Essential Hormonal Conditions for Callus Production and Growth in the Stem Explants of Tehran Pine (Pinus eldarica M.)

Callus production potential and callus growth rate in the stem explants of five to 6-year-old Tehran pine (Pinus eldarica M.) were investigated in 30 different treatments of MMS culture medium. The experiment was carried out as a completely randomized design. Rusults showed significant difference between treatments at % probability level for the amount of callus produced. In addition results indicated that 2,4-D is an essential component for stimulation of callus production and is more effective than NAA. The increase of this hormone to the concentration level of 7.5 mg lit-1, caused increase in callus production but the growth rate of the callus in subsequent subcultures was higher in lower concentrations of this hormone. Furthermore, analysis of the callus growth data using multivariate regression showed a negative interaction between the concentration of 2,4-D and kinetin, since the increase in 2,4-D concentration caused more callus growth while at the presence of high kinetin concentration the lower growth in the callus was observed. However, this interaction between NAA and kinetin was not obtained.