Development of Liquid Culture System for Rapid Multiplication of Gyrinops walla

Agarwood is an expensive resinous compound, produced by Gyrinops walla as defence response to external damages. The tissue culture technique is the best alternative for both rapid multiplication and product synthesis. This study demonstrated an efficient method of rapid multiplication using liquid cultures for G. walla. MS medium supplemented with 1.0 mg/L BAP and 0.1 mg/L IBA, 100 mg/L Myoinositol and 30.0 g/L of sucrose, and 3.0 g/L Phytagel (Sigma-Aldrich) was used as the control (T0). The effect of shoot growth on liquid culture on the same medium was investigated without inert support (T1) and kept on a shaker, with the support of filter paper bridges (T2), rigid support (T3), wet foam (T4), and a double layer of liquid and semi-solid medium (T5). At the end of the sixth week, growth rates and cell doubling times were calculated. Results showed significant differences between treatments at α=0.05 probability level (P< 0.0001). All liquid cultures except T3 stimulate the biomass. T1 had the highest growth rate (0.38 g/week) and the shortest cell doubling time (1.82 weeks) of G. walla (11-13 shoots from one shoot), but it also had hyperhydricity, which was overcome by combining liquid cultures with a flexible matrix or using a double-layer system. The nature of the matrix was found to be a vital factor in achieving the desired benefits of the liquid cultures. The use of a matrix is unnecessary if T5 is used to achieve the desired results.