Effect of medium type, TDZ, PG, and their interactions on In Vitro Regeneration (Phoenix dactylifera L.) cv. Barhee

Abstract

Date palm micropropagation still faces many problems, such as reduced growth and development of callus and organogenesis has lower multiplication efficiency. The effect of Phloroglucinol (PG) (HA; 0, 25, 50 and 100 mg l⁻¹), and Thidiazuron (TDZ) (0.0 , 0.5 and 1.0 mg l⁻¹)  were studied on in vitro regeneration of Phoenix dactylifera L., cv. Barhee. Liquid media supplemented with 50 mg l⁻¹ PG in combination with 0.5 mg l⁻¹ TDZ gave the highest callus weight (6.94 gm). This treatment was also more effective in obtaining the highest number of buds and average shoots formation (23.0, and 41.0 ) for each of them, respectively. The liquid medium supplemented with 50 mg l^-1 PG in combination with 1.0 mg l^-1 TDZ gave the highest shoots content of nitrogen (0.867%), while the highest shoots content of phosphor and  Potassium (0.4567 % and 0.9033 %) were found in liquid media supplemented with 50 mg l^-1 PG and 0.5 mg l^-1 TDZ combination. Furthermore, we found that the combined application between 50 mg l⁻¹ PG and 0.5 mg l⁻¹ TDZ in the liquid medium. resulted in the highest shoots content of endogenous IAA levels (3.644 µg.kg⁻¹), compared with other treatments. The data revealed that the maximum chlorophyll content of shoots was observed in a medium supplemented with 50 mg l⁻¹ PG and 0.5 mg l⁻¹ TDZ with the liquid medium.