Essential Oils, Chromosome Numbers and Karyotypes from Italian<i>Achillea</i>Species. Part II

Abstract

ABSTRACT Six Achillea species—Achilleadistans, Achillea setacea, Achillea collina, Achillea ageratum, Achillea ligustica and Achillea aspleniifolia—growing spontaneously in North Italy, were studied in order to analyze the oil composition and to characterize the chromosome numbers and karyotypes. A total of 69 compounds were identified from all oils, including monoterpenes and sesquiterpenes. The main oil components of A distans were bisabolene oxide and linalyl oxide, while A. setacea had high percentages of the sesquiterpenes β-eudesmol, α-bisabolol and caryophyllene oxide. A. ageratum was characterized by the presence of artemisia acetate, artemisia alcohol, 1, 8-cineole and yomogi alcohol, whereas A. ligustica had high percentages of artemisia ketone. A. collina and A. aspleniifolia were particularly rich in chamazulene along with good percentages of germacrene D and other sesquiterpene hydrocarbons. A. distans had a hexaploid(2n=54)chromosome number, A. setacea and A. collina a tetraploid (2n=36) chromosome number, while A. ageratum, A. ligustica and A. aspleniifolia possessed a diploid (2n=18) chromosome number. In all species the majority of die chromosomes was of the "m" type, followed by some "sm" types. The mean arm "r" ratio of the karyotypes placed the plants into submetacentric category. No correlation was found between oil composition and karyotype formula. The results also confirmed the possibility for diploid (2n=18) Achillea types to synthesize azulenes while the inability of azulene synthesis in some tetraploid (2n=36) and hexaploid (2n=54) types was indicated. KEY WORD INDEX: Achillea distans Achillea setacea Achillea collina Achillea ageratum Achillea ligustica Achillea aspleniifolia Asteraceaeessential oil compositionchromosome numberkaryotypesPrincipal Component Analysis (PCA)