appropriate growth regulator in basil medicinal plant cultivation.