Adaxial side of the explant in contact with the medium significantly reduced the number of regenerants formed from leaf explants. The influence of explant orientation on in vitro regenerative responses has also been reported for other plant species. The maximum shoot regeneration in lowbush blueberry occurred in leaf segments positioned with the adaxial side touching the culture medium (Debanath, 2009). In Primulina tabacum, leaf explants cultured with adaxial surface in contact with the medium induced more somatic embryos or shoots than when the abaxial surface placed on the medium ( Ma et al., 2010). However, leaf explants of Crepis novoana showed better response when placed with abaxial surface in contact with the media ( Corral et al., 2011). The influence of abaxial or adaxial orientation of leaf explants on plant regeneration in culture may result from cellular organization, degree of compactness, and structure and number of stomata which can influence uptake and transport of nutrients and growth regulators as well as degree of exposure to light.