Chitosan elicitor stimulation of in vitro growth and ex vitro acclimatization of Lantana camara L.

Abstract

The efficiency of chitosan on in vitro growth and ex vitro acclimatization of lantana (Lantana camara L.) was compared to thidiazuron (TDZ) or indole-3-butyric acid (IBA). It was found that chitosan promoted in vitro shoot regeneration. Lantana shoots cultured on Murashige and Skoog (MS) medium supplemented with 2.8 mg/L TDZ and 0.1 mg/L high molecular weight chitosan (HMC) produced the highest shoot number of 14.2 ± 6.1 shoots with long lengths of the main shoot and axillary shoot of 3.95 ± 0.96 cm and 0.29 ± 0.12 cm, respectively. Plantlets cultured on MS medium supplemented with 0.1–0.5 mg/L low molecular weight chitosan (LMC) or HMC had root induction of 73.7–94.7% and axillary shoot proliferation of 50.0–61.6%. After transplanting, the plantlets were treated with foliar and soil applications of 0.6 mg/L HMC of 5 mL three times weekly. The chitosan treatment increased the survival percentage and growth of plantlets ex vitro. Plantlets obtained from the MS medium supplemented with 1.5 mg/L IBA and 0.3 mg/L HMC or with only 0.3 mg/L HMC had high survival rates of 82.0% and 81.0%, respectively. The highest fresh and dry weights were for the plantlets derived from the MS medium supplemented with 1.5 mg/L IBA and 0.3 mg/L HMC. Chitosan treatment after transplanting could increase the survival percentage. In addition, the highest biomass resulted from applying both in vitro and ex vitro treatments. This suggested chitosan could be a stimulator for lantana shoot growth in vitro and for acclimatization ex vitro.