Chemical Constituents and Effective Growth Promoting Compounds in Matthiola incana Volatiles

PurposeTo explore the chemical constituents and identify the growth promoting compounds in the hoary stock (Matthiola incana) volatiles, finally to provide choice for developing natural growth regulators.

MethodThe volatile organic compounds (VOCs) of hoary stock aboveground part were analyzed by the air-purge method in normal pressure and temperature and gas chromatography-mass spectrometry, and the growth promoting activity of the compounds were tested with lettuce seeds.

ResultsThere were 37 compounds accounting for over 0.05% of the relative contents in hoary stock VOCs. They included 18 esters, eight terpenoids, three alcohols, three alkanes, two ketones, two phenols and one aldehyde. Among the 37 volatile compounds in hoary stock, 83.33% and 94.44% could promote stem growth and fresh weight of lettuce seedlings, while 27.78% and 44.44% promoted seed germination and root growth, respectively. Diethyl malonate, eugenol and anisole had significantly higher promoting effects on the lettuce seed germination than other chemical components (P<0.05), whose average response index (RI) were 0.30, 0.20 and 0.16, respectively. Eugenol and anisole had the best effects on the lettuce seedling stem growth, root growth and fresh weight (P<0.05), and the average RI were 0.79 and 0.76, 0.74 and 0.80, 0.56 and 0.56, respectively. In all, eugenol and anisole showed the most significant promoting effects on seed germination, stem and root growth, fresh weight (P<0.05), with synthetic effect values over 0.50.

ConclusionAllelopathic effects of hoary stock VOCs are closely related to the action site on the recipient plant and its mass concentration. The stem growth and fresh weight of the recipient plant are the sensitive indexes of the allelopathic action. The promoting effect of the compounds have a mass concentration effect, which display promoting effect at low mass concentration and inhibiting effect at high mass concentration. Eugenol and anisole have the strongest synthetic effect, which can be developed and utilized as natural growth regulators.