Effect of coconut water from different fruit maturity stages, as natural substitute for synthetic PGR In in vitro potato micropropagation

Abstract

The present in vitro study was conducted to investigate the hormonal efficiency of coconut water on the growth of plantlets of potato variety Desiree. The coconut water was collected from different fruit maturity stages i.e. one, two and six months old coconut fruit and used in three different concentrations i.e. 75ml/L, 150ml/L and 300ml/L each in MS medium instead of synthetic plant growth regulators (PGRs). The results showed that six months old coconut water (T3) significantly increased the number of roots (8.3), root length (4.92cm), shoot length (6.10cm), stem diameter (2.69mm), no of nodes (6.73) and leaf area (0.527cm 2 ) of the potato plantlets at transferable plant stage. However, one month old coconut water (T1) seems to be effective at C3 concentration (300ml/L) while, the two months old coconut water suppressed the growth of the potato plantlets at lower concentrations i.e. 75ml/L and 150ml/L with callus formation and no roots but at C3 (300ml/L) the shoot length increased up to 3.93cm with multiple shoots. It has been concluded that the concentration of plant growth hormones (auxin, cytokinin, gibberellins) present in coconut water changes with fruit maturation which has affected the in-vitro growth of potato plantlets significantly, therefore, it can be used instead of synthetic plant growth regulators (PGRs) in MS media for potato micropropagation.