Date Published: May 28, 2019
Publisher: Public Library of Science
Author(s): Takahiro Tsusaka, Bunsho Makino, Ryo Ohsawa, Hiroshi Ezura, Branislav T. Šiler.
Rhizomes of Atractylodes lancea are used in traditional Japanese medicine (Kampo) and Chinese medicine to treat numerous diseases and disorders because they contain many pharmacologically active compounds. The major active compounds in A. lancea are essential oil compounds such as β-eudesmol, hinesol, atractylon, and atractylodin. The contents of the compounds in A. lancea exhibit high variability depending on their habitat. We cultivated clonal lines of A. lancea in different years (2016, 2017) and different locations (Hokkaido, Ibaraki) to investigate the influence of genetic and environmental factors on the contents of major compounds, namely, β-eudesmol, hinesol, atractylon, and atractylodin. Broad sense heritability of β-eudesmol, hinesol, atractylon, and atractylodin contents were 0.84, 0.77, 0.86, and 0.87, respectively. The effects of interannual variability on the contents of the compounds were lower than those of genotype. In addition, the cultivated environmental factors were assessed by different locations, and the correlations between Hokkaido and Ibaraki grown plants based on β-eudesmol, hinesol, atractylon, and atractylodin contents were 0.94, 0.94, 1.00, and 0.83, respectively. The results suggest that the contents of β-eudesmol, hinesol, atractylon, and atractylodin in A. lancea are largely influenced by genetic factors, and clonal propagation could be an effective strategy for obtaining populations with high contents of essential oil compounds. Furthermore, the contents of β-eudesmol, hinesol, atractylon, and atractylodin in A. lancea exhibited few correlations with rhizome yields. A. lancea cultivars with not only high contents of essential oil compounds but also high rhizome yield could be developed through selective breeding.
Atractylodes lancea De Candolle (Compositae) is a medicinal plant that is distributed in East Asia, mainly in central China . Dried rhizomes of A. lancea are prescribed in Japanese and Chinese herbal medicines as the crude drugs [2, 3]. In Japan, the crude drug is called “So-Jutsu,” whereas in China, it is called “Chang-zhu” . The rhizomes of A. lancea have mainly been used for digestive disorders and body fluid imbalance [5, 6]. Major active ingredients in A. lancea were essential oil compounds, namely, sesquiterpenoids (β-eudesmol, hinesol, atractylon) and polyacetylene (atractylodin) . The sesquiterpenoid compounds have been reported to have anti-ulcer activity, while atractylodin has been reported to ameliorate the delayed gastric emptying [8, 9]. Based on pharmacological studies, such compounds are considered important bioactive ingredients in A. lancea . However, the drugs distributed in the market have hugely varied in contents of the major essential oil compounds, posing a challenge for the cultivation of A. lancea with constant quality . Therefore, it is critical to investigate the factors influencing the variation in the contents of essential oil compounds in A. lancea to keep pharmacological activities constant in many traditional prescriptions containing the crude drug .
In the present study, broad sense heritability for β-eudesmol, hinesol, atractylon, and atractylodin contents in A. lancea was high (Table 1), suggesting that the contents of the essential oil compounds in A. lancea are highly influenced by genetic factors. In addition, correlations between each compound contents and rhizome yield were low (Fig 2), indicating that A. lancea strains, which have high contents of essential oil compounds could be selectively bred irrespective of rhizome yields. Therefore, cultivars of A. lancea with not only high contents of essential oil compounds but also high yields could be developed through selective breeding.