# Application of Partial Internal Transcribed Spacer Sequences for the Discrimination ofArtemisia capillaris from OtherArtemisia Species

Authors: Eui Jeong Doh; Seung-Ho Paek; Guemsan Lee; Mi-Young Lee; Seung-Eun Oh
Journal: Evidence-Based Complementary and Alternative Medicine
 (2016)

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## Abstract

SeveralArtemisia species are used as herbal medicines including the dried aerial parts ofArtemisia capillaris, which are used as Artemisiae Capillaris Herba (known as “Injinho” in Korean medicinal terminology and “Yin Chen Hao” in Chinese). In this study, we developed tools for distinguishing betweenA. capillaris and 11 otherArtemisia species that grow and/or are cultured in China, Japan, and Korea. Based on partial nucleotide sequences in the internal transcribed spacer (ITS) that differ between the species, we designed primers to amplify a DNA marker forA. capillaris. In addition, to detect otherArtemisia species that are contaminants ofA. capillaris, we designed primers to amplify DNA markers ofA. japonica,A. annua,A. apiacea, andA. anomala. Moreover, based on random amplified polymorphic DNA analysis, we confirmed that primers developed in a previous study could be used to identifyArtemisia species that are sources of Artemisiae Argyi Folium and Artemisiae Iwayomogii Herba. By using these primers, we found that multiplex polymerase chain reaction (PCR) was a reliable tool to distinguish betweenA. capillaris and otherArtemisia species and to identify otherArtemisia species as contaminants ofA. capillaris in a single PCR.


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## Body

## 1. Introduction

The genusArtemisia belongs to the Asteraceae family and is composed of 500 species that are mainly found in Asia, Europe, and North America [1, 2]. Over 350 species in the genusArtemisia are grown in Asia, including China, Korea, and Japan [1]. SeveralArtemisia species have long been used for the treatment of disease in modern and traditional medicine [2, 3]. For example, the dried aerial parts ofA. capillaris are used as Artemisiae Capillaris Herba (“Injinho” in Korean medicinal terminology and “Yin Chen Hao” in Chinese) [4], which controls fever [2], protects the liver [5], and inhibits inflammatory responses [6]. However, the dried leaves ofA. capillaris are often mistaken for those ofA. japonica. Moreover, youngA. capillaris leaves that are harvested in early spring are similar to those ofA. argyi andA. princeps [7], which are sources of Artemisiae Argyi Folium (“Aeyup” in Korean and “Ai Ye” in Chinese) that is used for the treatment of pain, vomiting, and bleeding in the uterus [8].Because of the morphological similarities among the dried and/or sliced shoots and leaves ofArtemisia species, some are traded as other species in traditional herbal medicine markets [5, 7]. To resolve this problem, various molecular biology techniques that are based on plant genetic information, such as gene nucleotide sequences (rbcL,matK, or a combination of both), have been used for plant identification and authentication, including medicinal plants [3]. Other gene sequences have been used to discriminate specific medicinal plants from an adulterant or substitute, for example, thetrnL-F intergenic spacer forCoptis spp.,matK forRheum spp., andpsbA-trnH forPhyllanthus spp. [9–11]. Internal transcribed spacer (ITS) sequences are effective discriminatory tools, and the ITS2 region in particular can be used as a universal DNA barcode for identifying plants and animals [12], including medicinal plants in the family Fabaceae [13] and genusArtemisia [14].Random amplified polymorphic DNA- (RAPD-) based DNA markers have been used previously for authenticating medicinal plants [3]. In a previous study conducted on sixArtemisia species that mainly grow and/or are cultured in Korea (A. princeps,A. argyi,A. capillaris,A. iwayomogi,A. japonica, andA. keiskeana), we discriminated bothA. princeps andA. argyi from otherArtemisia species using a sequence-characterized amplified region (SCAR) marker, which was based on RAPD results [7]. Using the same method, we identifiedA. iwayomogi, which is a source of Artemisiae Iwayomogii Herba (“Haninjin” in Korean medicinal terminology) that has been prescribed as a substitute for Artemisiae Capillaris Herba in Korea [15]. However, we were unable to discriminateA. capillaris fromA. japonica using the RAPD-based method [5, 7].In this study, we discriminatedA. capillaris from otherArtemisia species, particularlyA. japonica, by exploiting sequence differences in a specific region of the ITS. We used 12Artemisia species, six from our previous study and 6 additionalArtemisia species, which grow and/or are cultivated in China, Korea, and Japan:A. asiatica,A. montana, andA. lavandulaefolia, which are sources of Artemisiae Argyi Folium in China and Korea [4, 16, 17];A. annua andA. apiacea, which are sources of Artemisiae Annuae Herba (“Chung-ho” in Korean medical terminology and “Qing Hao” in Chinese) [4, 18] used for the treatment of malaria [19]; andA. anomala, which is a source of Artemisiae Anomalae Herba (“Yugino” in Korean medicinal terminology and “Liu ji nu” in Chinese) [4, 17] used for the treatment of fever and inflammation [20].A. anomala was included to increase the reliability of the discrimination ofA. capillaris. In addition, we tested the effectiveness of multiplex polymerase chain reaction (PCR) to detect contamination ofA. capillaris products with those from otherArtemisia species. We used primers based on ITS sequences to discriminate among theArtemisia species and two RAPD-based primer sets to discriminate betweenArtemisia species that are sources of Artemisiae Argyi Folium and Artemisiae Iwayomogii Herba [5, 7].


## 2. Materials and Methods

### 2.1. Plant Materials

The fleshy aerial parts, including the leaves, ofArtemisia species that grow and/or are cultivated in China, Korea, and Japan were collected (Table 1). The samples were dried at room temperature, frozen, and stored at −80°C. The authenticity of the samples was verified by the Korea Institute of Oriental Medicine (KIOM) and the Department of Herbology, Wonkwang University. The voucher samples were deposited in the KIOM and the Department of Herbology.Table 1
Artemisia plants used to determine the internal transcribed spacer (ITS) sequence.
Number
Medicinal name
Name of the plant species
Place of collection
Voucher number
1
Artemisiae Argyi Folium
A. asiatica
Bonghwa, Korea
WKUARE04
2
WKUARE24
3
WKUARE25
4
A. montana
Kyoto, Japan
WKUARE76
5
WKUARE77
6
WKUARE78
7
Jeonju, Korea
WKUARE40
8
WKUARE41
9
A. lavandulaefolia
Sichuan, China
WKUARE66
10
WKUARE57
11
WKUARE58
12
WKUARE67
13
A. argyi
Suwon, Korea
WKUARE05
14
WKUARE06
15
WKUARE30
16
WKUARE31
17
Guangxi, China
WKUARE27
18
Sichuan, China
WKUARE59
19
A. princeps
Jeonju, Korea
WKUARE43
20
WKUARE44
21
WKUARE45
22
Uiseong, Korea
WKUARE01
23
Ganghwa, Korea
WKUARE55
24
WKUARE56
25
Artemisiae Capillaris Herba
A. capillaris
Suwon, Korea
WKUARE33
26
WKUARE34
27
Jeonju, Korea
WKUARE35
28
WKUARE46
29
WKUARE47
30
Nishi, Japan
WKUARE79
31
WKUARE80
32
Sichuan, China
WKUARE52
33
Artemisiae Iwayomogii Herba
A. iwayomogi
Suwon, Korea
WKUARE37
34
Jinan, Korea
WKUARE10
35
Pohang, Korea
WKUARE68
36
WKUARE69
37
Jeonju, Korea
WKUARE11
38
WKUARE48
39
WKUARE49
40
Artemisiae Annuae Herba
A. annua
Namwon, Korea
WKUARE20
41
Yeongcheon, Korea
WKUARE21
42
Sichuan, China
WKUARE60
43
WKUARE61
44
WKUARE62
45
A. apiacea
Sichuan, China
WKUARE63
46
WKUARE53
47
WKUARE54
48
Nishi, Japan
WKUARE81
49
WKUARE82
50
Artemisiae Anomalae Herba
A. anomala
Sichuan, China
WKUARE64
51
WKUARE65
52
Pohang, Korea
WKUARE73
53
WKUARE74
54
WKUARE75
55
Artemisiae Japonicae Herba
A. japonica
Suwon, Korea
WKUARE39
56
Jeonju, Korea
WKUARE50
57
WKUARE51
58
Namryung, China
WKUARE17
59
Nishi, Japan
WKUARE83
60
WKUARE84
61
Artemisia Keiskeanae Herba
A. keiskeana
Suwon, Korea
WKUARE16
62
Uiseong, Korea
WKUARE15
63
Pohang, Korea
WKUARE70
64
WKUARE71
65
WKUARE72


### 2.2. Preparation of Genomic DNA

Genomic DNA from each sample was extracted in accordance with the instruction manual for the NucleoSpin® Plant II (Macherey-Nagel, Duren, Germany). To improve DNA quality, phenolic compounds and polysaccharides were removed using 10% cetyltrimethylammonium bromide and 0.7 M NaCl. After the purity and amount of the prepared genomic DNA were determined using a NanoDrop™ DN-1000 spectrophotometer (Thermo Scientific, Wilmington, DE, USA), the DNA was diluted to 10 ng/μL and stored.


### 2.3. PCR Amplification

#### 2.3.1. Amplification of ITS

A PCR for the amplification of the ITS, including the 5.8S rRNA coding region, was conducted using a T-personal cycler (Biometra, Goettingen, Germany) according to the protocol by White et al. [21]. In brief, 1.2 pmol of ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) primers, 1 UTaq polymerase (ABgene, Epsom, UK), and 20 ng of genomic DNA extracted from each sample were used for the PCR amplification. During the 35-cycle PCR process, predenaturation was conducted for 5 min at 95°C and denaturation for 30 s at 95°C. The annealing process was conducted for 30 s at 52°C and the extension process for 1 min at 72°C. A final reaction step was conducted for 7 min at 72°C. The amplified products were separated on 1.2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich, St. Louis, MO, USA). The amplified PCR products were analyzed using MyImage (Seoulin Biotechnology, Seoul, Korea) and purified using a LaboPass™ Gel Kit (Cosmo Genetech, Seoul, Korea).


#### 2.3.2. Amplification of DNA and SCAR Markers

In brief, 1.2 pmol of primers, 1 UTaq polymerase (ABgene), and 50 ng of genomic DNA extracted from eachArtemisia species were used for the PCR amplification. During the 23-cycle PCR process, predenaturation was conducted for 5 min at 95°C and denaturation for 30 s at 95°C. In general, the annealing process was conducted for 30 s at 53.5°C for the amplification of the DNA markers. However, to amplify the DNA markers forA. capillaris,A. japonica,A. apiacea,A. annua, andA. anomala, this process was conducted for 15–30 s at 54–58°C. The extension process was conducted for 20 s (except forA. apiacea, which had 30 s) at 72°C, and a final reaction step was conducted for 5 min at 72°C. To amplify an internal standard for the evaluation of the PCR conduct, a primer set (AYF/AYR) was used to amplify a 94 bp sequence. The amplified products were separated on 1.2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich). The amplified PCR products were then analyzed using MyImage (Seoulin Biotechnology).


#### 2.3.3. Multiplex PCR

For the multiplex PCR amplification, 0.07 pmol of the primers Fb and R7; 0.14 pmol of the primers AYF and AYR; 0.7 pmol of the primer Aam F3; 1.7 pmol of the primers AC F4, ACJ R3, and Aap R2; 3.4 pmol of the primers 2F1, 2F3, AJ F1, AC R3, Aap F1, AA F3, and Aa R4; 1x PrimeSTAR® Max DNA Polymerase (Takara Bio Inc., Kusatsu, Japan); and 20 ng of genomic DNA extracted from eachArtemisia species were used. During the 30-cycle PCR process, predenaturation was conducted for 10 min at 95°C and denaturation for 10 s at 95°C. The annealing process was conducted for 5 s at 56.5°C and the extension process for 10 s at 72°C. A final reaction step was conducted for 7 min at 72°C. The amplified products were separated on 2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich). In order to amplify an internal standard for the evaluation of the PCR, the AYF/AYR primer set was used to amplify a 94 bp sequence. The amplified PCR products were then analyzed using MyImage (Seoulin Biotechnology).


### 2.4. Nucleotide Sequencing of the PCR Products

The nucleotide sequences of the PCR products were directly determined using the primers ITS1 and ITS4 by Macrogen (Seoul, Korea). In other cases, the PCR products resolved by agarose electrophoresis were cloned using a pGEM®-T Easy Vector System I (Promega, Madison, WI, USA). The nucleotide sequences of the subcloned PCR products were determined by Macrogen.


### 2.5. Alignment of the DNA Sequences and Construction of a Dendrogram

The DNA sequences were manually edited and aligned by ClustalW multiple sequence alignment in BioEdit v7.0.9 (http://www.mbio.ncsu.edu/BioEdit/bioedit.html). A dendrogram was constructed using the neighbor-joining method [22] in the MEGA6 program [23] with 1000 bootstrap iterations. Evolutionary distances were computed using the maximum composite likelihood method [24] in MEGA6.


## 2.1. Plant Materials

The fleshy aerial parts, including the leaves, ofArtemisia species that grow and/or are cultivated in China, Korea, and Japan were collected (Table 1). The samples were dried at room temperature, frozen, and stored at −80°C. The authenticity of the samples was verified by the Korea Institute of Oriental Medicine (KIOM) and the Department of Herbology, Wonkwang University. The voucher samples were deposited in the KIOM and the Department of Herbology.Table 1
Artemisia plants used to determine the internal transcribed spacer (ITS) sequence.
Number
Medicinal name
Name of the plant species
Place of collection
Voucher number
1
Artemisiae Argyi Folium
A. asiatica
Bonghwa, Korea
WKUARE04
2
WKUARE24
3
WKUARE25
4
A. montana
Kyoto, Japan
WKUARE76
5
WKUARE77
6
WKUARE78
7
Jeonju, Korea
WKUARE40
8
WKUARE41
9
A. lavandulaefolia
Sichuan, China
WKUARE66
10
WKUARE57
11
WKUARE58
12
WKUARE67
13
A. argyi
Suwon, Korea
WKUARE05
14
WKUARE06
15
WKUARE30
16
WKUARE31
17
Guangxi, China
WKUARE27
18
Sichuan, China
WKUARE59
19
A. princeps
Jeonju, Korea
WKUARE43
20
WKUARE44
21
WKUARE45
22
Uiseong, Korea
WKUARE01
23
Ganghwa, Korea
WKUARE55
24
WKUARE56
25
Artemisiae Capillaris Herba
A. capillaris
Suwon, Korea
WKUARE33
26
WKUARE34
27
Jeonju, Korea
WKUARE35
28
WKUARE46
29
WKUARE47
30
Nishi, Japan
WKUARE79
31
WKUARE80
32
Sichuan, China
WKUARE52
33
Artemisiae Iwayomogii Herba
A. iwayomogi
Suwon, Korea
WKUARE37
34
Jinan, Korea
WKUARE10
35
Pohang, Korea
WKUARE68
36
WKUARE69
37
Jeonju, Korea
WKUARE11
38
WKUARE48
39
WKUARE49
40
Artemisiae Annuae Herba
A. annua
Namwon, Korea
WKUARE20
41
Yeongcheon, Korea
WKUARE21
42
Sichuan, China
WKUARE60
43
WKUARE61
44
WKUARE62
45
A. apiacea
Sichuan, China
WKUARE63
46
WKUARE53
47
WKUARE54
48
Nishi, Japan
WKUARE81
49
WKUARE82
50
Artemisiae Anomalae Herba
A. anomala
Sichuan, China
WKUARE64
51
WKUARE65
52
Pohang, Korea
WKUARE73
53
WKUARE74
54
WKUARE75
55
Artemisiae Japonicae Herba
A. japonica
Suwon, Korea
WKUARE39
56
Jeonju, Korea
WKUARE50
57
WKUARE51
58
Namryung, China
WKUARE17
59
Nishi, Japan
WKUARE83
60
WKUARE84
61
Artemisia Keiskeanae Herba
A. keiskeana
Suwon, Korea
WKUARE16
62
Uiseong, Korea
WKUARE15
63
Pohang, Korea
WKUARE70
64
WKUARE71
65
WKUARE72


## 2.2. Preparation of Genomic DNA

Genomic DNA from each sample was extracted in accordance with the instruction manual for the NucleoSpin® Plant II (Macherey-Nagel, Duren, Germany). To improve DNA quality, phenolic compounds and polysaccharides were removed using 10% cetyltrimethylammonium bromide and 0.7 M NaCl. After the purity and amount of the prepared genomic DNA were determined using a NanoDrop™ DN-1000 spectrophotometer (Thermo Scientific, Wilmington, DE, USA), the DNA was diluted to 10 ng/μL and stored.


## 2.3. PCR Amplification

### 2.3.1. Amplification of ITS

A PCR for the amplification of the ITS, including the 5.8S rRNA coding region, was conducted using a T-personal cycler (Biometra, Goettingen, Germany) according to the protocol by White et al. [21]. In brief, 1.2 pmol of ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) primers, 1 UTaq polymerase (ABgene, Epsom, UK), and 20 ng of genomic DNA extracted from each sample were used for the PCR amplification. During the 35-cycle PCR process, predenaturation was conducted for 5 min at 95°C and denaturation for 30 s at 95°C. The annealing process was conducted for 30 s at 52°C and the extension process for 1 min at 72°C. A final reaction step was conducted for 7 min at 72°C. The amplified products were separated on 1.2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich, St. Louis, MO, USA). The amplified PCR products were analyzed using MyImage (Seoulin Biotechnology, Seoul, Korea) and purified using a LaboPass™ Gel Kit (Cosmo Genetech, Seoul, Korea).


### 2.3.2. Amplification of DNA and SCAR Markers

In brief, 1.2 pmol of primers, 1 UTaq polymerase (ABgene), and 50 ng of genomic DNA extracted from eachArtemisia species were used for the PCR amplification. During the 23-cycle PCR process, predenaturation was conducted for 5 min at 95°C and denaturation for 30 s at 95°C. In general, the annealing process was conducted for 30 s at 53.5°C for the amplification of the DNA markers. However, to amplify the DNA markers forA. capillaris,A. japonica,A. apiacea,A. annua, andA. anomala, this process was conducted for 15–30 s at 54–58°C. The extension process was conducted for 20 s (except forA. apiacea, which had 30 s) at 72°C, and a final reaction step was conducted for 5 min at 72°C. To amplify an internal standard for the evaluation of the PCR conduct, a primer set (AYF/AYR) was used to amplify a 94 bp sequence. The amplified products were separated on 1.2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich). The amplified PCR products were then analyzed using MyImage (Seoulin Biotechnology).


### 2.3.3. Multiplex PCR

For the multiplex PCR amplification, 0.07 pmol of the primers Fb and R7; 0.14 pmol of the primers AYF and AYR; 0.7 pmol of the primer Aam F3; 1.7 pmol of the primers AC F4, ACJ R3, and Aap R2; 3.4 pmol of the primers 2F1, 2F3, AJ F1, AC R3, Aap F1, AA F3, and Aa R4; 1x PrimeSTAR® Max DNA Polymerase (Takara Bio Inc., Kusatsu, Japan); and 20 ng of genomic DNA extracted from eachArtemisia species were used. During the 30-cycle PCR process, predenaturation was conducted for 10 min at 95°C and denaturation for 10 s at 95°C. The annealing process was conducted for 5 s at 56.5°C and the extension process for 10 s at 72°C. A final reaction step was conducted for 7 min at 72°C. The amplified products were separated on 2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich). In order to amplify an internal standard for the evaluation of the PCR, the AYF/AYR primer set was used to amplify a 94 bp sequence. The amplified PCR products were then analyzed using MyImage (Seoulin Biotechnology).


## 2.3.1. Amplification of ITS

A PCR for the amplification of the ITS, including the 5.8S rRNA coding region, was conducted using a T-personal cycler (Biometra, Goettingen, Germany) according to the protocol by White et al. [21]. In brief, 1.2 pmol of ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) primers, 1 UTaq polymerase (ABgene, Epsom, UK), and 20 ng of genomic DNA extracted from each sample were used for the PCR amplification. During the 35-cycle PCR process, predenaturation was conducted for 5 min at 95°C and denaturation for 30 s at 95°C. The annealing process was conducted for 30 s at 52°C and the extension process for 1 min at 72°C. A final reaction step was conducted for 7 min at 72°C. The amplified products were separated on 1.2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich, St. Louis, MO, USA). The amplified PCR products were analyzed using MyImage (Seoulin Biotechnology, Seoul, Korea) and purified using a LaboPass™ Gel Kit (Cosmo Genetech, Seoul, Korea).


## 2.3.2. Amplification of DNA and SCAR Markers

In brief, 1.2 pmol of primers, 1 UTaq polymerase (ABgene), and 50 ng of genomic DNA extracted from eachArtemisia species were used for the PCR amplification. During the 23-cycle PCR process, predenaturation was conducted for 5 min at 95°C and denaturation for 30 s at 95°C. In general, the annealing process was conducted for 30 s at 53.5°C for the amplification of the DNA markers. However, to amplify the DNA markers forA. capillaris,A. japonica,A. apiacea,A. annua, andA. anomala, this process was conducted for 15–30 s at 54–58°C. The extension process was conducted for 20 s (except forA. apiacea, which had 30 s) at 72°C, and a final reaction step was conducted for 5 min at 72°C. To amplify an internal standard for the evaluation of the PCR conduct, a primer set (AYF/AYR) was used to amplify a 94 bp sequence. The amplified products were separated on 1.2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich). The amplified PCR products were then analyzed using MyImage (Seoulin Biotechnology).


## 2.3.3. Multiplex PCR

For the multiplex PCR amplification, 0.07 pmol of the primers Fb and R7; 0.14 pmol of the primers AYF and AYR; 0.7 pmol of the primer Aam F3; 1.7 pmol of the primers AC F4, ACJ R3, and Aap R2; 3.4 pmol of the primers 2F1, 2F3, AJ F1, AC R3, Aap F1, AA F3, and Aa R4; 1x PrimeSTAR® Max DNA Polymerase (Takara Bio Inc., Kusatsu, Japan); and 20 ng of genomic DNA extracted from eachArtemisia species were used. During the 30-cycle PCR process, predenaturation was conducted for 10 min at 95°C and denaturation for 10 s at 95°C. The annealing process was conducted for 5 s at 56.5°C and the extension process for 10 s at 72°C. A final reaction step was conducted for 7 min at 72°C. The amplified products were separated on 2% agarose gel and revealed by staining with ethidium bromide (Sigma-Aldrich). In order to amplify an internal standard for the evaluation of the PCR, the AYF/AYR primer set was used to amplify a 94 bp sequence. The amplified PCR products were then analyzed using MyImage (Seoulin Biotechnology).


## 2.4. Nucleotide Sequencing of the PCR Products

The nucleotide sequences of the PCR products were directly determined using the primers ITS1 and ITS4 by Macrogen (Seoul, Korea). In other cases, the PCR products resolved by agarose electrophoresis were cloned using a pGEM®-T Easy Vector System I (Promega, Madison, WI, USA). The nucleotide sequences of the subcloned PCR products were determined by Macrogen.


## 2.5. Alignment of the DNA Sequences and Construction of a Dendrogram

The DNA sequences were manually edited and aligned by ClustalW multiple sequence alignment in BioEdit v7.0.9 (http://www.mbio.ncsu.edu/BioEdit/bioedit.html). A dendrogram was constructed using the neighbor-joining method [22] in the MEGA6 program [23] with 1000 bootstrap iterations. Evolutionary distances were computed using the maximum composite likelihood method [24] in MEGA6.


## 3. Results

### 3.1. Determination and Analysis of ITS Sequences

The 726–731 bp nucleotide sequences of the ITS, including the 5.8S region, were determined in 65 samples of 12Artemisia species (Table 1). Parts of the ITS sequences of eachArtemisia species are presented in Figure 1 and were deposited in GenBank (accession numbers KT965653–KT965672). As shown in Figure 1, in the intraspecific samples of fiveArtemisia species (A. argyi,A. capillaris,A. iwayomogi,A. apiacea, andA. japonica), 4–9 bp differences in the ITS1 and ITS2 sequences were detected. In the case ofA. japonica (sample numbers 55, 58, and 59), there were 8 bp differences in the ITS2 region and a 1 bp difference in the ITS1 region. These differences resulted mainly from substitutions (mostly base transitions) and a deletion. InA. apiacea (sample numbers 45 and 46), two base deletions in ITS1 and two substitutions in ITS2 were detected in sample number 45.Figure 1
Multiple alignments of nucleotide sequences of the internal transcribed spacer (ITS) amongArtemisia species. The dots indicate consensus nucleotides and the dashes represent gaps. Numbers represent sample numbers (see Table 1). Bold arrows indicate the primers used to amplify DNA markers of theArtemisia species, and colored boxes represent nucleotide sequences as well as the positions of the ITS in the primers. Black boxes with an asterisk indicate variations in the nucleotides within species.To determine whether eachArtemisia species could be identified by interspecific ITS sequence differences, we constructed a dendrogram based on the ITS sequences. As outgroups, we used GenBank sequences ofAster yomena (accession number HQ154048.1) andChrysanthemum coronarium (accession number EF577292.1) in the family Asteraceae, in whichArtemisia is included (Figure 2). As shown in Figure 2, eachArtemisia species was classified into a separate group on the dendrogram. All of theA. japonica samples that exhibited excessive intraspecific ITS sequence variation were sorted into a group. Fortunately, theA. capillaris samples were separate from theA. japonica samples on the dendrogram. In addition, bothA. annua andA. apiacea, which are sources of Artemisia Annuae Herba, were classified into the same cluster on the dendrogram (Figure 2). Interestingly,A. argyi,A. princeps,A. montana,A. lavandulaefolia, andA. asiatica, which are sources of Artemisiae Argyi Folium, were classified into only one cluster.Figure 2
Dendrogram based on the internal transcribed spacer (ITS) sequences presented in Figure1. ITS sequences ofAster yomena (accession number HQ154048.1) andChrysanthemum coronarium (accession number EF577292.1) in GenBank were used as outgroups. The unit of evolutionary distance was the number of base substitutions per site; bootstrap values of over 50% are indicated on the branches of the dendrogram.


### 3.2. Discrimination ofA. capillaris from OtherArtemisia Species by Differences in ITS Sequences

Based on the results shown in Figure2, we could discriminateA. capillaris from otherArtemisia species, at least from the 11Artemisia species used in this study, by differences in the ITS sequences. It was difficult to discriminateA. capillaris fromA. japonica, which was close toA. capillaris on the dendrogram and exhibited significant variation in its ITS sequence. Most of the variation in the ITS sequences among the intraspecificA. japonica samples was found in the ITS2 region (Figure 1); therefore, we excluded the ITS2 region when designing primers to amplify specific DNA markers forA. japonica. As shown in Figures 1 and 3, we designed the primer set AC F4/ACJ R3 in order to amplify a 189 bp PCR product in the ITS1 region that only appeared inA. capillaris samples (Figures 3 and 4(a)). Subsequently, we designed the AJ F1/AC R3 primer set in order to amplify a 176 bp PCR product in ITS2 that only appeared inA. japonica samples (Figures 3 and 4(b)).Figure 3
Relative positions of the primers designed to amplify DNA markers ofArtemisia species on the internal transcribed spacer and the expected size of the polymerase chain reaction products.Figure 4
Polymerase chain reaction products of the primer sets AC F4/ACJ R3 (a) and AJ F1/AC R3 (b) from 12Artemisia species. Lane numbers are listed in Table 1. M: 100 bp ladder.
(a)
(b)Based on these results, we suggest that two primer sets (AJ F1/AC R3 and AC F4/ACJ R3) could be used to discriminateA. capillaris not only fromA. japonica but also from otherArtemisia species.


### 3.3. Discrimination ofArtemisia Species That Are Sources of Artemisiae Annuae Herba and Artemisiae Anomalae Herba by Differences in ITS Sequences

We developed DNA markers in order to detect contamination ofA. capillaris by otherArtemisia species. As shown in Figure 2,A. annua andA. apiacea, which are sources of Artemisiae Annuae Herba, were close together on the dendrogram in a similar manner asA. capillaris andA. japonica. Therefore, we attempted to find region(s) in ITS1 and ITS2 to discriminate bothA. annua andA. apiacea from otherArtemisia species. As shown in Figures 1 and 3, we designed the AA F3/Aa R4 primer set in order to amplify a 543 bp PCR product in bothA. annua andA. apiacea simultaneously as a common DNA marker. Subsequently, we designed primers to amplify a specific DNA marker to discriminateA. annua fromA. apiacea. Based on the differences found in the ITS1 and ITS2 sequences, we designed the Aap F1/Aap R2 primer set in order to amplify a 594 (in sample number 45, which had a 2 bp deletion) or 596 bp (in sample number 46) PCR product that only appeared inA. apiacea samples (Figures 1 and 3). Based on amplifications of the one or two PCR products expected on the gel (Figure 5(a)), we confirmed that the AA F3/Aa R4 and Aap F1/Aap R2 primer sets could discriminate not onlyA. annua fromA. apiacea but also these two species from otherArtemisia species. In the case ofA. anomala, we designed an Aam F3/Aa R4 primer set in order to amplify a 492 bp PCR product inA. anomala samples (Figures 1 and 3) and confirmed that the expected 492 bp single band of the PCR product only appeared inA. anomala samples (Figure 5(b)).Figure 5
Polymerase chain reaction products of the primer sets AA F3/Aa R4 and Aap F1/Aap R2 (a) and Aam F3/Aa R4 (b) from 12Artemisia species. Lane numbers are listed in Table 1. M: 100 bp ladder.
(a)
(b)


### 3.4. Detection of Contamination by OtherArtemisia Species Using Multiplex PCR

As shown in Figures1 and 2, differences in the ITS sequences could discriminate fiveArtemisia species—A. asiatica,A. montana,A. lavandulaefolia,A. argyi, andA. princeps—that are sources of Artemisiae Argyi Folium andA. iwayomogi that is a source of Artemisiae Iwayomogii Herba from the six otherArtemisia species. However, designing primers in order to amplify DNA markers for these species based on differences in the ITS sequences was difficult. Therefore, we tested the usability of the Fb/R7 and 2F1/2F3 primer sets in order to amplify SCAR markers that were developed in previous studies with sixArtemisia species [5, 7]. We confirmed that the Fb/R7 primer set amplified a 254 bp SCAR marker in samples of not onlyA. princeps andA. argyi but alsoA. asiatica,A. lavandulaefolia, andA. montana (data not shown). Furthermore, we confirmed that the 2F1/2F3 primer set amplified a 364 or 365 bp SCAR marker only inA. iwayomogi, and that this marker was not amplified in any other species, includingA. asiatica,A. montana,A. lavandulaefolia,A. annua,A. apiacea, orA. anomala (data not shown). Therefore, these two RAPD-based primer sets could detect contamination by theseArtemisia species in addition to the six otherArtemisia species. Using the multiplex PCR method, we tested the reliability of these two primer sets and those developed based on the ITS sequences to discriminateA. capillaris from otherArtemisia species and to detect contamination by otherArtemisia species. For the multiplex PCR process, we randomly selected one sample from eachArtemisia species listed in Table 1. As shown in Figure 6, these primer sets functioned reliably, not only to discriminateA. capillaris from otherArtemisia species, but also to simultaneously detect contamination by otherArtemisia species in a single PCR process.Figure 6
Multiplex polymerase chain reaction products using the primers shown in Figures1 and 3 from 12 randomly selectedArtemisia species. Genomic DNA from a randomly chosen sample of eachArtemisia species was used for PCR amplification. M: 100 bp ladder.Finally, by mixing genomic DNA isolated from differentArtemisia species at varying content ratios, we tested the reliability of this PCR method to detect contamination of otherArtemisia species, such asA. japonica,A. princeps, andA. iwayomogi, which are mostly found in Korea and are easily misused. As shown in Figure 7, the multiplex PCR detected twoArtemisia species that had been mixed at ratios of 9 : 1 and 19 : 1. Furthermore, the multiplex PCR detected a mixture of threeArtemisia species (A. capillaris withA. japonica andA. princeps orA. capillaris withA. japonica andA. iwayomogi) at ratios of 8 : 1 : 1 and 18 : 1 : 1 (Figure 7). Therefore, we suggest that the multiplex PCR method is an accurate tool to discriminateA. capillaris from otherArtemisia species and could be used to determine whetherA. capillaris samples have been mixed with otherArtemisia species.Figure 7
Multiplex polymerase chain reaction products by using two or three combined primer sets from mixed genomic DNA isolated from two or threeArtemisia species at different content ratios. Primer set AC F4/ACJ R3 amplified a 189 bp DNA marker to detectA. capillaris; AJ F1/AC R3 amplified a 176 bp DNA marker to detectA. japonica; Fb/R7 amplified a 254 bp DNA marker to detectA. princeps; 2F1/2F3 amplified a 365 bp DNA marker to detectA. iwayomogi. Lane 1:A. capillaris; Lane 2:A. capillaris andA. japonica (9 : 1); Lane 3:A. capillaris andA. japonica (19 : 1); Lane 4:A. capillaris andA. princeps (9 : 1); Lane 5:A. capillaris andA. princeps (19 : 1); Lane 6:A. capillaris andA. iwayomogi (9 : 1); Lane 7:A. capillaris andA. iwayomogi (19 : 1); Lane 8:A. capillaris,A. japonica, andA. princes (8 : 1 : 1); Lane 9:A. capillaris,A. japonica, andA. princeps (18 : 1 : 1); Lane 10:A. capillaris,A. japonica, andA. iwayomogi (8 : 1 : 1); Lane 11:A. capillaris,A. japonica, andA. iwayomogi (18 : 1 : 1); M: 100 bp ladder, yellow underline: 96 bp internal standard amplified by AYF/AYR primer set.


## 3.1. Determination and Analysis of ITS Sequences

The 726–731 bp nucleotide sequences of the ITS, including the 5.8S region, were determined in 65 samples of 12Artemisia species (Table 1). Parts of the ITS sequences of eachArtemisia species are presented in Figure 1 and were deposited in GenBank (accession numbers KT965653–KT965672). As shown in Figure 1, in the intraspecific samples of fiveArtemisia species (A. argyi,A. capillaris,A. iwayomogi,A. apiacea, andA. japonica), 4–9 bp differences in the ITS1 and ITS2 sequences were detected. In the case ofA. japonica (sample numbers 55, 58, and 59), there were 8 bp differences in the ITS2 region and a 1 bp difference in the ITS1 region. These differences resulted mainly from substitutions (mostly base transitions) and a deletion. InA. apiacea (sample numbers 45 and 46), two base deletions in ITS1 and two substitutions in ITS2 were detected in sample number 45.Figure 1
Multiple alignments of nucleotide sequences of the internal transcribed spacer (ITS) amongArtemisia species. The dots indicate consensus nucleotides and the dashes represent gaps. Numbers represent sample numbers (see Table 1). Bold arrows indicate the primers used to amplify DNA markers of theArtemisia species, and colored boxes represent nucleotide sequences as well as the positions of the ITS in the primers. Black boxes with an asterisk indicate variations in the nucleotides within species.To determine whether eachArtemisia species could be identified by interspecific ITS sequence differences, we constructed a dendrogram based on the ITS sequences. As outgroups, we used GenBank sequences ofAster yomena (accession number HQ154048.1) andChrysanthemum coronarium (accession number EF577292.1) in the family Asteraceae, in whichArtemisia is included (Figure 2). As shown in Figure 2, eachArtemisia species was classified into a separate group on the dendrogram. All of theA. japonica samples that exhibited excessive intraspecific ITS sequence variation were sorted into a group. Fortunately, theA. capillaris samples were separate from theA. japonica samples on the dendrogram. In addition, bothA. annua andA. apiacea, which are sources of Artemisia Annuae Herba, were classified into the same cluster on the dendrogram (Figure 2). Interestingly,A. argyi,A. princeps,A. montana,A. lavandulaefolia, andA. asiatica, which are sources of Artemisiae Argyi Folium, were classified into only one cluster.Figure 2
Dendrogram based on the internal transcribed spacer (ITS) sequences presented in Figure1. ITS sequences ofAster yomena (accession number HQ154048.1) andChrysanthemum coronarium (accession number EF577292.1) in GenBank were used as outgroups. The unit of evolutionary distance was the number of base substitutions per site; bootstrap values of over 50% are indicated on the branches of the dendrogram.


## 3.2. Discrimination ofA. capillaris from OtherArtemisia Species by Differences in ITS Sequences

Based on the results shown in Figure2, we could discriminateA. capillaris from otherArtemisia species, at least from the 11Artemisia species used in this study, by differences in the ITS sequences. It was difficult to discriminateA. capillaris fromA. japonica, which was close toA. capillaris on the dendrogram and exhibited significant variation in its ITS sequence. Most of the variation in the ITS sequences among the intraspecificA. japonica samples was found in the ITS2 region (Figure 1); therefore, we excluded the ITS2 region when designing primers to amplify specific DNA markers forA. japonica. As shown in Figures 1 and 3, we designed the primer set AC F4/ACJ R3 in order to amplify a 189 bp PCR product in the ITS1 region that only appeared inA. capillaris samples (Figures 3 and 4(a)). Subsequently, we designed the AJ F1/AC R3 primer set in order to amplify a 176 bp PCR product in ITS2 that only appeared inA. japonica samples (Figures 3 and 4(b)).Figure 3
Relative positions of the primers designed to amplify DNA markers ofArtemisia species on the internal transcribed spacer and the expected size of the polymerase chain reaction products.Figure 4
Polymerase chain reaction products of the primer sets AC F4/ACJ R3 (a) and AJ F1/AC R3 (b) from 12Artemisia species. Lane numbers are listed in Table 1. M: 100 bp ladder.
(a)
(b)Based on these results, we suggest that two primer sets (AJ F1/AC R3 and AC F4/ACJ R3) could be used to discriminateA. capillaris not only fromA. japonica but also from otherArtemisia species.


## 3.3. Discrimination ofArtemisia Species That Are Sources of Artemisiae Annuae Herba and Artemisiae Anomalae Herba by Differences in ITS Sequences

We developed DNA markers in order to detect contamination ofA. capillaris by otherArtemisia species. As shown in Figure 2,A. annua andA. apiacea, which are sources of Artemisiae Annuae Herba, were close together on the dendrogram in a similar manner asA. capillaris andA. japonica. Therefore, we attempted to find region(s) in ITS1 and ITS2 to discriminate bothA. annua andA. apiacea from otherArtemisia species. As shown in Figures 1 and 3, we designed the AA F3/Aa R4 primer set in order to amplify a 543 bp PCR product in bothA. annua andA. apiacea simultaneously as a common DNA marker. Subsequently, we designed primers to amplify a specific DNA marker to discriminateA. annua fromA. apiacea. Based on the differences found in the ITS1 and ITS2 sequences, we designed the Aap F1/Aap R2 primer set in order to amplify a 594 (in sample number 45, which had a 2 bp deletion) or 596 bp (in sample number 46) PCR product that only appeared inA. apiacea samples (Figures 1 and 3). Based on amplifications of the one or two PCR products expected on the gel (Figure 5(a)), we confirmed that the AA F3/Aa R4 and Aap F1/Aap R2 primer sets could discriminate not onlyA. annua fromA. apiacea but also these two species from otherArtemisia species. In the case ofA. anomala, we designed an Aam F3/Aa R4 primer set in order to amplify a 492 bp PCR product inA. anomala samples (Figures 1 and 3) and confirmed that the expected 492 bp single band of the PCR product only appeared inA. anomala samples (Figure 5(b)).Figure 5
Polymerase chain reaction products of the primer sets AA F3/Aa R4 and Aap F1/Aap R2 (a) and Aam F3/Aa R4 (b) from 12Artemisia species. Lane numbers are listed in Table 1. M: 100 bp ladder.
(a)
(b)


## 3.4. Detection of Contamination by OtherArtemisia Species Using Multiplex PCR

As shown in Figures1 and 2, differences in the ITS sequences could discriminate fiveArtemisia species—A. asiatica,A. montana,A. lavandulaefolia,A. argyi, andA. princeps—that are sources of Artemisiae Argyi Folium andA. iwayomogi that is a source of Artemisiae Iwayomogii Herba from the six otherArtemisia species. However, designing primers in order to amplify DNA markers for these species based on differences in the ITS sequences was difficult. Therefore, we tested the usability of the Fb/R7 and 2F1/2F3 primer sets in order to amplify SCAR markers that were developed in previous studies with sixArtemisia species [5, 7]. We confirmed that the Fb/R7 primer set amplified a 254 bp SCAR marker in samples of not onlyA. princeps andA. argyi but alsoA. asiatica,A. lavandulaefolia, andA. montana (data not shown). Furthermore, we confirmed that the 2F1/2F3 primer set amplified a 364 or 365 bp SCAR marker only inA. iwayomogi, and that this marker was not amplified in any other species, includingA. asiatica,A. montana,A. lavandulaefolia,A. annua,A. apiacea, orA. anomala (data not shown). Therefore, these two RAPD-based primer sets could detect contamination by theseArtemisia species in addition to the six otherArtemisia species. Using the multiplex PCR method, we tested the reliability of these two primer sets and those developed based on the ITS sequences to discriminateA. capillaris from otherArtemisia species and to detect contamination by otherArtemisia species. For the multiplex PCR process, we randomly selected one sample from eachArtemisia species listed in Table 1. As shown in Figure 6, these primer sets functioned reliably, not only to discriminateA. capillaris from otherArtemisia species, but also to simultaneously detect contamination by otherArtemisia species in a single PCR process.Figure 6
Multiplex polymerase chain reaction products using the primers shown in Figures1 and 3 from 12 randomly selectedArtemisia species. Genomic DNA from a randomly chosen sample of eachArtemisia species was used for PCR amplification. M: 100 bp ladder.Finally, by mixing genomic DNA isolated from differentArtemisia species at varying content ratios, we tested the reliability of this PCR method to detect contamination of otherArtemisia species, such asA. japonica,A. princeps, andA. iwayomogi, which are mostly found in Korea and are easily misused. As shown in Figure 7, the multiplex PCR detected twoArtemisia species that had been mixed at ratios of 9 : 1 and 19 : 1. Furthermore, the multiplex PCR detected a mixture of threeArtemisia species (A. capillaris withA. japonica andA. princeps orA. capillaris withA. japonica andA. iwayomogi) at ratios of 8 : 1 : 1 and 18 : 1 : 1 (Figure 7). Therefore, we suggest that the multiplex PCR method is an accurate tool to discriminateA. capillaris from otherArtemisia species and could be used to determine whetherA. capillaris samples have been mixed with otherArtemisia species.Figure 7
Multiplex polymerase chain reaction products by using two or three combined primer sets from mixed genomic DNA isolated from two or threeArtemisia species at different content ratios. Primer set AC F4/ACJ R3 amplified a 189 bp DNA marker to detectA. capillaris; AJ F1/AC R3 amplified a 176 bp DNA marker to detectA. japonica; Fb/R7 amplified a 254 bp DNA marker to detectA. princeps; 2F1/2F3 amplified a 365 bp DNA marker to detectA. iwayomogi. Lane 1:A. capillaris; Lane 2:A. capillaris andA. japonica (9 : 1); Lane 3:A. capillaris andA. japonica (19 : 1); Lane 4:A. capillaris andA. princeps (9 : 1); Lane 5:A. capillaris andA. princeps (19 : 1); Lane 6:A. capillaris andA. iwayomogi (9 : 1); Lane 7:A. capillaris andA. iwayomogi (19 : 1); Lane 8:A. capillaris,A. japonica, andA. princes (8 : 1 : 1); Lane 9:A. capillaris,A. japonica, andA. princeps (18 : 1 : 1); Lane 10:A. capillaris,A. japonica, andA. iwayomogi (8 : 1 : 1); Lane 11:A. capillaris,A. japonica, andA. iwayomogi (18 : 1 : 1); M: 100 bp ladder, yellow underline: 96 bp internal standard amplified by AYF/AYR primer set.


## 4. Discussion

Medicinal plants have long been used to treat disease in traditional and modern medicine [1]. However, because of the substitution and adulteration of medicinal plants with closely related species, the value of the original drug decreases and in some cases can make it lethal when substituted or contaminated with toxic adulterant plant(s) [3]. Therefore, the authentication of medicinal plants is crucial. As mentioned previously,A. capillaris, which is a source of Artemisiae Capillaris Herba, should be discriminated from not onlyA. japonica,A. argyi, andA. princeps but also otherArtemisia species that grow and/or are cultivated in Korea and China and could contaminate the products ofA. capillaris.Artemisia species, includingA. capillaris, are a valuable source of new drugs and essential oils, and their unique chemical compositions and pharmacological activity are species-specific [1, 2, 5]. In this context, we developed a method to discriminateA. capillaris from otherArtemisia species and to detect contamination amongArtemisia species.The DNA barcode is a powerful tool for identifying and discriminating between species of animal, plant, and fungus. The sequence at the 5′ end of cytochrome c oxidase subunit 1 (CO1) in the mitochondrial genome is used for animal taxonomic classification [25, 26]; however, plants cannot currently be identified by the sequence of a single locus [3]. Therefore, the Consortium for the Barcode of Life (CBOL) Plant Working Group proposed a combination of sequences ofmatK in the nuclear genome andrbcL in the chloroplast genome to identify plants [3]. However, the discriminatory power of the combinedmatK andrblL loci is low, particularly when discriminating between closely related species, such as 36 species in the genusDendrobium [27]. Instead, by using a singlematK sequence, medicinal plants in the subfamily Rauvolfioideae and genusRheum have been successfully discriminated from each other [28, 29]. Despite the relatively low level of variation found inrbcL sequences in 48 plant genera includingAmaranthus,Angelica, andIlex, their combination withtrnH-psbA intergenic spacer sequences increased the identification and discrimination success rate from 79% to 88% [30]. Therefore, to identify or discriminate between specific medicinal plants and closely related species, other single loci, besidesCO1, or a combination of loci, besidesmatK andrbcL, have been used. For example, variousDendrobium Sw. species have been discriminated between them using a single sequence of thetrnH-psbA intergenic spacer [31]. In addition, thetrnL-trnF intergenic spacer sequence clearly discriminatedCardiocrinum giganteum fromC. giganteum var. yunnanense andC. cordatum [32].Of the various DNA barcode loci used, the ITS is one of the most useful. Multiple copies of the ITS are tandemly located at one or more chromosomal loci, and there are hundreds or thousands of ITS repeats in the nuclear genome. Furthermore, the ITS, including ITS1, 5.8S rRNA, and ITS2, is relatively small and ranges from 400 bp to under 1000 bp long [33]. Because of the presence of high copy numbers of the ITS and its small size, the ITS is easily amplified by PCR [34]. The level of variation among interspecific ITS sequences is high, so they can be used for the identification of plants at the specific, generic, and even family levels [35]. In contrast, levels of variation within intraspecific ITS sequences are often very low [34]. Concerted evolution should homogenize the sequences of ITS repeats that exist in a species by high-frequency unequal crossing over or gene conversion [36, 37]. The ITS2 sequence in particular has been used to identify medicinal plants that belong to the generaSwartzia andArtemisia in the family Fabaceae [13, 14]. In addition, ITS2 sequences, combined withrbcL sequences, have been used for detecting the contamination and substitution of products from 42 medicinal plants, includingAchillea racemose andUrtica dioica, in Canada and the USA [38].As shown in Figures1 and 2, discriminatingA. capillaris fromA. japonica and 10 otherArtemisia species was based upon differences in ITS sequences among theArtemisia species. Using the RAPD method with nonspecific primers, we were unable to discriminateA. capillaris fromA. japonica in a previous study [5, 7]. Here, we were able to discriminateA. capillaris fromA. japonica because of differences in nucleotide sequences, particularly in the ITS2 region (Figure 1). Basing discrimination on differences in ITS sequences was conducted cautiously, because of the considerable sequence variation found in the ITS sequences, particularly among intraspecificA. japonica samples. We also observed this variation in theA. japonica ITS sequences deposited in GenBank (accession numbers AM398882, AY548200, GU724289, JF326554, JX051713, and KC493078). Therefore, we confirmed the discriminatory power of the ITS sequences by using theA. capillaris andA. japonica ITS sequences deposited in GenBank. The depositedA. japonica sequences, together with theA. japonica sequences determined in this study (sample numbers 55–60), were clearly discriminated from both the deposited (accession numbers AY548201 and KC493083) and determined (sample numbers 25–32)A. capillaris sequences (data not shown).Therefore, differences in ITS sequences can be used to discriminate amongArtemisia species, despite the large variations observed in the ITS sequences of specificArtemisia species. Lee et al. [39] compared ITS sequences amongArtemisia species that grow naturally in Korea, including two varieties and one subspecies ofA. japonica. They estimated the pairwise divergence value as 0.004 between the varieties and subspecies based on the Kiura-2 parameter. Because we could not find any sequence information in their article or GenBank, we were unable to determine how many nucleotide variations exist between the varieties and subspecies ofA. japonica. However, based on the results of their study, we suggest that the intraspecific ITS sequence variation detected inA. japonica could result from the different varieties and/or subspecies ofA. japonica used for the determination of the ITS sequences.For the discrimination ofA. capillaris fromA. japonica, which were closer to each other than to any otherArtemisia species on the dendrogram (Figure 2), the primer sets AC F4/ACJ R3 (that amplified a 189 bp DNA marker inA. capillaris) and AJ F1/AC R3 (that amplified a 176 bp DNA marker inA. japonica) were designed (Figures 1 and 3). Despite the fact that there was not a remarkable difference in the sizes of the DNA markers forA. capillaris andA. japonica, they were clearly separated on 2% agarose gel after 40 min of gel running (Figure 6).The method of amplifying double DNA markers of specific species was used to discriminateA. annua fromA. apiacea, which were close to each other on the dendrogram (Figure 2). A 543 bp DNA marker was only amplified inA. annua using the AA F3/Aa R4 primer set, and both the 543 and 594 bp (or 596 bp, depending on the presence of a base deletion) DNA markers were amplified inA. apiacea using the AA F3/Aa R4 and Aap F1/Aap R2 primer sets, respectively (Figures 5(a) and 5(b)). For the discrimination of the fiveArtemisia species that are sources of Artemisiae Argyi Folium, we first determined whether the nonspecific UBC primer 329 (5′-GCGAACCTCC-3′), which amplified a unique 850 bp PCR product only inA. argyi andA. princeps in a previous study [7], could amplify the same PCR product in three additionalArtemisia species (A. asiatica,A. montana, andA. lavandulaefolia). Using samples from the 12 species, we confirmed that the same PCR products were amplified in these threeArtemisia species (data not shown). We then confirmed that the Fb/R7 primer set, which was designed to amplify a 254 bp SCAR marker based on the sequence of an 850 bp PCR product [7], amplified the same-sized DNA marker in the three additionalArtemisia species (data not shown). For the discrimination ofA. iwayomogi, we tested whether the nonspecific UBC primer 391 (5′-GCGAACCTCG-3′), which amplified four kinds of PCR products that ranged in size from 707 to 719 bp inA. iwayomogi in a previous study [5], could amplify the same PCR products in six additionalArtemisia species (A. asiatica,A. montana,A. lavandulaefolia,A. apiacea,A. annua, andA. anomala). We confirmed that the UBC primer 391 amplified PCR products only inA. iwayomogi. In addition, we confirmed that the 2F1/2F3 primer set, which was designed to amplify a 365 bp SCAR marker based on the sequences of four PCR products [5], amplified the same-sized DNA marker only inA. iwayomogi (data not shown). Based on these results, we were convinced that the Fb/R7 and 2F1/2F3 primer sets could discriminateA. capillaris not only from the fiveArtemisia species that are sources of Artemisiae Argyi Folium but also fromA. iwayomogi.Using primer sets based on the ITS sequences and RAPD results to discriminate among theArtemisia species, we evaluated the multiplex PCR method to discriminateA. capillaris and to detect contamination ofA. capillaris by randomly selecting each sample ofArtemisia species (Figure 6) and mixed samples ofA. capillaris withA. japonica,A. princeps, andA. iwayomogi (Figure 7). Therefore, we suggest that the multiplex PCR method is an accurate tool to discriminateA. capillaris from otherArtemisia species and could be used to determine whetherA. capillaris samples have been mixed with samples from otherArtemisia species, at least those tested in this study.


## 5. Conclusion

To differentiate amongA. capillaris plants that produce Artemisiae Capillaris Herba and 11 otherArtemisia species, 726–731 bp ITS nucleotide sequences in 65 samples were determined and analyzed. Based on differences found in partial ITS nucleotide sequences between the species, we designed the primer sets AC F4/ACJ R3 to amplify a 189 bp PCR product and AJ F1/AC R3 to amplify a 176 bp PCR product inA. capillaris andA. japonica, respectively. To detect traces of otherArtemisia species inA. capillaris, we designed the primer set AA F3/Aa R4 to amplify a 543 bp product inA. annua, the primer set Aap F1/Aap R2 to amplify a 594–596 bp product inA. apiacea, and the primer set Aam F3/Aa R4 to amplify a 492 bp product inA. anomala. In addition, we confirmed that the primer sets Fb/R7 and 2F1/2F3, which had been developed in a previous study based on RAPD, could be used to amplify 254 bp products inA. princeps,A. argyi,A. asiatica,A. lavandulaefolia, andA. montana, which are sources of Artemisiae Argyi Folium, and to amplify 364 or 365 bp products inA. iwayomogi. Therefore, we demonstrate that the discrimination ofA. capillaris from and the detection of contamination by otherArtemisia species can be reliably performed by multiplex PCR using these primers.



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*Source: 7043436-2016-05-30.xml*