title: Intra-specific variability of ozone sensitivity in Centaurea jacea L., a potential bioindicator for elevated ozone concentrations.
abstract: Brown knapweed (Centaurea jacea L.) has been suggested as a potential bioindicator for tropospheric ozone (O3), but little is known about the intra-specific variation in O3 sensitivity in this wild species. The aim of this study was to quantify the differences in O3 sensitivity among and within five populations, and to relate the differences to morphological, phenological, and genetic characteristics. These parameters were periodically recorded in two consecutive experiments on a total of 357 plants from five different European countries (Norway, Hungary, Switzerland, Italy, Slovenia). They were grown from seed in natural soil under ambient conditions at a site with seasonally elevated O3 concentrations (Cadenazzo, southern Switzerland). The populations differed significantly both in frequency and extent of O3 injury, as well as in phenological development. The observed degree of O3 injury was highest in the Slovenian and the Swiss populations, while only few Hungarian and Norwegian plants showed slight symptoms of injury. Plants were generally most sensitive to O3 when reaching the reproductive stage, and insensitive at the rosette stage. Amplified fragment length polymorphism analysis (AFLP) demonstrated genetic distinctiveness of the five C. jacea populations. All individuals of four of the five populations were correctly assigned to the respective populations based on principal component analysis. Cluster analysis quite accurately reflected the geographic origin of each population. Overall, the analysis revealed a high degree of intra-specific variability in O3 sensitivity in C. jacea, and underlined the important influence of the climate-dependent population-specific plant development on O3 sensitivity. These observations may constrain the development of a standardized biomonitoring system.
authors.affiliation: Swiss Federal Research Station for Agroecology and Agriculture (FAL), Reckenholzstrasse 191, CH-8046 Zurich, Switzerland. seraina.bassin@fal.admin.ch
authors.forename: Seraina
authors.initials: S
authors.lastname: Bassin
authors.forename: Roland
authors.initials: R
authors.lastname: Kölliker
authors.forename: Christine
authors.initials: C
authors.lastname: Cretton
authors.forename: Mario
authors.initials: M
authors.lastname: Bertossa
authors.forename: Franco
authors.initials: F
authors.lastname: Widmer
authors.forename: Patrick
authors.initials: P
authors.lastname: Bungener
authors.forename: Jürg
authors.initials: J
authors.lastname: Fuhrer
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D031179:Centaurea / Q000187:drug effects* / Q000235:genetics; D016000:Cluster Analysis; D004784:Environmental Monitoring / Q000379:methods*; D005060:Europe; D010126:Ozone / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects; D011110:Polymorphism, Genetic; D013045:Species Specificity
chemical_list: D000393:Air Pollutants; D010126:Ozone