TITLE:
Changes in Secondary Metabolites and Free Amino Acid Content in Tomato with Lamiaceae Herbs Companion Planting
AUTHORS:
Hasib Ahmad, Manami Kobayashi, Yoh-ichi Matsubara
KEYWORDS:
Basil, Growth Promotion, Hyssop, Peppermint, Root Exudate
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.12,
December
7,
2020
ABSTRACT: The present experiment was conducted to evaluate the
influence of Lamiaceae herbs companion planting on growth and secondary
metabolites changes in tomato plants. Furthermore, the free amino acid changes
in tomato due to companion planting were also evaluated using tomato-basil companionship as a model.
Four-week-old seedlings of tomato were grown in a pot containing autoclaved
commercial soil with basil, peppermint and hyssop as a companion plant
separately in different density. Four weeks after companion planting, tomato
plants under 1:1 companionship with the herbs showed significant increase in
dry weights of shoots compared to control. Higher density of the herbs on the
other hand expressed a growth suppression on tomato possibly due to nutrient
competition. By the LC-MS analysis, shikimic acid and apigenin were identified
as the major secondary compounds found in tomato plants and 1:1 companionship
with basil seemed to have a positive influence on their content in tomato
shoots. On the other hand, in case of peppermint and hyssop, the increase was
observed in all parts of tomato plants. In addition, promotion in several free
amino acid contents was also observed in tomato plants with basil companion planting compared to
control. Thus, tomato plants grown with herb companion planting in 1:1 ratio
seems to have a positive impact on growth of tomato. This positive influence
might be related to the increase in some secondary metabolites and changes in
the free amino acids observed in this study.