Genetic and Metabolite Diversity of Sardinian Populations of Helichrysum italicum

Abstract

Background Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia.Methods H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA.Key resultsThe Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity.ConclusionsThe results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.

Genetic Diversity and Structure of Populations of Annona crassiflora Mart. of Brazilian Savanna and Its Association with Chemical Variability

“…As far as we know, this is the first study which tentatively explored the correlation between genetic and chemical differentiation among populations of A. crassiflora . Other authors have already reach success using genetic markers (AFLP and/or SAMPL) and essential oil compounds .…”

Chemical composition and biological activity of the essential oil from Helichrysum microphyllum Cambess. ssp. tyrrhenicum Bacch., Brullo e Giusso growing in La Maddalena Archipelago, Sardinia.

“…italicum was proven to exhibit both morphological and genetic variation among and within the Mediterranean and Sardinian populations 9,10 . This variability influenced the volatile composition with quali-quantitative differences in essential oils among populations coming from different regions 11 15 .…”

AFLP fingerprinting and essential oil profiling of cultivated and wild populations of Sardinian Salvia desoleana

“…In this species in fact, the reproductive characteristic and the irregular agricultural practices induced high genetic diversity in cultivated collection of S. miltiorrhiza (Zhang et al 2013 andGuo et al 2002). In particular, higher level of genetic diversity in cultivated germoplasm, rather than in the natural populations, has been previously shown in other plant species such as raspberry (Dosset et al 2010) and myrtle (Melito et al 2013b) where the anthropic selection for industrial purposes inferred a bias in the heterozygosity level in cultivated collections. The rather limited genetic diversity present in the Gergei wild population is probably a consequence of small population size, since most wild populations on the island had disappeared since 30 years ago.…”