Essential oil variations among the natural populations of Francoeuria undulata

Francoeuria undulata (L.) LACK is often synonymous with two species of the genus Pulicaria, i.e. Pulicaria undulata (L.) C.A. Mey and Pulicaria crispa (Forssk.) olive, which are often included under the genus Francoeuria. The essential oil yield and compositions in the five natural populations of Francoeuria undulata from Fars Province in southern Iran were determined by GC and GC/MS analysis. The essential oil yields ranged between 0.34 and 0.52% (w/w) with a mean of 0.42%, in the five populations studied. Fifty-six compounds were identified in the oil samples, representing 92.9% of the total oil. Eighteen major compounds detected in the oil samples at an average concentration of about 1% of the total oil in the five populations have been considered for statistical analyses. The main components included 1,8- cineol (21.1%), alloaromadendrene epoxide (16.9%), eudesma-4(15),7-dien-1-ß-ol (15.7%), α- terpineol (8.1%), α-pinene (5.0%) and terpinen-4-ol (5.0%). By evaluating the changes in the essential oil components, we have concluded the existence of a high intraspecific genetic variation among the Francoeuria undulata populations. Based on the canonical discriminant functions the analysis enabled the identification of four chemotypes. Moreover, the presence of trans-methyl dihydrojasmonate and high levels of oxygenated mono- and sesquiterpenes in the essential oils of the plant, indicate the high chemical defensive ability of Francoeuria undulata.