Selection of chloroplast mutants.

The chloroplast genome encodes a number of proteins, including thylakoid proteins and the large subunit of ribulose biphosphate carboxylase, associated with the structure and function of the chloroplast (1-2). In addition, many components of the chloroplast translational machinery, such as all of the RNAs and some of the ribosomal proteins, are coded by the chloroplast DNA. Although there have been numerous investigations into the genetics of algal chloroplasts, similar studies with higher plants have been hampered by the uniparental (maternal) pattern of transmission of chloroplasts observed in most species, and the shortage of suitable genetic markers (3,4).