Effect of NAA and IBA on in vitro regeneration and hardening in cassava(Manihot esculenta Crantz.)

Abstract

As the cassava is a delicate plant to harden during in vitro regeneration, huge losses occur duringtransfer from in vitro laboratory to in-situ field conditions. One month old in vitro plantlets of cassavavarieties “Sree Vijayaâ€, “H-226†and “H-165†released by Central Tuber Crops Research Institute, India grown from in vitro nodal explants using MS media supplemented with NAA or IBA along with a control were used for hardening studies. For in vitro rooting with shoot regeneration, MS media supplemented with 0.3 mgl-1 IBA was found to be the best for all the three varieties. Cassava plantlets grown using 0.6% agar in the in vitro growth medium with NAA supplement produced least root damage (3%) during washing before hardening. All the varieties grown in MS media supplemented with NAA, showed good results during hardening. Cassava varieties Sree Vijaya and H-226 grown in vermiculite + soil as potting mixture using both Hoagland and fertilizer solution showed maximum success of 87% and 80% respectively. Cassava var. H-165 showed best result from the potting media sand + vermiculite + soil using both Hoagland and fertilizer solution, which gave 100% success. The hardened plantlets could be successfully acclimatized in the green house and transplanted to open field conditions.