Genetic Characterization of Flowering Cherries (Prunus subgenus Cerasus) Using rp116-rp114 Spacer Sequences of Chloroplast DNA

Abstract

Genetic variations among flowering cherries (Prunus subgenus Cerasus) were analyzed by spacer sequences between ribosomal protein L16 (rpl16) and ribosomal protein L14 (rpl14) genes of chloroplast DNA, these sequences were named plastid subtype ID (PS-ID), by using a total of 40 individuals from 11 species and 3 cultivars. Nucleotide sequences of ca. 420 bp were identified as part of rpl16 gene and PS-ID regions. One mutation site was found in partial nucleotide sequences of rpl16 gene. Five different A-repeat types were found at PS-ID region, which were denoted as 9A-T-10A, 10A-T-9A, 13A, 14A, and 15A, respectively. One base change also existed in the downstream of A-repeat. Many individuals (20/22) in species that originated from Japan, except for P. pendula f. ascendens, were 14A type, whereas all 9 individuals of P. pendula f. ascendens were 10A-T-9A type. Therefore, the maternal line of cultivars related to P. pendula f. ascendens can be revealed by the analysis of PS-ID region. In addition, P. pendula f. ascendens differs from other Japanese taxa based on morphological traits. The difference is supported from the nucleotide sequences of PS-ID in this study. The A-repeat types of cultivars, i.e., ‘Someiyoshino’, ‘Ichiharatoranoo’, and ‘Shirotae’, were 10A-T-9A type, 14A type, and 14A type, respectively, which suggests that the female parent of the ‘Someiyoshino’ was P. pendula f. ascendens. The results of ‘Ichiharatoranoo’ and ‘Shirotae’ analyses were not contradictory to the morphological taxonomy. PS-ID region was highly variable and useful for evaluating genetic variation and elucidating the origin of cultivars.