Effect of different plant growth regulators on rooting performance of cuttings of mungbean

Exogenous application of different types of auxins (IBA, IAA, NAA, 2, 4-D and NOA) caused quite different and variable effects on root primordia development, first order root establishment, second order root and total root length per cutting of mungbean (Vigna rediata L. cv. 105). Among them, IBA was most effective for improving the development of root primordia and second order root, wheareas IAA was most efficient for establishing root primordia and for increasing the total root length per cutting. Exogenous application of polyamines (putrescine, spermindine and spermine) had no effect on root primordia development and only putrescine had an effect on increasing the number of second order roots and total root length per cutting. Exogenous application of auxins and polyamines in water stress-pretreated cutting mitigated the inhibitory effect of water stress on adventitious root formation. Among auxins, only IBA was effective while others have no favourable effect under stress. Polyamines have only limited effect in water stressed, cuttings.