The barriers at the post-fertilization stage occurred only in the cross ‘C/B’ leading to development of abnormal embryos but the reciprocal cross ‘B/C’ produced normal embryos in healthy seeds which gave high germination percentage and healthy seedlings thereafter. The embryos from the cross ‘C/B’ were aborted at the globular stage. The cause of embryo abortion could be due to abnormal development of endosperm leading to nutrient deficiency in the developing embryo (Barbano and Topoleski, 1984;Yoon et al., 2006). Endosperm regulates embryo development by providing nutrients (Brink and Cooper, 1947) as well as growth regulating substances or other messenger molecules (Maheshwariand Rangaswamy, 1965). Lester and Kang (1998) suggested thatin an inappropriate hybridization in Solanum species unregulatedproduction of nucleases and proteases by the endosperm causedthe autolysis of endosperm and digestion of the embryo. Therefore,it might be concluded that the inter-specific barrier between the particular cultivars used in this experiment, i.e. KKU-P11176; C.chinense Jacq. and KKU-P34021; C. baccatum L. might be overcome by using the latter as the female parent.