Investigation of the effect of various sterilization procedures for successful callus and shoot proliferation of Tamarix aphylla

Tamarix aphylla is used as a windbreaker, shade tree and ornamental plant in gardens and urban landscape. The browning phenomenon is an important inhibitory factor in various stages such as disinfection and regeneration of Tamarix aphylla. To optimize the disinfection conditions and control the browning process of the explants, experiments were carried out with disinfectants and eugenol compound to disinfect the current and annual stem explants. Then, callus induction was studied in a medium complemented by two types of auxins (2,4-D and NAA). In the third experiment, the optimization of shoot induction medium was investigated on current and one year old shoots explants. The best disinfection treatment to control fungal and bacterial contamination and phenol secretion from the current explants was obtained using a 60-second ethanol application combined with 10 minutes of 20% sodium hypochlorite disinfection. Spraying of donor plants with thiophanate methyl fungicide was also able to reduce fungal contamination by almost 50% compared to the control. Application of 0.01% eugenol in the medium by injection reduced the contamination and phenol secretion from the explants. The highest survival and callus induction was acquired at the concentration of 1 mgL-1 2, 4-D, in the shortest time. Shoot induction in the explants of current and one year old shoots was obtained in the culture medium containing 2 mgL-1 BA and 0.5 mgL-1 IBA In conclusion, the application of younger plant materials, spraying of donor plant with fungicides and the use of 0.01% eugenol in the medium can reduce the browning phenomenon and proper control of contamination and finally could provide micropropagation of Tamarix aphylla shrubs using appropriate growth regulators