Possible Rejuvenation of Adult Avocado by Graftage onto Juvenile Rootstocks in Vitro

Avocado ( Persea americana Mill.) seedlings germinated aseptically were used as rootstocks. Lateral buds excised from greenhouse-grown flowering-age plants and disinfested, were used as scions. About 50% of the shoots that emerged from the scions showed restored rooting competence. The shoots continued to root when the terminals of rooted shoots were severed and retested. Nodal sections from grafted adults also produced rootable shoots. It is suggested that the restored rooting competence reflected a developmental phase reversal from adult to juvenile rather than a simple transfer of rooting cofactors from rootstock to scion.