1.Fruit set failure in tissue culture-regenerated ‘Barhee’ palms is possibly due to many interrelated events that lead to a slow growth of pollen tube at early stage of development and that is possibly be accentuated by a relatively high abscissic acid level during this stage (Cohen et al., 2004; Alkhateeb, 2008).
2.It is well known that one of the major weaknesses of mass tissue culture propagation technique is the appearance of undesired off-type plants, such as fruit set failure, abnormal and/or delayed flowering time especially during the early flowering seasons (Zaid and de Wet, 1999; Cohen et al., 2004; Awad, 2007; Alkhateeb, 2008).