Effect of weather conditions on the morphology, production and chemical composition of two cultivated medicinal and aromatic species.

摘要

Two medicinal plant species (Achillea collina Becker and Hyssopus officinalis L.) normally occurring and frequently cultivated in our Central European region, were grown in controlled environment simulating cold and hot weather conditions. A cold environment (slowly increasing temperatures from 12.5/7.5 degrees C to 27.0/14.0 degrees C and 5700 lux illumination) prolonged the appearance of the first inflorescences by 9 weeks in both species. In yarrow, cold treatment resulted in elevated plant height (approximately by 50 %) and by up to 35 % larger leaves. In addition, plants produced more biomass (0.117 kg plant-1) compared to the hot treatment. The accumulation of essential oil, the proazulene ratio and the total phenol content of the herb have only been moderately effected by the different climatic conditions. In case of hyssop, however, the generative features like number and length of inflorescences were significantly increased by 180 and 108 %, respectively, in the hot chamber. Biomass and accumulation of essential oil were also favored by hot treatment. The content of 1.22 ml 100 g oil-1 exceeded the mean value of plants grown in the cold chambers by almost 150 %. The composition of the oil showed characteristic quantitative changes due to weather conditions. It is concluded that, while in cultivation of yarrow the effect of the year may considerably affect yield, in stands of hyssop it is more important for the quality.