Impact of Edaphic and Climatic Factors on Thymus pulegioides Essential Oil Composition and Potential Prevalence of Chemotypes

Abstract

Intraspecific chemical polymorphism is characteristic of essential oil bearing Thymus pulegioides (Lamiaceae). Soil chemical composition and climatic conditions can influence not only quantitative and qualitative composition of essential oils, but also on prevalence of different chemotypes in space. The purpose of study was to determine the impact of edaphic and climatic factors on T. pulegioides essential oil composition and potential chemotypes prevalence. It were investigated 131 habitats of T. pulegioides in all ten climatic sub-districts of Lithuania. Essential oils were isolated by hydrodistillation and analysed by GC-FID and GC-MS. The content of humus was estimated by oxidation method, the content of mobile potassium (K2O) and mobile phosphorus (P2O5)—flame photometry using 0.2 M HCl solution, the soil pH—electrometrically and 15 elements of soil—by energy-dispersive X-ray fluorescence. The meteorological data (temperature, rainfall, photosynthetically active solar radiation and sunshine duration) were obtained from the meteorological bulletins. Results showed that humus in soil positively, manganese and cobalt—negatively influenced on the essential oil accumulation in T. pulegioides. Carvacrol was the most common compound in the essential oil of T. pulegioides; higher amounts of sulphur and mobile phosphorus, lower amounts of sodium in soil, higher rainfall in blooming period are favourable for this compound and for potential prevalence of carvacrol chemotype. Geraniol was frequent in the eastern and the central part of Lithuania, where the temperature in vegetation season is higher, and in soils characterised by higher and lower amounts of sodium and chlorine, respectively. Thymol, linalool and α-terpinyl acetate were rare. Edaphic and climatic conditions can differently influence on essential oil yield and chemical composition of species as well as on potential prevalence of different chemotypes of same species in space.

Geographic distribution of terpenoid chemotypes in Tanacetum vulgare mediates tansy aphid occurrence but not abundance

“…Perhaps the different soil types occurring in different sites, could partly explain the patterns of monoterpenoid chemotype classes, as previous studies have found that e.g. soil properties influenced essential oil composition in Thymus pulegioides (Vaičiulytė et al 2017, 2022). As our study only assessed soil type at the site level, variation in soil type and relationships with individual plants within sites could not be captured, and hence small‐scale variation in soil type as driver of local chemical variation warrants future study.…”

The essential oil composition of Picea sitchensis growing in the Oregon Coast Range

“…Total monoterpene concentration was shown to negatively influence browsing of P. sitchensis by red deer (Cervus elaphus) [35]. Genetic, edaphic, climatic, and geographic factors are often cited as affecting the essential oil profiles [36,37]. Latitudinal differences, including climatic differences, may be responsible for the lower monoterpene hydrocarbon concentrations and higher oxygenated monoterpenoid concentrations in the Oregon samples compared to the British Columbia samples.…”

Spatial Variation in Yield, Chemical Composition, and Phytotoxic Activity ofCistus ladaniferEssential Oils

“…However, another study conducted by Robles and Garzino (2000) [30] on Cistus monspeliensis showed, conversely, that plants grown on calcareous soils presented higher oil yields than those on siliceous soils. These variations detected in essential oil yields have often been linked to the influence of specific edaphoclimatic variables [31,32] …”

“…These variations detected in essential oil yields have often been linked to the influence of specific edaphoclimatic variables. [31,32] In contrast to the strong effect observed of edaphic factors on yield, microclimatic conditions do not seem to play a consistent role in explaining variations on yield, see data shown in Table S1. Therefore, these results indicate that the EO yielded can be significantly influenced by specific edaphic variables.…”