Improvement of growth and root specific flavour compound 2-hydroxy-4-methoxy benzaldehyde of micropropagated plants of Decalepis hamiltonii Wight & Arn., under triacontanol treatment

Decalepis hamiltonii (swallow root) belongs to Asclepiadaceae and is an endangered shrub. It is generally considered as a tuberous root food mostly in the southern part of India, being a good source of bioactive compounds and flavour compounds with 2-hydroxy-4-methoxy benzaldehyde as the major constituent which resembles vanillin. We improved D. hamiltonii plant growth and yield of tubers with enhanced flavour compound, by using triacontanol (TRIA) soil drenching. Irrespective of the plant source, the interactive difference of the TRIA concentration and TRIA treatment interval showed the marked difference for yield and flavour content. The administration of triacontanol (0.228 μM) soil drenching twice by giving second treatment with a gap of 60 days after initial treatment, showed fast sign of growth and good yield of tubers with enhanced flavour content. The GC-MS profiles of flavour compound 2-hydroxy-4-methoxy benzaldehyde in tubers showed significant improvement over controls (1.5 times more), which could be useful for various commercial applications.