The Effect of Bolete (Phlebopus portentosus) Innoculation on The Growth of Siamese Rosewood (Dalbergia cochinchinensis) Seedlings

The effect of bolete (Phlebopus portentosus) inoculation, which is a highly favored edible mycorrhizal mushroom, on the growth of Siamese rosewood (Dalbergia cochinchinensis) seedlings, which is a highly valued tree, was investigated. Completely Randomized Design (CRD) with seven treatments was used. The treatments were: control group (no inoculation); inoculation with 10, 20, and 30 ml of P. portentosus inoculum, inoculated once and twice with a 15-day interval between inoculations. Four-month-old D. cochinchinensis seedlings were used in the experiment. Growth parameters were recorded for 180 days after inoculation. It was found that two inoculation of 20 ml gave the best results. The result showed that the average quantities of chlorophyll A, chlorophyll B, and total chlorophyll content that were measured were 3.23±0.03, 1.40±0.12, and 4.63±0.09 mg.g-1, respectively. The average quantities of chlorophyll A and total chlorophyll were significantly different from the control group at the statistical level of P<0.05. The average stem height, diameter at root collar, canopy width, and total biomass were 62.94±13.07 cm, 8.22±1.13 mm, 41.69±5.78 cm, and 23.47±8.13 g, respectively. The results were significantly different from the control group at the statistical level of P<0.05. The correlation analysis between amount of chlorophyll A and plant growth indicators showed that the correlation coefficient between chlorophyll A and stem height was highest (R² = 0.7512), followed by total biomass, diameter at root collar, and canopy width respectively. P. portentosus attached to D. cochinchinensis seedlings roots were examined by Scanning Electron Microscope (SEM) at 100 μm. The results showed that the inoculated roots had mycelium attached to the surrounding root surface. The study results could be used as a guideline to promote re-forestation by using mycorrhizal mushroom (P. portentosus) along with economic trees for increasing plant growth.