Efficacy of indole-3-acetic acid-producing PGPFs and their consortium on physiological and biochemical parameters of Trigonella foenum-graecum L

Fungi produce phytohormones like indole-3-acetic acid (IAA), which stimulates the growth of plants. In the present study, Aspergillus niger (AN) and Aspergillus caespitosus (DS-3) were identified in screens for highly efficient IAA-producing fungi. Initially, IAA production was assessed through UV-Visible spectroscopic analysis using Salkowski's reagent. HPTLC confirmed the presence of IAA in all fungal extracts when compared with the standard IAA. HPTLC analysis revealed that AN exhibit the highest IAA production, which was 251.86 +/- 0.7 mu g ml(-1). AN, DS-3 and a combination of both strains as a growth-promoting consortium (GPC-1) were applied to Trigonella foenum-graecum L seeds for 6 h. After 14 days, the fenugreek plants were used for both the physiological and biochemical analysis. Results indicated that the GPC-1 induced more desirable physiological properties, with higher protein content, carbohydrate content, total phenolic content and antioxidant activity compared to treatment with individual PGPFs or distilled water. The extract from fenugreek plants treated with GPC(-1) had the maximum diosgenin content (342.374 +/- 0.67 mu g ml(-1)), as assessed by HPTLC. [GRAPHICS] .