Arbuscular mycorrhiza influences the growth and biochemical parameters of Cassia fistula L. seedlings, contrasting with the naturally occurring established trees

Abstract: The efficacy of rhizospheric native arbuscular mycorrhizal fungi from naturally growing Cassia fistula L. trees was evaluated by utilizing seeds from the same trees to assess growth and biochemical properties. This study aimed to investigate whether biochemical content could be augmented in naturally growing trees, contrasting them with greenhouse-grown seedlings. The findings revealed that arbuscular mycorrhiza-inoculated seedlings exhibited significantly higher shoot and root length, leaf area, and shoot dry weight compared to non-mycorrhizal plants under greenhouse conditions. Furthermore, there was a noteworthy increase in biochemicals such as protein, carbohydrates, and phenols in mycorrhizal-inoculated plants and naturally growing trees when compared to non-mycorrhizal plants. Interestingly, carbohydrates and phenols were significantly more abundant in naturally growing trees than in greenhouse experiment plants. Additionally, the methanolic leaf extract of non-mycorrhizal plants exhibited the lowest inhibition percentage (%) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals in comparison to mycorrhizal plants and naturally growing trees. Moreover, the effective concentration at 50% inhibition of DPPH radicals by mycorrhizal plants and naturally growing trees was lower than that observed in non-mycorrhizal plants. The biochemical estimates obtained from mycorrhizal plants substantiate the results observed in naturally growing trees, thereby supporting the assumption that native arbuscular mycorrhizal fungi may enhance the levels of biochemicals in naturally growing C. fistula trees.