Table 2 DNA methods for identification of Panax species

Six Panax species and adulterants

ITS1-5.8S-ITS2 sequences

The polymorphisms in the ITS1-5.8S-ITS2 sequence among the samples can be shown using various restriction enzymes to create species-specific RFLP profiles. Ten per cent of contamination of P. ginseng was detected from P. quinquefolius sample.

Three Panax species

18S sequences

Based on the 18S rRNA gene, three Panax species gave species-specific electrophoretic profiles by PCR-RFLP and expected fragments corresponding to each species were detected only under defined conditions by mutant allele specific amplification (MASA, i.e. ARMS) analyses.

P. ginseng from four localities, one from China and three from Korea

18S sequences

A ginseng sample showed fragments distinctive from the other two samples of the same country but different locality origins.

P. ginseng and P. quinquefolius

no

Polymorphic bands unique to P. ginseng and to P. quinquefolius and bands common to them were identified. P. ginseng samples from different farms in China and Korea are homogeneous genetically. P. quinquefolius from different sources are much more heterogeneous.

P. ginseng from four localities, one from China and three from Korea

no

Similarity among the DNA of ginseng plants analyzed was low.

Three strains of P. ginseng

no

A 725 bp band was present in the elite strain Aizu K-111 (now called Kaishusan) while the other strains did not always show this band.

Two cultivated groups of ginseng

no

Cluster analysis of the patterns showed that the genetic relationship between different strains of Da-maya group is closer than those strains of E-maya group.

Three Panax species and adulterants

no

Fingerprints for P. ginseng or P. quinquefolius were basically consistent irrespective of plant source or age compared to the very different fingerprints from adulterants. The degree of similarity of the fingerprints confirmed that P. ginseng is more closely related to P. quinquefolius than it is to P. notoginseng.

Oriental ginseng from two sources and two American ginseng

no

Oriental ginseng from two sources produced nearly identical fingerprints. Two American ginseng samples gave fingerprints distinctive to the species with two primers tested but polymorphic and significantly different fingerprints with one of the primers tested. Therefore, the American ginseng samples were supposed to be from different strains.

P. ginseng and P. quinquefolius

no

A DALP fragment was found present in all P. ginsengs but absent in all the P. quinquefolius examined. The species-specific band was converted to sequence-tagged site (i.e. amplification by specific primers giving a species-specific band) for quick authentication.

P. ginseng and P. quinquefolius

polymorphic AFLP band

A polymorphic AFLP band in P. ginseng contains a minisatellite which can be used in DAMD analysis to authenticate the two tested ginsengs.

Two Panax species and adulterants

polymorphic RAPD fragment

There is a 25 bp insertion in P. ginseng for a polymorphic RAPD fragment. By using primers designed based on this polymorphic fragment, P. quinquefolius and P. ginseng can be differentiated. Amplification on four other Panax species and two ginseng adulterants gave markedly different products.

Five Panax species and corresponding Ginseng drugs

trnK and nuclear 18S gene sequences

Five sets of species-specific primers with two pairs in each set were designed. Two expected fragments, one from trnK gene and another from 18S rRNA gene, were observed simultaneously only when the set of species-specific primers encountered template DNA of the corresponding species.

Two Panax species

primer sequences for the loci

Using nine of the 16 screened loci, Chinese ginseng was differentiated unambiguously from the American samples. Some of the informative loci showed different allelic patterns among ginsengs from different farms.

American ginseng and Oriental ginseng, cultivated and wild American ginseng

primer sequences for the loci

American ginseng had a different allele pattern (allele frequency in an American ginseng population of 34 cultivated and 21 wild ginseng) in two microsatellite loci compared with that of the Oriental ginseng (six from China and South Korea). Cultivated and wild American ginseng were distinguished.

Three Panax species

primer sequences for 18S region

The sequences of the 18S rRNA region of 3 Panax species have different base substitutions at four nucleotide positions. By the polymorphism, the ginseng species from commercial samples were identified.

Twelve Panax species

primer sequences for ITS and 5.8S regions

The sequences of the ITS and 5.8S coding region were used to reconstruct the phylogenetic relationships among twelve Panax species. P. quinquefolius was suggested to be more closely related to the eastern Asian species than P. trifolius. Previous suggestions about monophyly of P. ginseng, P. notoginseng and P. quinquefolius were not supported by the ITS data. Several biogeographical implications were inferred from the results.

Panax notoginseng of different cultivar origins

primer sequences for 18S and matK genes

The nuclear 18S rRNA and chloroplast matK genes of 18 samples of Panax notoginseng and its processed material Sanqi (Radix Notoginseng) were found to be identical regardless of cultivar origin. Thus the same strain should be used in cultivation for conservation of the species.

P. notoginseng and adulterants

primer sequences for 18S and matK genes

Notoginseng and its adulterants were differentiated on the basis of their sequence variation in the nuclear ribosomal RNA small subunit (18S rRNA) and chloroplast matK gene.

Two Panax species and adulterants

primer sequences for ITS and rbcL genes

The nuclear ITS and chloroplast rbcL regions were amplified using universal primers and then sequenced using nested ginseng-specific primers. All the samples including five root samples, thirteen powder samples and six capsule samples were identified as American or Korean ginseng except a capsule and a tablet that were identified as soybean, by using the universal primers for sequencing. They could not be sequenced by the nested primers.