Overcoming cross incompatibility between nicotiana tabacum L. and N. trigonophylla Dun. through in vitro fertilization

Interspecific hybrids between Nicotiana tabacum L. (2n=48, ♀) and N. trigonophylla Dun. (2n=24, ♂) can not be obtained by conventional crossing because of the existance of strong sexual prefertilization barries. The technique of in vitro fertilization were applied to overcome this cross incompatibility. Ten placenta with intact ovules of N. tabacum were pollinated in vitro. by dusting pollen grains of N. trigonophylla. Finally, seven hybrid plants were obtained. All of the hybrid plants were morphological uniform and had 36 chromosomes which were additive sum of the haploid chromosomes of the parents. From the results, it is considered that the in vitro fertilization is useful for overcoming sexual prefertilization barriers.