Joseph  has combined his training in Forestry at B.Sc level (Moi University, Kenya) with post-graduate training in Cell Biology (Ph.D., University of Natal, Durban) to pursue research on aspects of seed biology and plant germplasm conservation. He has been involved in this research for 15 years, and his interests include the post-shedding behaviour of non-orthodox (desiccation-intolerant and/or, short-lived) seeds, and the development of in vitro and cryopreservation techniques for the long-term conservation of the germplasm of plants producing such seeds. He is also working on the cryopreservation of the germplasm of plants that are propagated mainly vegetatively, or for which sexual reproduction is undesirable – for example, specific genotypes. Plant cell biology is central to his research, and includes the use of techniques such as electron and light microscopy, in order to understand the basis of the response various plant tissues and explants to post-shedding stresses, and to treatments involved in cryopreservation.