Determination of the selfing rate in a Hinoki (Chamaecyparis obtusa) seedorchard by using a chloroplast PCR-SSCP marker

摘要

The selfing rate in a Hinoki (Chamaecyparis obtusa) seed orchard, representing the most common coniferous species in Japan, was determined by using a highly specific PCR-SSCP (Polymerase Chain Reaction - Single-Strand Conformation Polymorphism) marker which recognizes the spacer region between the genes trnD and trnY of the chloroplast DNA. One-thousand and three open-pollinated offsprings were analyzed from plus tree clone YKZ5. This clone has a single point mutation in comparison with 32 wild type clones which are also present in the orchard. Among the offsprings tested, the mutant chloroplast haplotype was detected in 23 samples. Based on the paternal inheritance of the chloroplast DNA marker, the mean selfing rate of clone YKZ5 was determined to 2.3% in good agreement with the theoretical value expected. Data demonstrate that the newly-developed PCR-SSCP marker derived from chloroplast DNA provides a powerful tool for accurate and effective analyzing of gene flow within a Hinoki seed orchard.