EFFECT OF THIDIAZURON, NAA AND BAP ON IN VITRO PROPAGATION OF ALSTROEMERIA AURANTIACA CV. ‘ROSITA’ FROM SHOOT TIP EXPLANTS

Abstract

The objective of the study was to evaluate the potency of Thidiazuron (TDZ) as a
\nplant growth regulator when compared to combined auxin (NAA) and cytokinin
\n(BAP) in evoking morphogenic responses from Alstroemeria aurantiaca cv. ‘Rosita’
\nshoot tip explants. Shoot tips cultured on basal medium devoid of any plant growth
\nregulators (PGRs) only increased slightly in length and formed only one leaf per
\nshoot during the culture period. The addition of various PGRs to the induction or
\nculture medium significantly influenced the number and length of shoots as well
\nas the number of leaves formed. While low concentrations of TDZ (0.1 ¼M) had
\nno significant effect and high concentrations (5.0 ¼M) were inhibitory, medium
\nconcentrations (0.4-1.0 ¼M) significantly increased the number and length of shoots
\nas well as the number of leaves formed from the explants. The longest shoots were
\nformed from explants cultured in media supplemented with 1.0 ¼M TDZ. Slightly
\nbetter but comparable responses were observed from explants cultured on media
\nsupplemented with 1.0 mg/L BAP and low concentrations (0.01 mg/L) of NAA. The
\nexplants cultured in 1.0 mg/L BAP + 0.01 mg/L NAA formed the greatest number of
\nshoots while those cultured in 1.0 ¼M TDZ formed the greatest number of leaves/
\nex-plant. Increasing the NAA concentration to 0.1 mg/L and combining this with
\neither 1.0 mg/L BAP or 1.0 ¼M TDZ depressed shoot formation and shoot length.
\nIn conclusion, TDZ at concentrations between 0.4 and 1.0 ¼M were just as effective
\nas combined auxins (NAA) and cytokinin (BAP) in evoking morphogenic responses
\nfrom Alstroemeria aurantiaca cv. ‘Rosita’ shoot tip explants.