Optimization of the in-vitro culture protocol of Haworthiopsis viscosa and Haworthia truncata var. truncata

Abstract

This study was conducted to optimize the in vitro culture of Haworthiopsis viscosa and Haworthia truncata var. truncate. The full and half concentration of Murashige and Skoog (MS) and Gamborg (B5) after the disinfection of the explants was used to determine the suitable medium culture. The effect of the different concentrations of 6-benzyl aminopurine (BA) and Kinetin (Kin) (0, 1, 2, 3 and 6 mg/L) was investigated on the percentage of regeneration, callus formation and the number of seedlings regenerated. The different concentrations of indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA) (0, 0.5, 1 and 1.5 mg/L) were used to investigate the seedlings rooting. Finally, the cocopeat + perlite, the sand +perlite and the vermicolit +perlite substrates were studied to determine the suitable substrate for compatibility. The results show that the use of MS culture medium at complete concentration was more successful than the other treatments and increased the regeneration and seedling percentage in both species. Also, the use of BA at a concentration of 1 mg/L (H. truncata var. truncate) and at a concentration of 3 mg/L (H. viscosa) increased the percentage of regeneration and the number of regenerated seedlings significantly and the regenerated seedlings had a very good quality. The rooting of seedlings in both studied species was the highest at 1 mg/L IBA. The use of NAA in the culture medium produced roots that stuck together and were fragile in some cases, which was not suitable for the compatibility. By comparing different substrates, it was found that the use of cocopeat + perlite increased the seedling compatibility percentage to more than 95% in both species.