GENETIC DIVERSITY OF ZANTHOXYLUM AVICENAE (Lam.) DC. BASED ON
INTERNAL TRANSCRIBED SPACER SEQUENCES OF NUCLEAR RIBOSOMAL
DNA
Phung Thanh Huong
1
, Pham Viet Cuong
1
, Phan Le Binh Mai
1
, Tran Van On
1
, Ha Thi Thu
2,
Khuat Huu Trung
3
1
Hanoi University of Pharmacy
13 Le Thanh Tong street, Hoankiem District, Hanoi, Viet Nam
2
Institute of Biotechnology – Vietnam Academy of Science and Technology
18 Hoang Quoc Viet street, Caugiay District, Hanoi, Viet Nam.
3
Agricultural Genetics Institute
Km 2, Pham Van Dong street, Tu liem, Hanoi, Vietnam.
Zanthoxylum avicennae (Lam.) DC. is a berberine containing species of the Rutaceae family
which distributes widely in Vietnam. In this study, 10 accessions of Zanthoxylum avicennae
(ZA) were collected from various regions of Vietnam for genetic diversity evaluation. The
internal transcribed spacer (ITS) of nuclear ribosomal DNA of the accessions were amplified
using the universal primers (ITS4/ ITS5). The PCR products were then cloned and sequenced.
Alignment analysis among the 10 sequences showed high similarity scores from 99.0 to 99.9%
which revealed a low level of diversity of ITS sequences among the Zanthoxylum avicennae
individuals in Vietnam. However, a phylogeny tree was established using ClustalX 2.0 on the
basis of the obtained sequences and divided the 10 accessions into 3 groups. Such genetic results
if are combined with phenotype comparisons would be helpful for valuable gene selection and
preservation.
Key words: genetic diversity, Zanthoxylum avicenae, ITS sequence, rDNA
Introduction
Zanthoxylum avicennae (Lam.) DC. is a species of the Rutaceae family which has been used for
years for treatment of itching, infections…Recently, it has been proved to have cytotoxic effects
on some cancer cell lines [4]. One of the most important active substances of Zanthoxylum
avicennae is berberine, a well-known substance with various pharmacological effects, especially
the anti-cancer activity. Therefore, Zanthoxylum avicennae has become a subject in a project for
gene preservation of berberine containing plants in Vietnam. In order to preserve gene sources,
it’s essential to evaluate the genetic diversity of the subjects.
The internal transcribed spacer (ITS) region of 18S-26S nuclear ribosomal DNA (including
ITS1, 5.8S and ITS2) has been popularly used in plant systematic to reconstruct phylogenetic
relationships at different taxonomic levels [1], [2]. The ITS region is claimed to be useful for
low-level phylogenetic analysis, such as infra-generic level, due to its relatively fast rate of
evolution. On the other hand, ITS is one of the most extensively used molecular markers for
studies of genetic diversity [5], [6].
This paper aims at evaluating genetic diversity of Zanthoxylum avicennae in Vietnam, using the
internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA.