IN VITRO PROPAGATION OF VANILLA PLANIFOLIA ANDREWS BY PROLIFERATION OF AXILLARY BUDS

Abstract

Vanilla planifolia (V. planifolia), a high-value crop due to the vanillin extract in its fruits, is a tropical orchid that can adapt and be profitably cultivated in Vietnam. This study describes a regeneration protocol of V. planifolia using nodal explant. Three different strengths of Murashighe and Skoog (MS) medium containing 100 ml/L coconut water (CW) were screened for their effects on shoot regeneration and development. Results indicated that the half-strength MS medium was a promising basal medium for vanilla tissue culture. Among all evaluated concentrations (0.0, 0.1, 0.3, 0.5, and 1.0 mg/L) of 6-benzylaminopurine (BA), the addition of 1 mg/L BA to that medium significantly produced the highest multiplication rate (p < 0.001) with 3.67 ± 0.08 shoots per explant. Regenerated shoots were transferred to half-strength MS medium supplemented with 0.1 mg/L BA and three types of organic additives for growth and development. Banana homogenate (100 g/L) significantly promoted shoot extension (6.22 ± 0.25 cm), leaf development (5.03 ± 0.03 leaves per shoot with a mean length of 3.10 ± 0.13 cm), root formation (3.83 ± 0.07 roots per shoot) and root elongation (5.42 ± 0.21 cm) compared to CW (100 ml/L) and peptone (1 g/L). The combination of NAA (0.1, 0.3, 0.5 mg/L) to medium containing CW (100 ml/L) and BA (0.1 mg/L) did not significantly improve root production (p = 0.178) and elongation (p = 0.231) after 3 weeks of culture. The findings in this study would help establish an efficient and viable protocol for industrial micropropagation to provide adequate planting materials for V. planifolia in Vietnam