Role of plant growth substances in regulating pseudomonocotyly and correlative inhibition in some alpine Himalayan rosettes

Some alpine Himalayan rosette plants (e.g., Aconitum heterophyllum Wall and Podophyllum hexandrum Royle) exhibit the phenomenon of “pseudomonocotyly”, where the plumule remains in a quiescent stage at the base of cotyledonary tube, due to the inhibitory influence of the cotyledons. This correlative inhibition prevents the formation of true leaves and is considered to be an adaptation strategy for seedlings to cope with the prevailing harsh climatic conditions. However, the role of plant growth substances (PGSs) on these processes is not fully understood. This study examines the relative role of PGSs like indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellic acid (GA3) and cytokinin (CK) in the regulation of these processes. The external application of PGSs like GA3 and CK reduced the correlative inhibition, and thus, induced early leaf emergence. Promoting early leaf emergence in such plants has direct implications in nursery raising and conservation of these high value Himalayan medicinal plants.