A comparative study on the growth characteristics of offshoot and tissue culture propagated palm trees in orchards

ABSTRACT:Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. Plant tissue culture is widely used to produce clones of a plant in a method known as micropropagation; meanwhile, observing abnormal plants is possible. Some abnormalities have been reported in date palm trees which are propagated by tissue culture. These reported abnormalities, including: Plant dwarfism, excessive vegetative growth, bleached white leaves, various color leaflet, leaf black burn, offshoot misshapenness, twisted curly inflorescence, parthenocarpic fruits production are some abnormalities that have been obsereved in the datepalm trees propagated by tissue culture method. In order to evaluate the demonstrated abnormalities in “Berhee” micropropagated and offshoot propagated datepalms, an investigation was conducted in 2009 on 20 trees originated from tissue culture propagation mehod in Jiroft area and 20 trees originated from offshoot propagation mehod in Abadan area (control) and the obtained data was analyzed and compared by T test, statitically. The evaluated characteristics in current study included: Plant dwarfism, excessive vegetative growth, bleached white leaves, various color leaflet, leaf black burn, offshoot misshapenness, twisted curly inflorescence, fruit set percentage, fruit shedding percentage, total number of primary flowers, number of seeded fruits, number of parthenocarpic fruits, total number of parthenocarpic fruits and percentage of parthenocarpic fruits. The obtained result from T-test indicated significant differences between date palm trees are propagated by offshoot and tissue culture methods. The trees derived from tissue culture in compare to trees consequent from offshoot showed much more primary flowers, but increase in number of seedless fruits or in the other hands the high percentage of parthenocarpic fruits were observed. The percentage of fruit set with seeded fruits in trees resulting from offshoot were 2-fold of fruit set of trees resultant from tissue culture. Comparing the standard deviations of all evaluated characteristics to control indicated that standard deviation in trees propagated by tissue culture was higher than trees propagated by offshoot. In the other words, high variation observed in measured characteristics of trees derived from tissue culture.