Incomplete paternal inheritance of chloroplast DNA recognized in Chamaecyparis obtusa using an intraspecific polymorphism of the trnD-trnY intergenicspacer region

Using a fluorescence-based PCR-SSCP (single-strand conformation polymorphis m), we verified imperfectibility in the paternal inheritance of chloroplast DNA (cpDNA) in Chamaecyparis obtusa (Cupressaceae) controlled crosses. An intraspecific sequence poly morphism of the intergenic spacer region betwee n the trnD and trnY genes was utilized as a molecular marker. Of 361 progen ies, in which the cpDNA haplotypes of their female and male parents were di fferent, 352 (97.5%) possessed the same haplotypes as their male parents, a nd nine (2.5%) the same haplotypes as their female parents. The parentage o f the nine progenies with female parental types was diagnosed using DNA fin gerprinting based on fluorescence-based RAPD profiles. Their parentage show ed convincing evidence of the low frequency of maternal inheritance. Moreov er, heteroplasmy was observed in the open-pollinated seeds collected in a s eed orchard. The confirmation of maternal plastid transmission in the full- sib families and the observation of heteroplasmy in seeds reveal that the p aternal inheritance of cpDNA is not an exclusive phenomenon and that the mo de of its inheritance is biparental in C. obtusa.