On the other hand, Shinde et al (2010) observed the highest biomass of Psoralea corylifolia hairy roots when MS medium was supplemented with NH4+ and NO3- at a ratio of 20:10. Decreasing the NH4+ concentration to 10 and 0 mM in the medium significantly reduced the hairy root growth. Similarly, decreasing the NO3- concentration had the same effect on the hairy root growth.
Therefore, a balanced ratio of NH4+ to NO3- is an important factor for enhancing the growth of hairy root cultures in the V. officinalis.