Trichoderma viride

Mastan, Anthati, Rane, Digeshwar, Dastager, Syed G. & Babu, C. S. Vivek, 2021, Molecular insights of fungal endophyte co-inoculation with Trichoderma viride for the augmentation of forskolin biosynthesis in Coleus forskohlii, Phytochemistry (112654) 184, pp. 1-10 : 8

5.3. Co-inoculation of endophytic fungi with Trichoderma viride

Prior to co-inoculation studies, compatibility between each fungal endophyte and T. viride was tested using dual culture method and found no antagonism between endophytes and T. viride . Further, co-inoculation studies were carried out under field conditions at CSIR–CIMAP Research Centre, Bangalore in an experimental plot (3 × 3 m) of red-sandy loom soil (pH 6.2). Thirty-days-old nursery plants of C. forskohlii were transplanted into 10–12 cm deep holes with spacing of 60 × 60 cm between plants. Four rows were maintained in each treatment plot (total of 8 plots) and divided by a guard ridge (50 cm width) to avoid direct contact with adjacent plots. Each experimental plot was planted with 16 plants in four rows (hence, 4 plants were in the middle surrounded by 12 peripheral plants). The four central plants (four replicates) from each treatment were selected for the measurement of growth parameters. The fungal cultures were grown in 500 mL potato dextrose broth for 7 days at 28 ◦ C and the resulting mycelia were diluted with 90 mL of phosphate buffered saline (PBS) (K2HPO4 0.24 g L 1, Na2HPO4 1.44 g L 1, KCl 0.2 g L 1, NaCl 8 g L 1 and pH 7.40). Finally, fungal suspension was diluted to a density of 1 × 108 CFU mL 1. After 30 days of transplantation, each plant in the experimental plot was treated with 30 mL inoculum of SF1, SF2, RF 1 or TV1 and the untreated experimental plot (n = 16 plants) was considered as control. Co-inoculation treatments included RF 1+TV1, SF1+TV1, and SF2+TV1 at an inoculum of 1:1 ratio ( Egamberdieva et al., 2017). For each treatment plot, plant growth measurements comprising number of branches and plant height were analyzed for every 30 days until harvest. After 150-days of transplantation, plants were harvested by manually uprooting each plant with utmost care so as to not damage the roots. Fresh weights of roots and shoots were measured at the time of harvest and dry weights of roots and shoots were measured after 4-weeks of drying period; root length and number of tuberous roots per plant were also recorded. The obtained values of endophyte treatments (alone and co-inoculum) were compared with endophyte uninoculated control plants.