Construction of a bacterial artificial chromosome library of S-type CMS maize mitochondria

in order to isolate mitochondrial genes easily, we have developed a new met hod to construct S-type CMS maize mitochondrial gene library by means of em bedding mitochondria and enzymatic digesting mitochondria in situ, preparin g mtDNA by electrophoresis, digesting LMP agarose with beta -agarase, using BAC vector and electroporation. About 2 500 white clones of Mo17 CMS-J mit ochondrial gene library were obtained with the average size of 18.24 kb, ra nging from 5 to 40 kb, 63.6% inserts came from mitochondrial genome and rep resented 48 x mitochondrial genome equivalents. All the probes had detected the positive clones in the gene library. It is helpful to elucidating the maize mitochondrial genome structure and mechanism of S-type CMS, and may g ive some valuable reference to the construction of other plant mitochondria l genome library.