Interspecific hybridization in kenaf (Hibiscus cannabinus L.): barriers and potential

Interspecific hybridization has emerged as a proven technology for genetic base broadening and transfer of specific traits in many crop species. However, its utilization in crop breeding programme of kenaf (Hibiscus cannabinus), an important fibre crop is limited due to reproductive barriers between cultivated and wild species. Mechanism of hybridization barrier was investigated in incompatible and compatible crosses of kenaf and a number of wild relatives which revealed that pre-fertilization barriers significantly reduce the chance of cross-species fertilization. Stylar inhibition was accomplished by deposition of callose in pollen tube. Callose inhibition was incremental retarding pollen tube growth and development. Among the post-fertilization barriers death of immature embryo significantly reduced seed set. The potential of interspecific hybridization in kenaf is discussed in the light of genetic relatedness of kenaf and its wild relatives.