The microstructure observation of seed surface structure is needed for protocols of breaking dormancy of seeds with physical dormancy. The seeds of Rubus species are surrounded by a thick, hard endocarp; together, the seed and endocarp make up the stone. We evaluate stone characteristics of 18 species of Rubus through optical microscopic observation, and correlate different stone characteristics with endocarp thickness. As a result of stone size comparison, Rubus species were classified as big stones group including R. parvifolius and R. idaeus, small stones group including R. longisepalus var. longisepalus, R. corchorifolius and R. hirsutus, and middle stones group including rest of the species. The result of this study revealed that stone size and the endocarp thickness in Rubus species was various characteristics in each species. Furthermore stone size and stone weight were also well correlated endocarp thickness and result indicated that heavy stones had harder endocarp than lighter one. Thus from the result of this study it can be presumed that only one stone characteristic approach may be sufficient to estimate other characteristics in Rubus.

Background : Bokbonja the Korean black raspberry (Rubus coreanus Miquel) fruit derived product, which is native to Korea. They contain potential anti-aging, anti-oxidants, depurative activities. Bokbonja refers to an immature berry of Rubus coreanus in the Korean pharmacopeia, Rubus chingii in Chinese pharmacopeia. Recently several Rubus species are available in the Korean drug markets which could easily find their way into drug prescriptions. Methods and Results : Hence we tried to detect the presence of these contaminating species in bokbonja products using SNP marker assisted by multi-plex PCR. We found a SNP region in the 26S region of these species and evaluated their potential to discriminate Rubus species. We designed a set of primer pairs such as, BokR primer has distinguished R.coreanus by producing a band at 852 bp and the primer sanF has differentiated R. crataegifolius by amplifying a band at 129 bp, while chiF has produced a band at 83 bp to distinguish R.chingii. These primer pairs effectively distinguished the bokbonja samples collected from various local markets as well as form drug store in Korea as well. The results were shocking as the bokbonja (R.coreanus) has a limited usage in Korea and either R. crataegifolius or R.chingii has been found in these samples. Taken together the primer pairs bokR, sanF, chiF along with 26S universal primers could effectively distinguish Rubus species in a single multiplex PCR reaction. Conclusion : Our results based on the 26S rDNA derived SNP region have shown that, the usage of R. coreanus is extremely limited and its often mistaken or adulterated with R. crataegifolius and R. chingii. It presses a panic situation in Korean peninsula to preserve bokbonja and the species R.coreanus which is endemic and superior in efficacy.

The genus Rubus belongs to the Rosaceae family and is comprised of 600-800 species distributed worldwide. Understanding the genetic relationships and genetic structure in Rubus species is important for enabling efficient management, conservation, characterization and utilization of the species. However, as a minor crop, genetic research foundation was limited to explore genetic diversity and relationships in Rubus species. The present study shows the results of application SSR markers that were developed from SSR-enriched libraries of the one Rubus species (Rubus coreanus Mique.) in our previous study. We used 34 polymorphic microsatellite markers to analysis of genetic diversity within the Rubus species, including redraspberry, blackraspberry, blackberry and mountainberry. All the 34 SSR primers pairs produced 483 polymorphic and reproducible amplification fragments. The largest number of alleles per primer pair was confirmed at GB-RC-167, GB-RC-100, GB-RC-076 and GB-RC-245, which contained 26, 25, 23 and 21, respectively. An average value of polymorphic information contents (PIC) were 0.74 with a range of 0.36 to 0.92. Population structure and phylogenetic analyses showed that all Rubus species formed three largely distinct clusters, which were confirmed by principal coordinate analysis (PCoA). We obtained the results that the developed SSR markers showed a substantial degree of genetic diversity in the various Rubus species distributed in Korea.

There is a considerable difference in morphological traits between Bokbunja cultivated in Korea (KCB) and Korea native Rubus coreanus, contrary to the conviction that the cultivated Bokbunja is the domestication of R. coreanus. To infer the phylogenetic relationship of KCB with other Rubus species, we compared the chloroplast DNA spacers of KCB with those of several Rubus species including black raspberry, R. occidentalis. The three chloroplast DNA spacers, atpB~rbcL, trnL~trnF, and trnT~trnL, were amplified using the specific primer pairs and converted to Single Strand Conformational Polymorphism (SSCP) markers. The SSCP makers of the chloroplast DNA spacers showed a considerable variation both within and among Rubus species. In the phylogenetic tree generated by the SSCP markers, KCB accessions were located in the same clade with R. occidentalis, but R. coreanus accessions in the different clade. Also, in the phylogenetic tree by the nucleotide sequences of the chloroplast DNA spacer trnL~trnF, KCB located in the same clade with R. occidentalis but not with R. coreanus. These results suggest that the three KCB accessions share higher similarity with R. occidentalis than with R. coreanus in the three chloroplast DNA spacers.

The bramble cultivated widely in South Korea, which is known as Bokbunja-ddal-gi, is regarded as having originated from Korean native Rubus coreanus. This study was carried out to obtain basic phylogenetic information on Korean cultivated bramble (KCB) by comparing the internal transcribed spacer (ITS) regions with those of R. coreanus, blackberry (R. lanciniatus), black (R. occidentalis) and red (R. idaeus) raspberry. Sequences of the ITS 1 suggest that some KCB accessions share a significant similarity with both R. occidentalis and R. coreanus in the ITS 1 region. The ITS 2 sequences of the three KCB accessions clustered more closely to those of two R. occidentalis accessions than to those of R. coreanus. These results suggest that there exist variations in the sequences of ITS among KCB accessions and KCB accessions are more closely related to black raspberry than R. coreanus in the ITS regions.

The plant Rubus species (Rosaceae) mainly contains 19α-hydroxyurane-type triterpenoids (19α-HUT) as bioactive components. Available functional food includes blackberry (the fruit of thornless Rubus sp.), red raspberry (R. idaeus) and black raspberry (R. occidentalis). However, the fruit of R. coreanus, which is used in Korea as a functional food, substitutes black raspberry. Rubi Fructus, which has been traditionally used as an oriental medicinal drug, designates only unripe fruit of R. coreanus but not its ripe fruit which indicates that it needs high content of 19α-HUT as a crude drug. Throughout our experiment, we found that ripe fruits contain very little amount of 19α-HUT when compared to unripe fruits. In addition, various and rich 19α-HUT has been reported from Rubus species. The most common structure of 19α-HUT of Rubus species, euscaphic acid or tormentic acid with 3α-OH or 3β-OH, respectively, can be glycosylated or oxidized to produce a number of 19α-HUTs as euscaphic acid and tormentic acid derivatives and even esterified to form dimeric triterpenoids. In this review, the bioactivity and biosynthetic pathway and chemical characterization of 19α-HUTs found in Rubus species are discussed.