Paternal inheritance of chloroplast DNA in Douglas-fir

Abstract

The inheritance of chloroplast DNA in Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) was determined using a restriction fragment length polymorphism (RFLP) as a marker. An insertion/deletion sequence homologous to a 15.3 kilobase PstI fragment from petunia chloroplast DNA was detected in SmaI and BamHI digests of total DNAs of parent trees. Full-sib progeny (36 in total) were then assayed for this polymorphism in three sets of crosses between male and female parents with different RFLP markers. The full-sib progeny had the same restriction fragment as the male parent, with three exceptions. These data provide direct evidence for the paternal inheritance of chloroplast DNA in a gymnosperm. This result is in sharp contrast to the strict maternal and occasional biparental inheritance of chloroplast DNA observed in angiosperms. The three exceptions had restriction fragments unlike either the male or female parents of the cross, suggesting that some type of mutational or recombinational event had occurred during the transmission of these genomes.