Caffeine: The Allelochemical Responsible for the Plant Growth Inhibitory Activity of Vietnamese Tea (Camellia sinensis L. Kuntze)

Agronomy

Yoshiharu FUJII¹  VanThi Thanh PHAM¹  KwameSarpong APPIAH¹  Yosei OIKAWA¹  Tamer ISMAIL²  Maryia MISHYNA³ 

[1] Department of Biological Production Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8504, Japan;Department of Pesticide Chemistry and Toxicology, Agriculture Faculty, Kafrelsheikh University, 33516 Kafrelsheikh, Egypt;School of Food Science and Bioengineering, Zhejiang Gongshang University, Hangzhou 310018, China;

关键词: allelopathy;    caffeine;    Camellia sinensis;    specific activity tea;    total activity;   

DOI  :  10.3390/agronomy9070396

来源: DOAJ

【 摘 要 】

The present study aimed to examine the phytotoxic potential of seven Vietnamese tea samples based on the specific and total activity of caffeine and tea extracts on test plants. The sandwich method results indicated that the inhibitory effect of tea samples on the radicle and hypocotyl growth of lettuce seedlings was dependent on the concentration and type of tea samples, and also the presence of agar soluble allelochemicals. Among the seven tea samples, the leachates from Vinatea-green tea showed the highest inhibition on the radicle growth of lettuce seedlings with 50% suppression at 0.12 mg dry leaves/mL of agar. Caffeine concentration in tea samples analyzed by high-performance liquid chromatography (HPLC) varied from 20.7 to 38.2 µg/mL of dry leaves. The specific activity (EC₅₀ value) of pure caffeine was 75 µg/mL, and the highest total activity of caffeine estimated in Vinatea-green tea was 0.51 [no unit]. Caffeine from green and oolong tea may be considered as one of the contributors to the inhibitory activity of the crude extract. Moreover, the phytotoxicity of pure caffeine and aqueous tea extracts was highly selective on the growth of different plant species. The concentration of caffeine detected from tea farm soil ranged from 0.137 to 0.145 µg/g soil. The results indicated that caffeine might be considered as a promising allelochemical from Vietnamese tea and can be a good candidate for weed management.

【 授权许可】

Unknown