Yeongnam Agricultural Research Institute, NICS, RDA, Milyang, 627-130, Korea , www.nyaes.go.kr Email jung100@rda.go.kr
Recently diploid (2n=20) wild type Perilla species was reported from Japan. We collected several wild type Perilla in Jeju island, Korea. Two collections, Jeju-3 and Jeju-17, could be classified as P. citriodora and P. hirtella, respectively. Their bract color and type of serration at leaf base are agreed with the classification. Collections and their corresponding species shared specific RAPD markers which distinguished them from other species.
Key Words
Perilla, frutescens, citriodora, hirtella
Perilla (Perilla frutescens Brit.) is widely cultivated as an oil seed and vegetable crop in Korea and other Asian countries. The species includes two varieties that are differentiated on the basis of their morphology and dual uses. Perilla frutescens var. frutescens is used as an oil crop (Ren in chinese, Deulggae in Korean and Egoma in Japanese). The other is P. frutescens var. crispa, a Chinese medicine or vegetable crop (Zisu in chinese, Cha-jo-ki in Korean and Shiso in Japanese). Since P. frutescens has been extensively cultivated and used in East Asia, the origin of Perilla crops has generally been considered to be East Asia (Makino 1961, Li 1969, Nitta 2001), although the wild ancestor of P. frutescens has not yet been identified. These two crops have the same chromosome number, 2n = 40 (Yamane 1950, Honda et al. 1994), and are cross-fertile by artificial pollination.
In this study, we report two new wild type Perilla species in Korea and characterized their morphological and molecular biological characteristics.
Twenty wild type Perilla germplasm were collected from Jeju island, Korea in 2002. Their seed were planted in a green house on June 1 in 2003 at National Yeongnam Agricultural Experiment Station, RDA, Korea. DNA was extracted from fresh leaf of each collection and used for RAPD analysis. At flowering time, morphological characteristics were observed. Root tips were used to observe chromosomes and pretreated with 8-hydroxy quinoline for three hours following fixing overnight. Specimens were softened for 30 seconds in 60 centi-degree of 1N HCl and stained with 0.1% of aceto-carmin. Specimens were observed under microscope (Zeiss Axioplan) and photographed by the Sony 3CCD color video camera (CCD-IRIS) aided with software KS400 (Ver. 2.0, Kontron Electronik).
Among 20 wild type collections, only two collections Jeju-3 and Jeju-17 were identified as P. hirtella and P. citriodora, respectively. Chromosome number of Jeju-3 and Jeju-17 were 20 but were 40 in other collections of other Perilla species (Figure 1). Though the karyotyping was impossible because of small chromosome of Perilla, the size of chromosomes among different species appeared to be similarWe think Perilla as allo-tetraploid because many characteristics follow Mendel’s laws, no quadrivalent pairing has been reported yet. Phenotype was clearly distinguished in different species and the characteristics agreed with previous reports (Nitta 2001). Jeju-17 shows a white bract colour that is a unique characteristics of P. citriodora(Table 1) Distinct serration is an inherence characteristic of P. hirtella which is shown in Jeju-3 but is absent in Jeju-17 and P. citriodora . Jeju-3 and Jeju-17 showed unique RAPD markers which were same as in P. hirtella and P. citriodora, respectively (Figure 2).
Table 1. Taxonomic characteristics of three Perilla species and two wild type collections.
Character |
P. hirtella |
P. citriodora |
P. frutescens |
Collected 3 |
Collected17 |
Serration at leaf base |
distinct |
indistinct |
indistinct |
distinct |
indistinct |
Bract color |
green |
white |
green |
green |
white |
Chromosome number (2n) |
20 |
20 |
40 |
20 |
20 |
Figure 1. Aceto-carmin stained metaphase chromosome of Perilla species. A; Jeju-3, B; Jeju-17, C; P. frutescens.
Figure 2. RAPD pattern of two wild type Jeju-3(J3) and Jeju-17(J17) and three diploid species P. citriodora (PC), P. setoyensis (PS) and P. hirtella (PH). Jeju-3 and Jeju-17 (CPAAII) showed same markers with P. hirtella and P. citriodora, respectively.
With this result it is suggested that the Perilla frutescens is not diploid but tetrapoloid. Diploid species P.citriodora and P.hirtella are possibly the ancestor of Perilla species.
Nitta M (2001). Origin of Perilla crops and their weedy type. PhD, Kyoto University, Kyoto.
Makino T (1961). In ‘Makino new illustrated flora of Japan’. (Ed. T. Makino) Hokuryukan Publ., Tokyo
Li HL (1969). The vegetables of ancient China. Econ. Bot. 23, 235-260.
Yamane Y (1950). Cytogenetic studies in Perilla and coleus. I. Chromosome Numbers. Jpn. J. Genet. 25, 220.
Honda G, Yuba A, Kojima T, and Tabata M (1994). Chemotaxonomic and cytogenetic studies on Perilla frutescens var. citriodora (“Lemon Egoma”). Natural Medicine 48, 185-190.